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Arita J, Kiritani S, Ichida A, Kawaguchi Y, Akamatsu N, Kaneko J, Hasegawa K. 497P Prognostic impact of venous and lymphatic invasion of pancreatic neuroendocrine neoplasm in patients undergoing resection. Ann Oncol 2022. [DOI: 10.1016/j.annonc.2022.07.625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Kawaguchi Y, Hasegawa K, Tzeng CWD, Mizuno T, Arita J, Sakamoto Y, Chun YS, Aloia TA, Kokudo N, Vauthey JN. Performance of a modified three-level classification in stratifying open liver resection procedures in terms of complexity and postoperative morbidity. Br J Surg 2019; 107:258-267. [PMID: 31603540 DOI: 10.1002/bjs.11351] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 08/05/2019] [Accepted: 08/06/2019] [Indexed: 01/05/2023]
Abstract
BACKGROUND Traditional classifications for open liver resection are not always associated with surgical complexity and postoperative morbidity. The aim of this study was to test whether a three-level classification for stratifying surgical complexity based on surgical and postoperative outcomes, originally devised for laparoscopic liver resection, is superior to classifications based on a previously reported survey for stratifying surgical complexity of open liver resections, minor/major nomenclature or number of resected segments. METHODS Patients undergoing a first open liver resection without simultaneous procedures at MD Anderson Cancer Center (Houston cohort) or the University of Tokyo (Tokyo cohort) were studied. Surgical and postoperative outcomes were compared among three grades: I (wedge resection for anterolateral or posterosuperior segment and left lateral sectionectomy); II (anterolateral segmentectomy and left hepatectomy); III (posterosuperior segmentectomy, right posterior sectionectomy, right hepatectomy, central hepatectomy and extended left/right hepatectomy). RESULTS In both the Houston (1878 patients) and Tokyo (1202) cohorts, duration of operation, estimated blood loss and comprehensive complication index score differed between the three grades (all P < 0·050) and increased in stepwise fashion from grades I to III (all P < 0·001). Left hepatectomy was associated with better surgical and postoperative outcomes than right hepatectomy, extended right hepatectomy and right posterior sectionectomy, although these four procedures were categorized as being of medium complexity in the survey-based classification. Surgical outcomes of minor open liver resections also differed between the three grades (all P < 0·050). For duration of operation and blood loss, the area under the curve was higher for the three-level classification than for the minor/major or segment-based classification. CONCLUSION The three-level classification may be useful in studies analysing open liver resection at Western and Eastern centres.
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Affiliation(s)
- Y Kawaguchi
- Department of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA.,Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - K Hasegawa
- Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - C-W D Tzeng
- Department of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - T Mizuno
- Department of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - J Arita
- Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Y Sakamoto
- Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Y S Chun
- Department of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - T A Aloia
- Department of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - N Kokudo
- National Centre for Global Health and Medicine, Tokyo, Japan
| | - J-N Vauthey
- Department of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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Arita J, Ishizawa T, Akamatsu N, Kaneko J, Hasegawa K. Efficacy of surgical resection in patients with recurrent tumor of intrahepatic cholangiocarcinoma. Ann Oncol 2019. [DOI: 10.1093/annonc/mdz155.180] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Mizuno S, Nakai Y, Tanaka M, Ushiku T, Arita J, Hasegawa K, Fukayama M, Koike K. Gastrointestinal: Reappraisal of the usefulness of percutaneous transhepatic cholangioscopy for indeterminate distal biliary strictures. J Gastroenterol Hepatol 2019; 34:961. [PMID: 30669178 DOI: 10.1111/jgh.14588] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 12/28/2018] [Indexed: 12/12/2022]
Affiliation(s)
- S Mizuno
- Department of Gastroenterology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Y Nakai
- Department of Gastroenterology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - M Tanaka
- Department of Pathology and Diagnostic Pathology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - T Ushiku
- Department of Pathology and Diagnostic Pathology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - J Arita
- Department of Hepatobiliary and Pancreatic Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - K Hasegawa
- Department of Hepatobiliary and Pancreatic Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - M Fukayama
- Department of Pathology and Diagnostic Pathology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - K Koike
- Department of Gastroenterology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
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Takemura N, Aoki T, Hasegawa K, Kaneko J, Arita J, Akamatsu N, Makuuchi M, Kokudo N. Hepatectomy for hepatocellular carcinoma after perioperative management of portal hypertension. Br J Surg 2019; 106:1066-1074. [DOI: 10.1002/bjs.11153] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 01/24/2019] [Accepted: 02/06/2019] [Indexed: 01/27/2023]
Abstract
Abstract
Background
Indications for hepatectomy in patients with hepatocellular carcinoma (HCC) who have portal hypertension (PH) have been controversial. Some studies have concluded that PH is a contraindication to hepatectomy, whereas others have suggested that perioperative prophylactic management (PPM) can help overcome complications after hepatectomy associated with PH. The objective of this retrospective study was to assess the short- and long-term outcomes after hepatectomy for HCC in patients with PH, with or without PPM.
Methods
Records were reviewed of consecutive patients who underwent hepatectomy for HCC, with or without PPM of PH, in a single institution from 1994 to 2015. Patients were divided into three groups: those who received PPM for PH (PPM group), patients who had PH but did not receive PPM (no-PPM group) and those without PH (no-PH group).
Results
A total of 1259 patients were enrolled, including 123 in the PPM group, 181 in the no-PPM group and 955 in the no-PH group. Three- and 5-year overall survival rates were 74·3 and 53·1 per cent respectively in the PPM group, 69·2 and 54·9 per cent in the no-PPM group, and 78·1 and 64·2 per cent in the no-PH group (P = 0·520 for PPM versus no PPM, P = 0·027 for PPM versus no PH, and P < 0·001 for no PPM versus no PH). Postoperative morbidity and mortality rates were 26·0 and 0·8 per cent respectively in the PPM group, 29·8 and 1·1 per cent in the no-PPM group, and 20·3 and 0 per cent in the no-PH group.
Conclusion
The present study has demonstrated acceptable outcomes among patients with HCC who received appropriate management for PH in an Asian population. Enhancement of the safety of hepatic resection through use of PPM may provide a rationale for expansion of indications for hepatectomy in patients with PH.
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Affiliation(s)
- N Takemura
- Department of Surgery, Hepato-Biliary-Pancreatic Surgery Division, Artificial Organ and Transplantation Division, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
- National Centre for Global Health and Medicine, Tokyo, Japan
| | - T Aoki
- Department of Surgery, Hepato-Biliary-Pancreatic Surgery Division, Artificial Organ and Transplantation Division, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - K Hasegawa
- Department of Surgery, Hepato-Biliary-Pancreatic Surgery Division, Artificial Organ and Transplantation Division, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - J Kaneko
- Department of Surgery, Hepato-Biliary-Pancreatic Surgery Division, Artificial Organ and Transplantation Division, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - J Arita
- Department of Surgery, Hepato-Biliary-Pancreatic Surgery Division, Artificial Organ and Transplantation Division, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - N Akamatsu
- Department of Surgery, Hepato-Biliary-Pancreatic Surgery Division, Artificial Organ and Transplantation Division, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | | | - N Kokudo
- National Centre for Global Health and Medicine, Tokyo, Japan
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Arita J, Kokudo T, Akamatsu N, Kaneko J, Ishizawa T, Hasegawa K. Comparison of prognosis after hepatic resection of hepatocellular carcinoma between intermediate stage tumor and early stage tumor. Ann Oncol 2018. [DOI: 10.1093/annonc/mdy150.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Wang L, Mitsui T, Ishida M, Izawa M, Arita J. Rasd1 is an estrogen-responsive immediate early gene and modulates expression of late genes in rat anterior pituitary cells. Endocr J 2017; 64:1063-1071. [PMID: 28835591 DOI: 10.1507/endocrj.ej17-0148] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Dexamethasone-induced Ras-related protein 1 (Rasd1) is a member of the Ras superfamily of monomeric G proteins that have a regulatory function in signal transduction. Here we investigated the role of Rasd1 in regulating estrogen-induced gene expression in primary cultures of rat anterior pituitary cells. Rasd1 mRNA expression in anterior pituitary cells decreased after treatment with forskolin or serum and increased after treatment with 17β-estradiol (E2). Increases in Rasd1 mRNA expression occurred as early as 0.5 h after E2 treatment, peaked at 1 h and were sustained for as long as 96 h. This rapid and profound increase in Rasd1 mRNA expression induced by E2 was also seen in GH4C1 cells, an estrogen receptor-positive somatolactotroph cell line. Among pituitary estrogen-responsive late genes studied, basal mRNA expression of Pim3 and Igf1 genes was decreased by RNA interference-mediated knockdown of Rasd1 expression, whereas basal expression of the Giot1 gene was increased. Moreover, Rasd1 knockdown enhanced stimulation of Pim3 mRNA expression and attenuated inhibition of Fosl1 mRNA expression 24 h after E2 treatment. These changes in mRNA expression were accompanied by enhanced activity of promoters containing CRE, AP-1 and SRE binding sequences. These results suggest that Rasd1 is an estrogen-responsive immediate early gene and modulates E2 induction of at least several late genes in anterior pituitary cells.
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Affiliation(s)
- Linghong Wang
- Department of Physiology, Graduate School of Medicine, University of Yamanashi, Chuo 409-3898, Japan
| | - Tetsuo Mitsui
- Department of Physiology, Graduate School of Medicine, University of Yamanashi, Chuo 409-3898, Japan
| | - Maho Ishida
- Department of Physiology, Graduate School of Medicine, University of Yamanashi, Chuo 409-3898, Japan
| | - Michi Izawa
- Department of Physiology, Graduate School of Medicine, University of Yamanashi, Chuo 409-3898, Japan
| | - Jun Arita
- Department of Physiology, Graduate School of Medicine, University of Yamanashi, Chuo 409-3898, Japan
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Mitsui T, Ishida M, Izawa M, Arita J. Activation of G protein-coupled estrogen receptor 1 mimics, but does not mediate, the anti-proliferative action of estradiol on pituitary lactotrophs in primary culture. Endocr J 2017; 64:103-115. [PMID: 27760898 DOI: 10.1507/endocrj.ej16-0079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Estrogen binds to nuclear estrogen receptors (ERs) to modulate transcription of target genes in estrogen-responsive cells. However, recent studies have shown that estrogen also binds to cytoplasmic membrane ERs to modulate protein kinase signaling cascades, leading to non-genomic actions. We investigated whether either nuclear or membrane ERs, including G protein-coupled estrogen receptor 1 (Gper1), mediate the inhibitory action of estrogen on insulin-like growth factor-1 (IGF-1)-induced proliferation of pituitary lactotrophs in primary culture. The cytoplasmic membrane-impermeable bovine serum albumin-conjugated estradiol (BSA-E2) at 1 nM, an equimolar concentration at which 17β-estradiol (E2) exerts anti-proliferative effects, did not inhibit IGF-1-induced lactotroph proliferation. In contrast, diethylstilbestrol, which is known to selectively activate nuclear ERs but not membrane ERs, inhibited IGF-1-induced proliferation and modulated mRNA expression of estrogen-responsive genes to a similar degree as E2. Activation of Gper1 by its agonist G-1 inhibited IGF-1-induced proliferation in a dose-dependent manner, but it had little effect on modulation of mRNA expression of estrogen-responsive genes. However, blockade of Gper1 by its antagonist G-15 did not affect the inhibitory action of E2 on IGF-1-induced proliferation. Here, we demonstrate that E2 inhibition of lactotroph proliferation is due to nuclear ER-mediated genomic action. Our results suggest that activation of Gper1 mimics, but does not mediate, the anti-proliferative action of E2 on lactotrophs.
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Affiliation(s)
- Tetsuo Mitsui
- Department of Physiology, Graduate School of Medicine, University of Yamanashi, Yamanashi 409-3898, Japan
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Kokudo T, Hasegawa K, Arita J, Yamamoto S, Kaneko J, Akamatsu N, Sakamoto Y, Makuuchi M, Sugawara Y, Kokudo N. Use of a Right Lateral Sector Graft in Living Donor Liver Transplantation Is Feasible, but Special Caution Is Needed With Respect to Liver Anatomy. Am J Transplant 2016; 16:1258-65. [PMID: 26602536 DOI: 10.1111/ajt.13604] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 10/02/2015] [Accepted: 10/31/2015] [Indexed: 01/25/2023]
Abstract
Right lateral sector (RLS) grafting has been introduced to enlarge the potential donor pool for living donor liver transplantation (LDLT); however, evidence of its feasibility is limited. Data from 437 LDLTs carried out between 2000 and 2013 were analyzed retrospectively. LDLTs using a right liver graft (n = 251) were compared with those using a RLS graft (RLSG; n = 28). No donor mortality occurred, and the major complication rates were similar between the two groups. Postoperative liver function preservation was better in the RLSG donors. Concerning the recipients, the mortality and overall survival rates were similar between the two groups. The complication rate for the recipients was higher when more than two arterial or biliary anastomoses were necessary. A systematic literature search identified four reports on LDLT using RLSGs. Among 66 LDLTs, including the present series, there were no cases of donor death, and the rates of major and minor complications in the donors were 6% and 29%, respectively. The major complication and overall mortality rates in the recipients were 29% and 6%, respectively. LDLT using an RLSG is feasible, with an acceptable survival rate among the recipients.
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Affiliation(s)
- T Kokudo
- Hepato-Biliary-Pancreatic Surgery Division and Artificial Organ and Transplantation Division, Department of Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - K Hasegawa
- Hepato-Biliary-Pancreatic Surgery Division and Artificial Organ and Transplantation Division, Department of Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - J Arita
- Hepato-Biliary-Pancreatic Surgery Division and Artificial Organ and Transplantation Division, Department of Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - S Yamamoto
- Hepato-Biliary-Pancreatic Surgery Division and Artificial Organ and Transplantation Division, Department of Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - J Kaneko
- Hepato-Biliary-Pancreatic Surgery Division and Artificial Organ and Transplantation Division, Department of Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - N Akamatsu
- Hepato-Biliary-Pancreatic Surgery Division and Artificial Organ and Transplantation Division, Department of Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Y Sakamoto
- Hepato-Biliary-Pancreatic Surgery Division and Artificial Organ and Transplantation Division, Department of Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - M Makuuchi
- Division of Hepato-Biliary-Pancreatic Surgery, Japanese Red Cross Medical Center, Tokyo, Japan
| | - Y Sugawara
- Hepato-Biliary-Pancreatic Surgery Division and Artificial Organ and Transplantation Division, Department of Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - N Kokudo
- Hepato-Biliary-Pancreatic Surgery Division and Artificial Organ and Transplantation Division, Department of Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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Fukasawa Y, Ohno N, Saitoh Y, Saigusa T, Arita J, Ohno S. Immunohistochemical and morphofunctional studies of skeletal muscle tissues with electric nerve stimulation by in vivo cryotechnique. Acta Histochem Cytochem 2015; 48:27-36. [PMID: 26019372 PMCID: PMC4427562 DOI: 10.1267/ahc.14068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Accepted: 03/03/2015] [Indexed: 11/22/2022] Open
Abstract
In this study, morphological and immunohistochemical alterations of skeletal muscle tissues during persistent contraction were examined by in vivo cryotechnique (IVCT). Contraction of gastrocnemius muscles was induced by sciatic nerve stimulation. The IVCT was performed immediately, 3 min or 10 min after the stimulation start. Prominent ripples of muscle fibers or wavy deformation of sarcolemma were detected immediately after the stimulation, but they gradually diminished to normal levels during the stimulation. The relative ratio of sarcomere and A band lengths was the highest in the control group, but it immediately decreased to the lowest level and then gradually recovered at 3 min or 10 min. Although histochemical intensity of PAS reaction was almost homogeneous in muscle tissues of the control group or immediately after the stimulation, it decreased at 3 min or 10 min. Serum albumin was immunolocalized as dot-like patterns within some muscle fibers at 3 min stimulation. These patterns became more prominent at 10 min, and the dots got larger and saccular in some sarcoplasmic regions. However, IgG1 and IgM were immunolocalized in blood vessels under nerve stimulation conditions. Therefore, IVCT was useful to capture the morphofunctional and metabolic changes of heterogeneous muscle fibers during the persistent contraction.
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Affiliation(s)
- Yuki Fukasawa
- Department of Anatomy and Molecular Histology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi
| | - Nobuhiko Ohno
- Department of Anatomy and Molecular Histology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi
| | - Yurika Saitoh
- Department of Anatomy and Molecular Histology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi
| | - Takeshi Saigusa
- First Department of Physiology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi
| | - Jun Arita
- First Department of Physiology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi
| | - Shinichi Ohno
- Department of Anatomy and Molecular Histology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi
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Ono Y, Matsueda K, Koga R, Takahashi Y, Arita J, Takahashi M, Inoue Y, Unno T, Saiura A. Sinistral portal hypertension after pancreaticoduodenectomy with splenic vein ligation. Br J Surg 2014; 102:219-28. [PMID: 25524295 DOI: 10.1002/bjs.9707] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 09/22/2014] [Accepted: 10/16/2014] [Indexed: 12/16/2022]
Abstract
BACKGROUND Splenic vein ligation may result in sinistral (left-sided) portal hypertension and gastrointestinal haemorrhage. The aim of this study was to analyse the pathogenesis of sinistral portal hypertension following splenic vein ligation in pancreaticoduodenectomy. METHODS Patients who underwent pancreaticoduodenectomy for pancreatic cancer between January 2005 and December 2012 were included in this retrospective study. The venous flow pattern from the spleen and splenic hypertrophy were examined after surgery. RESULTS Of 103 patients who underwent pancreaticoduodenectomy with portal vein resection, 43 had splenic vein ligation. There were two predominant venous flow patterns from the spleen. In the varicose route (27 patients), flow from the spleen passed to colonic varices and/or other varicose veins. In the non-varicose route, flow from the spleen passed through a splenocolonic collateral (14 patients) or a spontaneous splenorenal shunt (2 patients). The varicose route was associated with significantly greater splenic hypertrophy than the non-varicose route (median splenic hypertrophy ratio 1·52 versus 0·94; P < 0·001). All patients with the varicose route had colonic varices, and none had a right colic marginal vein at the hepatic flexure. CONCLUSION Pancreaticoduodenectomy with splenic vein ligation may lead to sinistral portal hypertension. To avoid the development of varices, it is important to preserve the right colic marginal vein. Reconstruction of the splenic vein should be considered if the right colic marginal vein is divided.
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Affiliation(s)
- Y Ono
- Departments of Gastroenterological Surgery, Cancer Institute Hospital, Japanese Foundation for Cancer Research, Tokyo, Japan
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12
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Saigusa T, Arita J. ANG II modulates both slow and rapid baroreflex responses of barosensitive bulbospinal neurons in the rabbit rostral ventrolateral medulla. Am J Physiol Regul Integr Comp Physiol 2014; 306:R538-51. [DOI: 10.1152/ajpregu.00285.2013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This study investigated the effects of ANG II on slow and rapid baroreflex responses of barosensitive bulbospinal neurons in the rostral ventrolateral medulla (RVLM) in urethane-anesthetized rabbits to determine whether the sympathetic baroreflex modulation induced by application of ANG II into the RVLM can be explained by the total action of ANG II on individual RVLM neurons. In response to pharmacologically induced slow ramp changes in mean arterial pressure (MAP), individual RVLM neurons exhibited a unit activity-MAP relationship that was fitted by a straight line with upper and lower plateaus. Iontophoretically applied ANG II raised the upper plateau without changing the slope, and, thereby, increased the working range of the baroreflex response. An asymmetric sigmoid curve that was determined by averaging individual unit activity-MAP relationship lines became more symmetric with ANG II application. The characteristics of the average curves, both before and during ANG II application, were consistent with the renal sympathetic nerve activity-MAP relationship curves obtained under the same experimental conditions. ANG II also affected rapid baroreflex responses of RVLM neurons that were induced by cardiac beats, as application of ANG II predominantly raised the average unit activities in the downstroke phase of arterial pulse waves. The present study provides a possible explanation for the ANG II-induced sympathetic baroreflex modulation based on the action of ANG II on barosensitive bulbospinal RVLM neurons. Our results also suggest that ANG II changes both static and dynamic characteristics of baroreflex responses of RVLM neurons.
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Affiliation(s)
- Takeshi Saigusa
- Department of Physiology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, Japan
| | - Jun Arita
- Department of Physiology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi, Japan
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Ishida M, Mitsui T, Izawa M, Arita J. Activation of D2 dopamine receptors inhibits estrogen response element-mediated estrogen receptor transactivation in rat pituitary lactotrophs. Mol Cell Endocrinol 2013; 375:58-67. [PMID: 23701824 DOI: 10.1016/j.mce.2013.05.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 04/15/2013] [Accepted: 05/10/2013] [Indexed: 11/21/2022]
Abstract
Estrogen and dopamine are major opposing regulators of the endocrine functions of pituitary lactotrophs. Dopamine inhibits estrogen-induced changes in the synthesis and secretion of prolactin, and lactotroph proliferation. We studied the mechanism of the inhibitory effects of dopaminergic stimulation on estrogen-induced functional changes of rat lactotrophs in primary culture. The dopaminergic agonist, bromocriptine (BC), suppressed 17β-estradiol-stimulated lactotroph proliferation, prolactin promoter activity, and mRNA expression of some estrogen-responsive genes. In lactotroph-enriched pituitary cells, BC treatment inhibited the estrogen response element (ERE) DNA sequence-mediated estrogen receptor (ER) transcriptional activity. Using a lactotroph-specific ERE transcriptional assay, we found that BC inhibition of the ERE-mediated ER transcriptional activity partly involved D2 dopamine receptor-mediated, pertussis toxin-sensitive G protein-coupled, cAMP/protein kinase A-dependent signaling. BC treatment had no effect on the cellular concentration of ERα or its phosphorylation status at Ser-118. Similar transcriptional inhibition by BC was also found in GH4ZR7 cells, a D2 dopamine receptor-expressing somatomammotrophic cell line. These results suggest that activation of the D2 dopamine receptors inhibits estrogen-dependent lactotroph functions in part via attenuation of ERE-mediated ER transactivation.
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Affiliation(s)
- Maho Ishida
- Department of Physiology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi 409-3898, Japan.
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Kawaguchi Y, Aoki T, Ishizawa T, Arita J, Satou S, Kaneko J, Sakamoto Y, Sugawara Y, Hasegawa K, Kokudo N. Education and imaging: Hepatobiliary and pancreatic: Identification of recurrent hepatocellular carcinoma by intraoperative fluorescent imaging. J Gastroenterol Hepatol 2013; 28:587. [PMID: 23565552 DOI: 10.1111/jgh.12095] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Affiliation(s)
- Y Kawaguchi
- Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
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Mitsui T, Ishida M, Izawa M, Arita J. Differences between rat strains in the development of PRL-secreting pituitary tumors with long-term estrogen treatment: In vitro insulin-like growth factor-1-induced lactotroph proliferation and gene expression are affected in Wistar-Kyoto rats with low estrogen-susceptibility. Endocr J 2013; 60:1251-9. [PMID: 23985690 DOI: 10.1507/endocrj.ej13-0245] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
There are differences in the susceptibility of rat strains to pituitary growth and lactotroph proliferation caused by long-term treatment with estrogens. To investigate the pituitary mechanism for this strain difference in estrogen-induced lactotroph proliferation, we compared the abilities of 17-β estradiol (E2) and insulin-like growth factor-1 (IGF-1) to modulate lactotroph proliferation and gene expression in vitro in Wistar and Wistar-Kyoto (WKY) rats. These two strains of rats have a high and very low susceptibility to estrogen, respectively. Long-term in vivo treatment with E2 was confirmed to markedly increase pituitary weight and lactotroph proliferation in ovariectomized Wistar, but not in WKY rats. Pituitary lactotrophs in primary cultures showed similar proliferative responsiveness to the culture condition-dependent, stimulatory and inhibitory actions of E2 in both strains. The only difference in lactotroph proliferation in vitro was a lower response to IGF-1 in WKY cells compared with Wistar cells. This difference in proliferation was associated with strain differences in IGF-1-induced gene expression in Wistar and WKY cultured cells. Of the genes tested, IGF-1-induced expression of the Wnt4, Stc1, Mybl1, and Myc genes was attenuated or abolished in WKY cells. These results suggest that the proliferative response to estrogen in lactotrophs in primary culture does not reflect the proliferative response to long-term estrogen treatment observed in vivo in Wistar and WKY rats. The strain difference in proliferation and gene expression to IGF-1 may be implicated in the variable degree of susceptibility for lactotroph proliferation observed in different strains of rats following long-term estrogen treatment.
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Affiliation(s)
- Tetsuo Mitsui
- Department of Physiology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo 409-3898, Japan
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Takahashi M, Hasegawa K, Arita J, Hata S, Aoki T, Sakamoto Y, Sugawara Y, Kokudo N. Contrast-enhanced intraoperative ultrasonography using perfluorobutane microbubbles for the enumeration of colorectal liver metastases. Br J Surg 2012; 99:1271-7. [PMID: 22829436 DOI: 10.1002/bjs.8844] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2012] [Indexed: 12/14/2022]
Abstract
BACKGROUND Intraoperative ultrasonography (IOUS) is considered the standard for the identification of liver metastases. Use of lipid-stabilized perfluorobutane microbubbles as an ultrasound contrast agent may improve this. The value of contrast-enhanced IOUS (CE-IOUS) in enumerating colorectal liver metastases was studied here. METHODS CE-IOUS was performed in consecutive resections for colorectal liver metastases in 2007-2010. All patients underwent preoperative computed tomography. Magnetic resonance imaging was not carried out routinely. Conventional intraoperative examination including IOUS, and CE-IOUS with peripherally injected contrast were performed. The histopathological findings and 6-month follow-up images were used as the reference standard. RESULTS The study group of 102 patients had a total of 315 lesions identified on preoperative imaging (2·4 lesions per operation; 129 operations). Conventional intraoperative examination including IOUS identified 350 lesions (2·7 per operation). CE-IOUS identified 370 lesions (2·9 per operation). The sensitivity, specificity and accuracy of CE-IOUS were 97·1, 59·1 and 93·2 per cent respectively. The CE-IOUS findings altered the surgical plan in 19 operations (14·7 per cent). CONCLUSION CE-IOUS provided additional information to that obtained using contemporary preoperative imaging and conventional intraoperative examinations.
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Affiliation(s)
- M Takahashi
- Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, Graduate School of Medicine, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
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Mitsui T, Ishida M, Izawa M, Kagami Y, Arita J. Inhibition of Bcl3 gene expression mediates the anti-proliferative action of estrogen in pituitary lactotrophs in primary culture. Mol Cell Endocrinol 2011; 345:68-78. [PMID: 21787835 DOI: 10.1016/j.mce.2011.07.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 06/09/2011] [Accepted: 07/08/2011] [Indexed: 01/13/2023]
Abstract
In addition to their well-known stimulatory action, estrogens have an anti-proliferative effect. The present study was undertaken to investigate the mechanism by which 17β-estradiol (E2) inhibits insulin-like growth factor-1 (IGF-1)-induced proliferation in vitro in the rat pituitary lactotroph, a typical estrogen-responsive cell. E2 treatment of pituitary cells did not change levels of IGF-1-induced phosphorylation of proliferation-related protein kinases such as Erk1/2 and Akt. We performed global gene expression profiling by DNA microarray analysis and identified 177 genes regulated by E2 in the presence of IGF-1. These results were verified by quantitative real time PCR. The estrogen-regulated genes included several NFκB family related genes. As pharmacological inhibition of the NFκB pathway blocked IGF-1-induced lactotroph proliferation, we chose to investigate whether one NFκB pathway gene, Bcl3, was involved in the anti-proliferative action of E2. RNA interference-mediated knockdown of Bcl3 expression attenuated IGF-1-induced lactotroph proliferation. Even minimal induced overexpression of Bcl3 blocked the anti-proliferative action of E2. In contrast, Nfkb2, another E2-downregulated protein, required maximal overexpression to block the anti-proliferative action of E2. These results suggest that inhibition of Bcl3 expression is involved in the anti-proliferative action of estrogens in pituitary lactotrophs in culture.
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Affiliation(s)
- Tetsuo Mitsui
- Department of Physiology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Japan
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Mitsui T, Taniguchi N, Kawasaki N, Kagami Y, Arita J. Fetal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin induces expression of the chemokine genes Cxcl4 and Cxcl7 in the perinatal mouse brain. J Appl Toxicol 2011; 31:279-84. [DOI: 10.1002/jat.1612] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2010] [Revised: 08/10/2010] [Accepted: 10/08/2010] [Indexed: 12/14/2022]
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Iguchi H, Mitsui T, Ishida M, Kanba S, Arita J. cAMP response element-binding protein (CREB) is required for epidermal growth factor (EGF)-induced cell proliferation and serum response element activation in neural stem cells isolated from the forebrain subventricular zone of adult mice. Endocr J 2011; 58:747-59. [PMID: 21701076 DOI: 10.1507/endocrj.k11e-104] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Neurogenesis, which occurs not only in the developing brain but also in restricted regions in the adult brain including the forebrain subventricular zone (SVZ), is regulated by a variety of environmental factors, extracellular signals, and intracellular signal transduction pathways. We investigated whether the transcription factor cAMP response element (CRE)-binding protein (CREB) is involved in the regulation of cell proliferation of neural stem cells (NSCs) isolated from the SVZ of adult mice. Treatment of NSCs with the protein kinase A (PKA) inhibitors H89 and KT5720 inhibited epidermal growth factor (EGF)-stimulated NSC proliferation. Similar inhibition was observed when a dominant-negative mutant of CREB (MCREB) was expressed. EGF treatment increased CRE-mediated transcriptional activity, but this increase was much less than that caused by treatment with the adenylate cyclase activator forskolin, which changed neither basal nor EGF-stimulated proliferation of NSCs. Neither PKA inhibitors nor MCREB expression blocked EGF-induced phosphorylation of extracellular signal-regulated kinase (ERK), a protein kinase mediating EGF's mitogenic action. However, MCREB suppressed EGF-induced expression of several immediately early genes including c-fos, c-jun, jun-B, and fra-1 and subsequent AP-1 transcriptional activation. MCREB expression also inhibited the ability of EGF to stimulate transcriptional activation mediated by the serum response element (SRE), a promoter sequence regulating c-fos gene expression. These results suggest that basal activity of CREB is required for the mitogenic signaling of EGF in NSCs at a level between ERK activation and SRE-mediated transcriptional activation.
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Affiliation(s)
- Hironobu Iguchi
- Department of Physiology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, Japan
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Arita J, Woodman G. Simultaneous neurophysiological measurement of perceptual and response selection stages of processing during visual search. J Vis 2010. [DOI: 10.1167/10.7.1319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Ishida M, Mitsui T, Izawa M, Arita J. Absence of ligand-independent transcriptional activation of the estrogen receptor via the estrogen response element in pituitary lactotrophs in primary culture. J Steroid Biochem Mol Biol 2010; 118:93-101. [PMID: 19883758 DOI: 10.1016/j.jsbmb.2009.10.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Revised: 10/19/2009] [Accepted: 10/20/2009] [Indexed: 11/25/2022]
Abstract
The estrogen receptor (ER) is a ligand-activated transcription factor that enhances gene expression by binding to specific regulatory DNA sequences called estrogen response elements (EREs). In some cell lines, the ER is also activated in a ligand-independent manner by multiple signaling pathways. In this study, we developed a novel adenovirus-mediated assay for promoter activation, termed LASETA, which we then used to examine whether ligand-independent activation of the ER occurred in normal pituitary lactotrophs in primary culture. In the LASETA adenovirus vector, the loxP-flanked stop sequence was deleted by prolactin (PRL) promoter-regulated expression of Cre recombinase. This led to lactotroph-specific expression of a reporter gene driven by an ERE-containing promoter. Estrogen-induced expression of the reporter protein luciferase in LASETA was specific for lactotrophs and was ER-dependent. LASETA was shown to be reliable even with varying Cre recombinase expression levels, which were caused by changes in PRL promoter activity. Using LASETA, we observed no change in ERE-mediated ER activity in the absence of estrogen after treatment of normal lactotrophs with agents such as insulin-like growth factor-1, epidermal growth factor, the adenylate cyclase activator forskolin, the extracellular signal-regulated kinase kinase inhibitor U0126, and the protein kinase A inhibitor H89. The ERE-mediated ligand-independent ER activity was induced by the growth factors and forskolin in the somatolactotroph tumor cell line GH4C1 cells. These results suggest that ERE-mediated ligand-independent activation of ER does not occur in normal lactotrophs in primary culture, and is a phenomenon likely restricted to transformed cells.
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Affiliation(s)
- Maho Ishida
- Department of Physiology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi, Japan
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Hagiwara H, Ishida M, Arita J, Mitsushima D, Takahashi T, Kimura F, Funabashi T. The cAMP response element-binding protein in the bed nucleus of the stria terminalis modulates the formalin-induced pain behavior in the female rat. Eur J Neurosci 2009; 30:2379-86. [PMID: 19968712 DOI: 10.1111/j.1460-9568.2009.07002.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Abstract Differences in male and female responses to pain are widely recognized in many species, including humans, but the cerebral mechanisms that generate these responses are unknown. Using the formalin test, we confirmed that proestrus female rats showed nociceptive behavior, modulated by estrogen that was distinct from male rats, particularly during the interphase period. We then explored the brain areas, which were involved in the female pattern of nociceptive behavior. We found that, after a formalin injection and at the time corresponding to the behavioral interphase, the number of phosphorylated cAMP response element-binding protein (pCREB)-immunoreactive neurons observed by immunocytochemistry increased in the dorsolateral division of the bed nucleus of the stria terminalis (BSTLD) in female but not male rats. There were no significant sex differences in pCREB expression following formalin in any region other than the BSTLD. The increased pCREB in female rats was eliminated after an ovariectomy and restored with 17beta-estradiol treatment. Neither an orchidectomy nor 17beta-estradiol treatment affected the pCREB response in male rats. The increase in pCREB expression in the BSTLD in female rats after formalin injection was confirmed with immunoblotting. To determine the role of CREB in the BSTLD, adenovirus-mediated expression of a dominant-negative form of CREB (mCREB) was carried out. The nociceptive behavior during interphase was significantly attenuated by injection of virus carrying mCREB into the BSTLD in female rats but not in male rats. These results suggest a novel role for CREB in the BSTLD as a modulator of the pain response in a female-specific, estrogen-dependent manner.
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Affiliation(s)
- Hiroko Hagiwara
- Department of Physiology, Yokohama City University School of Medicine, Yokohama, Japan
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Wang Z, Mitsui T, Ishida M, Arita J. Adenovirus vectors differentially modulate proliferation of pituitary lactotrophs in primary culture in a mitogen and infection time-dependent manner. J Endocrinol 2008; 198:209-17. [PMID: 18577572 DOI: 10.1677/joe-08-0102] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Adenoviruses are powerful, widely utilized vectors for gene transfer. Limitations to their application, however, have not been well described. We used rat pituitary lactotrophs in primary culture as a model for studying how adenovirus vector infection modulates mitogen-induced proliferation and the activities of mitogen signaling pathways. Infection with adenovirus vectors expressing beta-galactosidase (betagal) raised basal proliferative levels and blocked fetal bovine serum (FBS)-induced proliferation of lactotrophs, but did not influence the changes in proliferation induced by forskolin, IGF-I, and bromocriptine. The betagal-expressing adenoviruses did not alter the inhibitory action of 17beta-estradiol (E(2)) in the presence of IGF-I; however, they blocked the stimulatory action of E(2) in the presence of dextran-coated charcoal-striped serum or forskolin. An adenovirus expressing no protein failed to block FBS-induced proliferation, but was effective in modulating basal proliferative levels and the stimulatory actions of E(2). The increased basal proliferative level and the blockade of FBS-induced proliferation were transient, and lost 5 days after infection while the blockade of the stimulatory action of E(2) in the presence of forskolin persisted. Adenovirus infection raised basal protein levels of the phosphorylated forms of cAMP response element-binding protein (pCREB) and ERK1/2 and increased the proportion of pCREB-immunoreactive lactotrophs. Adenoviruses also altered estrogen-induced responses in mRNA expression of several estrogen-responsive genes in a gene-specific manner. The results demonstrate that an adenovirus vector differentially interferes with lactotroph proliferation in response to various mitogens. Our results suggest that the effects of the adenovirus that are independent of the genes transferred must be considered when performing adenoviral gene transfer in the primary cultures of normal cells.
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Affiliation(s)
- Zhenhua Wang
- Department of Physiology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi 409-3898, Japan
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Qin LQ, Xu JY, Tezuka H, Li J, Arita J, Hoshi K, Sato A. Consumption of commercial whole and non-fat milk increases the incidence of 7,12-dimethylbenz(a)anthracene-induced mammary tumors in rats. ACTA ACUST UNITED AC 2008; 31:339-43. [PMID: 17935906 DOI: 10.1016/j.cdp.2007.04.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2007] [Indexed: 11/15/2022]
Abstract
BACKGROUND Breast cancer has become the most common cancer among women worldwide. Although the consumptions of milk and dairy products were considered to be a risk factor for breast cancer in some epidemiological studies, the results were inconsistent. METHODS In the present study, female Sprague-Dawley rats received a single oral dose of 5mg 7,12-dimethylbenz(a)anthracene (DMBA). One week later, the animals were divided into four groups: whole milk (WM), artificial whole milk (A-WM), non-fat milk (NFM) or artificial non-fat milk (A-NFM) mixed with commercial powder chow. Rats were palpated weekly to monitor tumor development. At week 20 after DMBA administration, rats were decapitated and the volume and weight of mammary tumor were recorded. RESULTS Tumor incidence, the cumulative number of tumors and the sums of tumor volume were higher in the WM and NFM groups than in the A-WM and A-NFM groups both at palpation and at autopsy. CONCLUSION Combining our previous studies, we found the consumption of milk promoted the development of DMBA-induced mammary tumors in rats independent of the fat level.
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Affiliation(s)
- Li-Qiang Qin
- Department of Obstetrics & Gynecology, School of Medicine, Yamanashi University, Chuo City, Shimokato 1110, Yamanashi 409-3898, Japan.
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Ishida M, Mitsui T, Yamakawa K, Sugiyama N, Takahashi W, Shimura H, Endo T, Kobayashi T, Arita J. Involvement of cAMP response element-binding protein in the regulation of cell proliferation and the prolactin promoter of lactotrophs in primary culture. Am J Physiol Endocrinol Metab 2007; 293:E1529-37. [PMID: 17925456 DOI: 10.1152/ajpendo.00028.2007] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypothalamic hormones, including dopamine, regulate critical functions of pituitary cells via the cAMP-protein kinase A (PKA) pathway. The PKA-downstream transcription factor cAMP response element (CRE)-binding protein (CREB) is an integrating molecule that is also activated by many other protein kinase pathways. We investigated the involvement of CREB in the regulation of cell proliferation and the PRL promoter of rat lactotrophs in primary cell culture. Recombinant adenoviruses were used for efficient gene delivery into pituitary cells. Bromocriptine, a dopaminergic agonist known to decrease intracellular cAMP concentrations, caused inhibition of PRL promoter activity and lactotroph proliferation, which was accompanied by decreases in CRE-mediated transcription and CREB phosphorylation in lactotrophs. Expression of a dominant-negative form of CREB (MCREB), which was effective in suppressing CRE-mediated transcription induced by the adenylate cyclase activator forskolin, inhibited basal and forskolin-induced PRL promoter activity and PRL mRNA expression. MCREB expression lowered basal proliferative levels and blocked forskolin-induced proliferation of lactotrophs. Insulin-like growth factor I (IGF-I), a potent mitogen in lactotrophs, did not affect intracellular cAMP concentrations but transiently increased lactotroph CREB phosphorylation. MCREB expression also inhibited IGF-I-induced lactotroph proliferation. These results suggest that CREB is involved in the regulation of cell proliferation and the PRL promoter in normal lactotrophs and that dopamine inhibition of these lactotroph functions is at least in part due to inhibition of the cAMP-PKA-CREB pathway.
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Affiliation(s)
- Maho Ishida
- Dept. of Physiology, Interdisciplinary Graduate School of Medicine and Engineering, Univ. of Yamanashi, 409-3898, Japan
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Ishida M, Takahashi W, Itoh S, Shimodaira S, Maeda S, Arita J. Estrogen actions on lactotroph proliferation are independent of a paracrine interaction with other pituitary cell types: a study using lactotroph-enriched cells. Endocrinology 2007; 148:3131-9. [PMID: 17412817 DOI: 10.1210/en.2006-1484] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The mitogenic action of estrogen on estrogen-responsive tissues is suggested to be mediated by paracrine growth factors secreted from neighboring estrogen receptor-positive cells. Using pituitary lactotrophs in primary culture, on which estrogen exerts both mitogenic and antimitogenic actions in a cell context-dependent manner, we investigated whether a paracrine cell-to-cell interaction with other pituitary cell types was required for estrogen action. In pituitary cells, enriched for lactotrophs by 85% using differential sedimentation on a discontinuous Percoll gradient, 17beta-estradiol (E2) showed an antimitogenic action on lactotrophs in the presence of IGF-I, which was similar to that in control unenriched cells. Mitogenic actions were also seen in lactotroph-enriched cells when E2 was administered alone, in combination with serum, or in combination with the adenylate cyclase activator forskolin. Similar results were obtained in 90% lactotroph-enriched cells collected by fluorescence-activated cell sorting from transgenic rats expressing enhanced green fluorescent protein under the control of the prolactin promoter. The putative role of basic fibroblast growth factor (bFGF) as a paracrine factor mediating the mitogenic action of estrogen was not supported by the results that: 1) bFGF inhibited lactotroph proliferation; 2) immunoneutralization of bFGF failed to block E2-induced proliferation; and 3) cellular bFGF levels were not altered by E2 treatment. These results suggest that the antimitogenic and mitogenic actions of estrogen on lactotrophs do not require paracrine signals from other pituitary cell types and that estrogen directly influences lactotroph proliferation.
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Affiliation(s)
- Maho Ishida
- Department of Physiology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi 409-3898, and Division of Blood Transfusion, Shinshu University Hospital, Nagano, Japan
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Bu N, Tsuji T, Arita J, Ohga M. Phoneme classification for speech synthesiser using differential EMG signals between muscles. Conf Proc IEEE Eng Med Biol Soc 2007; 2005:5962-6. [PMID: 17281619 DOI: 10.1109/iembs.2005.1615849] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
This paper proposes the use of differential electromyography (EMG) signals between muscles for phoneme classification, with which a Japanese speech synthesiser system can be constructed using fewer electrodes. In distinction from traditional methods using differential EMG signals between bipolar electrodes on the same muscle, an EMG signal is derived as differential between monopolar signals on two different muscles in the proposed method. Then, frequency-based feature patterns are extracted with filter banks, and classification of phonemes is realized by using a probabilistic neural network, which combines feature reduction and pattern classification processes in a single network structure. Experimental results show that the proposed method can achieve considerably high classification performance with fewer electrodes.
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Affiliation(s)
- Nan Bu
- Department of the, Artificial Complex Systems Engineering, Hiroshima University, Higashi-Hiroshima, 739-8527 Japan.
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Fukushima A, Yin P, Ishida M, Sugiyama N, Arita J. Pup removal suppresses estrogen-induced surges of LH secretion and activation of GnRH neurons in lactating rats. J Endocrinol 2006; 191:339-48. [PMID: 17065416 DOI: 10.1677/joe.1.06728] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
During lactation, the suckling stimulus exerts profound influences on neuroendocrine regulation in nursing rats. We examined the acute effect of pup removal on the estrogen-induced surge of LH secretion in ovariectomized lactating rats. Lactating and nonlactating cyclic female rats were given an estradiol-containing capsule after ovariectomy, and blood samples were collected through an indwelling catheter for serum LH determinations. In lactating, freely suckled ovariectomized rats, estrogen treatment induced an afternoon LH surge with a magnitude and timing comparable to those seen in nonlactating rats. Removal of pups from the lactating rats at 0900, 1100, or 1300 h, but not at 1500 h, suppressed the estrogen-induced surge that normally occurs in the afternoon of the same day. The suppressive effect of pup removal at 0900 h was completely abolished when the pups were returned by 1400 h. In contrast, pup removal was ineffective in abolishing the stimulatory effect of progesterone on LH surges. Double immunohistochemical staining for gonadotropin-releasing hormone (GnRH) and c-Fos, a marker for neuronal activation, revealed a decrease, concomitantly with the suppression of LH surges, in the number of c-Fos-immunoreactive GnRH neurons in the preoptic regions of nonsuckled rats. An LH surge was restored in nonsuckled rats when 0.1 microg oxytocin was injected into the third ventricle three times at 1-h intervals during pup removal. These results suggest that the GnRH surge generator of lactating rats requires the suckling stimulus that is not involved in nonlactating cyclic female rats.
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Affiliation(s)
- Atsushi Fukushima
- Department of Physiology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi 409-3898, Japan
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Mitsui T, Sugiyama N, Maeda S, Tohyama C, Arita J. Perinatal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin suppresses contextual fear conditioning-accompanied activation of cyclic AMP response element-binding protein in the hippocampal CA1 region of male rats. Neurosci Lett 2006; 398:206-10. [PMID: 16442728 DOI: 10.1016/j.neulet.2005.12.087] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2005] [Revised: 12/29/2005] [Accepted: 12/29/2005] [Indexed: 10/25/2022]
Abstract
We investigated the effect of in utero and lactational exposures to dioxin on adult offspring with contextual fear conditioning, a sex- and hippocampus-dependent learning paradigm; and we measured the conditioning-accompanied activation of cyclic AMP response element-binding protein (CREB) in the hippocampal CA1 region. Pregnant rats were treated with a low dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on gestation day 15. TCDD treatment decreased freezing time in conditioning tests of adult male offspring but not of female offspring. A similar, male-specific decrease was observed in the percentage of phosphorylated CREB-immunoreactive neurons in the CA1 region following conditioning in TCDD-treated rats. These results suggest that perinatal TCDD exposure impairs hippocampus-dependent learning in male offspring by suppressing CREB activation.
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Affiliation(s)
- Tetsuo Mitsui
- Department of Physiology, Interdisciplinary Graduate School of Medicine and Engineering, The University of Yamanashi, Yamanashi 409-3898, Japan
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Kudo K, Wati H, Qiao C, Arita J, Kanba S. Age-related disturbance of memory and CREB phosphorylation in CA1 area of hippocampus of rats. Brain Res 2005; 1054:30-7. [PMID: 16054117 DOI: 10.1016/j.brainres.2005.06.045] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2004] [Revised: 05/31/2005] [Accepted: 06/05/2005] [Indexed: 12/22/2022]
Abstract
In the early process of long-term memory formation, cyclic AMP response element-binding protein (CREB), a transcription factor on which multiple signal transduction pathways converge, has been implicated. We examined whether the age difference in the performance of contextual fear conditioning (CFC) is associated with a change in activation of CREB in the hippocampus which is an important neural structure for long-term memory. The activation of CREB in the hippocampus in young (15 weeks old) and old (120 weeks old) male rats was determined immunohistochemically with an antibody that specifically recognizes the phosphorylated form of CREB (pCREB). Young rats exhibited better performance than old rats with respect to the freezing time in CFC. Phosphorylation of CREB as revealed by the ratio of the pCREB-immunoreactive cell number to the CREB-immunoreactive cell number was increased in the CA1 region, but not in other hippocampal regions following training for CFC. The close relationship between behavioral performance and CREB phosphorylation in the CA1 region suggests that hippocampal CREB is involved in age-related decline of learning and memory.
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Affiliation(s)
- Koutaro Kudo
- Department of Neuropsychiatry, Interdisciplinary Graduate School of Medicine and Engineering, Yamanashi University, Yamanashi, Japan
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Arita J, Hasegawa K, Kokudo N, Sano K, Sugawara Y, Makuuchi M. Randomized clinical trial of the effect of a saline-linked radiofrequency coagulator on blood loss during hepatic resection. Br J Surg 2005; 92:954-9. [PMID: 16034832 DOI: 10.1002/bjs.5108] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Use of a saline-linked radiofrequency coagulator (dissecting sealer) has been suggested to reduce blood loss during hepatic resection. A randomized clinical trial was conducted to assess the effects of using the device on the amount of blood loss. METHODS Patients scheduled to undergo hepatic resection were randomly assigned to either use of the dissecting sealer or the clamp crushing method. The primary outcome measure was blood loss during liver parenchymal division. Multivariate analysis was also performed. RESULTS Ninety-four consecutive patients underwent hepatic resection and 40 patients were assigned to each group. There were no significant differences between the dissecting sealer and clamp crushing groups in blood loss during liver parenchymal division (median 373 versus 535 ml; P = 0.252) or total intraoperative blood loss (665 versus 733 ml; P = 0.450). Multivariate analysis revealed that use of the dissecting sealer offered no protection against blood loss compared with the clamp crushing method (odds ratio 1.17 (95 per cent confidence interval 0.39 to 3.53); P = 0.777), whereas number of resections, thoracotomy and type of resection had a significant effect. CONCLUSION Use of a dissecting sealer offered no substantial benefit over the clamp crushing method in reducing blood loss during hepatic resection.
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Affiliation(s)
- J Arita
- Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
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Abstract
We propose a wearable pointing device using EMG signals. By using neural networks, the system adapts to variations in EMG signals caused by individual differences of muscular features and minor shifts in electrode sites. Experimental results show that the system, which frees the operator from having to be in front of a computer, is effective as a pointing device for a wearable computer.
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Kudo K, Qiao CX, Kanba S, Arita J. A selective increase in phosphorylation of cyclic AMP response element-binding protein in hippocampal CA1 region of male, but not female, rats following contextual fear and passive avoidance conditioning. Brain Res 2005; 1024:233-43. [PMID: 15451386 DOI: 10.1016/j.brainres.2004.08.007] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2004] [Indexed: 11/30/2022]
Abstract
Cyclic AMP response element-binding protein (CREB), a transcription factor on which multiple signal transduction pathways converge, has been implicated in long-term memory. We examined whether the sex difference in the performance of contextual fear or passive avoidance conditioning is associated with a change in the activation of CREB in the hippocampus, a neural structure important for long-term memory. The activation of CREB in different subregions within the hippocampus in male and female rats was determined immunohistochemically with an antibody that specifically recognizes the phosphorylated form of CREB (pCREB). With respect to the freezing time in contextual fear conditioning and the step-through latency in passive avoidance conditioning, male rats exhibited better performance than female rats. Phosphorylation of CREB (% pCREB) as revealed by the ratio of the pCREB-immunoreactive (pCREB-ir) cell number to the CREB-immunoreactive cell number was increased in the CA1 region, but not in CA3, CA4, or in the dentate gyrus following training for both types of conditioning in males. In females, such an increase in % pCREB was not found in any hippocampal subregion at any time after conditioning or by increasing the intensity of foot shock. Orchidectomy in males did not alter either the performance of contextual conditioning or conditioning-induced CREB phosphorylation in CA1. The close relationship between behavioral performance and CREB phosphorylation in the CA1 region suggests that hippocampal CREB is involved in the sex difference in some forms of learning and memory.
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Affiliation(s)
- Koutarou Kudo
- Department of Neuropsychiatry, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Tamaho, Yamanashi 409-3898, Japan
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Arita J. [Analysis of the secretory volume at a single cell level]. Nihon Seirigaku Zasshi 2005; 67:241-50. [PMID: 16119828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
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Yamakawa K, Arita J. Cross-talk between the estrogen receptor-, protein kinase A-, and mitogen-activated protein kinase-mediated signaling pathways in the regulation of lactotroph proliferation in primary culture. J Steroid Biochem Mol Biol 2004; 88:123-30. [PMID: 15084344 DOI: 10.1016/j.jsbmb.2003.11.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2003] [Accepted: 11/13/2003] [Indexed: 11/30/2022]
Abstract
Using pharmacological means we investigated the functional interactions between the estrogen receptor (ER)-, protein kinase A (PKA)-, and mitogen-activating protein kinase (MAPK)-mediated pathways in the regulation of lactotroph proliferation in primary culture. Treatment of lactotrophs for 28 h with the PKA inhibitor H89 or KT5720, an effective inhibitor of forskolin-induced proliferation, inhibited both insulin- and estradiol-induced proliferation. Inhibition of the MAPK activity by PD98059 or U0126 suppressed not only insulin-induced proliferation but also forskolin- and estradiol-induced proliferation. However, treatment for 28 h with the antiestrogens 4-hydroxy tamoxifen and ICI182780 failed to antagonize estradiol-induced lactotroph proliferation but instead enhanced it. Prolonging the antiestrogen treatment time from 28 to 88 h was effective in antagonizing estradiol-induced proliferation with this long-term treatment also inhibiting insulin- and forskolin-induced proliferation. There was no decrease in these mitogen-induced proliferations following treatment with a progesterone antagonist or protein kinase C inhibitor. These results suggest that cross-talk occurs between the ER-, PKA-, and MAPK-mediated signaling pathways in the regulation of lactotroph proliferation, and that antiestrogens stimulate and inhibit estradiol-induced proliferation in a time-dependent manner.
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Affiliation(s)
- Koji Yamakawa
- Department of Physiology, University of Yamanashi Interdisciplinary Graduate School of Medicine and Engineering, Tamaho, Nakakoma, Yamanashi 409-3898, Japan
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Sugiyama N, Kanba S, Arita J. Temporal changes in the expression of brain-derived neurotrophic factor mRNA in the ventromedial nucleus of the hypothalamus of the developing rat brain. Brain Res Mol Brain Res 2003; 115:69-77. [PMID: 12824057 DOI: 10.1016/s0169-328x(03)00184-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family, which is important for the growth, differentiation, and survival of neurons during development. We have performed a detailed mapping of BDNF mRNA in the neonatal rat brain using a quantitative in situ hybridization technique. At postnatal day (PND) 4, hypothalamic structures showed only modest expression of BDNF mRNA, with the exception of the ventromedial nucleus (VMN), where expression was higher than that detected in the hippocampus. Abundant BDNF mRNA was also found in the bed nucleus of the anterior commissure, retrosplenial granular cortex, and the posteroventral part of the medial amygdaloid nucleus. Messenger RNAs encoding other neurotrophins, including nerve growth factor (NGF) and neurotrophin-3 (NT-3) and the BDNF receptor trkB, were not selectively localized in neonatal VMN. During subsequent developmental stages, BDNF mRNA expression in the VMN changed dynamically, peaking at PND 4 and falling to minimal levels in the adult brain. In contrast, the low levels of BDNF mRNA observed in the CA3 region of the hippocampus increased to adult levels following PND 10. As the VMN undergoes sexual differentiation, we compared BDNF, NGF, NT-3, and trkB mRNA expression in the VMN in males and females at embryonic day 20 and PND 4, but found no differences between them. These results suggest that localized and high level expression of BDNF mRNA in the neonatal VMN plays an important role in its neural organization and functional development.
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Affiliation(s)
- Nobuhiro Sugiyama
- Department of Neuropsychiatry, University of Yamanashi Faculty of Medicine, Tamaho, Yamanashi 409-3898, Japan
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Horiuchi J, Saigusa T, Sugiyama N, Kanba S, Nishida Y, Sato Y, Hinuma S, Arita J. Effects of prolactin-releasing peptide microinjection into the ventrolateral medulla on arterial pressure and sympathetic activity in rats. Brain Res 2002; 958:201-9. [PMID: 12468046 DOI: 10.1016/s0006-8993(02)03718-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Prolactin-releasing peptide (PrRP), originally isolated from the hypothalamus, is highly localized in the cardiovascular regions of the medulla, and intracerebroventricular administration of PrRP causes a pressor response. In the present study we investigated the cardiovascular effects of PrRP applied to functionally different areas of the ventrolateral medulla (VLM), and to the nucleus tractus solitarius (NTS) and the area postrema (AP). In urethane-anesthetized rats, microinjection of PrRP into the pressor area of the most caudal VLM, recognized as the caudal pressor area in the rat, elicited dose-dependent increases in mean arterial pressure, heart rate, and renal sympathetic nerve activity. In the same injection area, neither thyrotropin-releasing hormone, corticotropin-releasing hormone nor angiotensin II affected these baseline cardiovascular variables. On the other hand, microinjection of PrRP into more rostral parts of the VLM, i.e. the depressor area of the caudal VLM and the pressor area of the rostral VLM, as well as the NTS and the AP, had no effect on these cardiovascular variables. Immunohistochemical analysis in the medulla revealed that the cardiovascularly PrRP-responsive region contained PrRP-immunoreactive cell bodies and nerve fibers. These results suggest that the most caudal VLM is an action site of PrRP to induce a pressor response, which is mediated, at least partly, by the increase in sympathetic outflow.
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Affiliation(s)
- Jouji Horiuchi
- Department of Physiology, The National Defense Medical College, Tokorozawa, 359-8513, Saitama, Japan
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Abstract
Estrogen affects apoptotic cell death in estrogen-responsive tissues. The purpose of the present study was to examine dynamic changes in apoptotic cell death in the anterior pituitary gland during the estrous cycle and to investigate neuroendocrine regulation of these changes in cycling female rats. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) for in situ detection of DNA strand breaks revealed that the number of TUNEL-positive anterior pituitary cells was changing during the estrous cycle, with a maximum in the morning of proestrus and a minimum in the morning of estrus. A similar pattern was observed with Bax immunostaining; however, no difference was observed in Bcl-2 immunostaining. Most of Bax-immunoreactive cells were identified as a subpopulation of gonadotropes. Pentobarbital administered in the afternoon of proestrus attenuated the decrease in TUNEL-positive or Bax-immunoreactive cells in the morning of estrus, although estradiol treatment failed to affect it. This action of pentobarbital was reduced by simultaneous treatment with an ovulation-inducing dose of gonadotropin-releasing hormone (GnRH), but not with progesterone, an ovarian steroid also released after GnRH treatment. These results suggest that anterior pituitary cells, mostly gonadotropes, undergo a cyclic change in apoptotic cell death during the estrous cycle and that the inhibition of apoptosis on estrus is due, at least in part, to the proestrous surge of GnRH secretion.
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Affiliation(s)
- Ping Yin
- Department of Physiology, Yamanashi Medical University, Yamanashi, Japan
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Kawashima K, Yamakawa K, Takahashi W, Takizawa S, Yin P, Sugiyama N, Kanba S, Arita J. The estrogen-occupied estrogen receptor functions as a negative regulator to inhibit cell proliferation induced by insulin/IGF-1: a cell context-specific antimitogenic action of estradiol on rat lactotrophs in culture. Endocrinology 2002; 143:2750-8. [PMID: 12072410 DOI: 10.1210/endo.143.7.8915] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Estrogens stimulate cell proliferation in typical estrogen-responsive tissues including the anterior pituitary gland. Here we report that 17-beta estradiol (E2) has estrogen receptor-mediated mitogenic and antimitogenic actions on rat lactotrophs in primary culture, depending on the cell context. E2 did not affect basal proliferation at 2 d after treatment, but it increased it at 4 d. Insulin markedly increased proliferative activity, which was inhibited by simultaneous treatment with E2, even after only 2 d of treatment. This antimitogenic action on insulin-induced proliferation was also observed with other estrogens but not with nonestrogenic steroids. Treatment with antiestrogens in combination with E2 antagonized both the mitogenic and antimitogenic actions of E2. Antiestrogen treatment alone inhibited basal proliferation, and it mimicked the inhibitory action of E2 on insulin-induced proliferation with less potency. In parallel with cell proliferation, an insulin-induced increase in the cell number of cyclin D1-immunoreactive lactotrophs was inhibited by E2 treatment. Although the antimitogenic action of E2 was seen with a wide range of doses of insulin or IGF-1, proliferation was stimulated rather than inhibited by E2 when cells were treated with serum or forskolin/isobutylmethylxanthine instead of insulin, indicating a mitogen-specific, but not proliferative activity-dependent, inhibition by E2. The results of estrogen-occupied estrogen receptors as negative regulators of proliferation suggest a novel interaction between estrogen and growth factors in the regulation of proliferation in estrogen-responsive cells.
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Affiliation(s)
- Kengo Kawashima
- Department of Physiology, Yamanashi Medical University, Japan
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40
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Yin P, Kawashima K, Arita J. Direct actions of estradiol on the anterior pituitary gland are required for hypothalamus-dependent lactotrope proliferation and secretory surges of luteinizing hormone but not of prolactin in female rats. Neuroendocrinology 2002; 75:392-401. [PMID: 12065892 DOI: 10.1159/000059436] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Estradiol induces surges of prolactin (PRL) and luteinizing hormone (LH) secretion as well as lactotrope proliferation in female rats. We examined whether these hypothalamus-dependent events require the direct action of estradiol on the anterior pituitary gland by selective blockade of its peripheral actions, using ICI182,780 (ICI), an antiestrogen that cannot cross the blood-brain barrier. Injection of ICI into ovariectomized rats, at a dose of 250 microg/day for 4 days, almost completely inhibited estradiol-induced growth of the uterus, proliferation of lactotropes as determined by bromodeoxyuridine incorporation, and afternoon surges of LH secretion. However, ICI only partially inhibited estradiol-induced surges of PRL secretion and had no effect on estradiol-induced tonic inhibition of LH secretion even at the highest dose of 1,000 microg/day. The inhibitory effects of ICI found at 250 microg/day were attributable to its selective peripheral, but not central actions since ICI did not alter hypothalamic expression of progesterone receptors, an estradiol-dependent brain process. Estradiol-induced increases in the number of progesterone receptor-immunoreactive cells in the hypothalamic ventromedial nucleus and the medial preoptic area were not inhibited by this dose of ICI but were inhibited by 500 microg/day tamoxifen, an antiestrogen that can cross the blood-brain barrier. Treatment of cycling female rats with 250 microg/day ICI beginning from diestrus day 2 was also effective in blocking estrous lactotrope proliferation and preovulatory surges of LH secretion but not PRL secretion. Finally, in ovariectomized estradiol-treated pup-deprived lactating rats, ICI did not affect suckling-induced PRL secretion but completely blocked lactotrope proliferation. These results suggest that a direct estradiol action on the anterior pituitary gland is required for lactotrope proliferation and the positive feedback action on LH secretion but not for the secretory surges of PRL or for negative feedback.
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Affiliation(s)
- Ping Yin
- Department of Physiology, Yamanashi Medical University, Yamanashi, Japan
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Arita J, Matsushima H, Eto Y, Morikawa T. [Band heterotopia in a male patient with Lennox-Gastaut syndrome]. No To Hattatsu 2001; 33:533-6. [PMID: 11725523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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Abstract
Water extracts from the brackishwater clam (Corbicula japonica) are lethal to mice upon i.v. injection. Further mouse assays confirmed that the toxicity exhibits a regional variation but no seasonal or sexual variations. The C. japonica toxin was purified from foot muscle, the most toxic tissue, successively by hydrophobic chromatography on Phenyl Sepharose, gel filtration on Sephacryl S-200, hydrophobic FPLC on Phenyl Superose and cation-exchange FPLC on Mono S. The purified toxin had an i.v. LD50 of 11 microg/kg against mice. It was a weakly basic protein (pI 7.7) with a mol. wt of 23,000 and was rich in Gly, Glx and Asx but devoid of Met. Analysis of the purified toxin by a protein sequencer afforded no N-terminal amino acid. In addition to C. japonica, two species of freshwater clams belonging to the genus Corbicula, C. leana and C. sandai, were newly found to be toxic, although much less potent than C. japonica. Despite the difference in anatomical distribution of toxins among the three species of Corbicula clams, both C. leana and C. sandai toxins were closely similar in stability and mol. wt to the C. japonica toxin.
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Affiliation(s)
- J Arita
- Department of Food Science and Technology, Tokyo University of Fisheries, Konan-4, Minato-ku, 108-8477, Tokyo, Japan
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Kawashima K, Yamakawa K, Arita J. Involvement of phosphoinositide-3-kinase and p70 S6 kinase in regulation of proliferation of rat lactotrophs in culture. Endocrine 2000; 13:385-92. [PMID: 11216652 DOI: 10.1385/endo:13:3:385] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2000] [Revised: 07/31/2000] [Accepted: 08/07/2000] [Indexed: 01/02/2023]
Abstract
Phosphoinositide-3-kinase (PI-3K) and p70 S6 kinase (p70S6k) are suggested as important molecules for mediating mitogenic actions of growth factors and cytokines in a variety of cell types. The purpose of the present study was to investigate whether these kinases were involved in mediation of the mitogenic actions of not only the growth factor insulin but also cyclic adenosine monophosphate (cAMP) and estrogen on rat cultured lactotrophs. Treatment with wortmannin or LY294002, a PI-3K inhibitor, or rapamycin, a p70S6k inhibitor, decreased basal levels of 5-bromo-2-deoxyuridine (BrdU)-labeling indices of lactotrophs in a dose-dependent manner. These inhibitors were effective in blocking an increase in BrdU-labeling indices induced by insulin. LY294002 and rapamycin also suppressed an increase in BrdU-labeling indices induced by forskolin, an adenylate cyclase activator, or dibutyryl cAMP, a membrane-permeable cAMP analog, as well as that induced by estradiol, a physiologic extracellular activator of lactotroph proliferation. However, the dibutyryl cAMP-, but not insulin-induced proliferation, acquired a resistance to LY294002 and rapamycin by pretreatment with bromocriptine, a dopaminergic agonist that is able to suppress lactotroph proliferation. These results suggest that the mitogenic actions of cAMP and estradiol on rat lactotrophs are mediated by PI-3K and p70S6k, and that dopaminergic inhibition modifies the PI-3K and p70S6k dependence of the regulation of lactotroph proliferation.
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Affiliation(s)
- K Kawashima
- Department of Physiology, Yamanashi Medical University, Tamaho, Japan
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Abstract
The proestrous surge of prolactin (PRL) secretion and subsequent proliferation of lactotropes at estrus have been suggested to be induced by a common hypothalamic hormone. We investigated changes in lactotrope proliferation at other reproductive stages of female rats when PRL secretion was stimulated. To assess proliferative activity of lactotropes, incorporation of 5-bromo-2'-deoxyuridine (BrdU) into DNA was measured by double immunostaining for PRL and BrdU. BrdU-labeling indices, determined by BrdU injections at 10.00 h, revealed low levels of proliferative activity of lactotropes at the reproductive stages including diestrus, days 6 and 13 of pregnancy, and day 6 of lactation while high levels were detected on estrus and the day of parturition. When BrdU-labeling indices were determined at 3-hour intervals through day 6 of pregnancy to find an increase in lactotrope proliferation which might occur at times other than 10.00 h, proliferative activity of lactotropes remained at low levels with a slight increase in the afternoon. Such a diurnal change as observed in early pregnancy was not detected on day 13 of pregnancy. In contrast, short-interval determinations of BrdU-labeling indices during a period from day 20 of pregnancy to day 2 of lactation revealed a marked increase in proliferative activity on the day of parturition with a peak at 18.00 h, which was comparable to that observed at estrus. To investigate involvement of ovarian steroids in suppression of lactotrope proliferation as observed during early pregnancy and lactation, ovariectomized and pup-removed lactating rats were given one of treatment combinations of estradiol and suckling. In pup-removed lactating rats, estradiol treatment alone induced neither a PRL surge nor an increase in BrdU-labeling indices. Suckling stimuli, which were effective in increasing serum PRL concentrations irrespective of estradiol treatment, elicited a marked increase in BrdU-labeling indices in the presence of estradiol but not in its absence. These results suggest that proliferative activity of rat lactotropes does not necessarily correlate with PRL secretion during pregnancy and lactation. In contrast to PRL release, lactotrope proliferation requires both a hypophysiotropic stimulatory input from the hypothalamus and a sensitizing action of estradiol, an observation which may account for the fact that proliferation does not occur during pregnancy and lactation in spite of elevated PRL release.
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Affiliation(s)
- P Yin
- Department of Physiology, Yamanashi Medical University, Yamanashi, Japan
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Arita J, Maekawa K, Matsushima H, Eto Y, Harada T, Hano H, Morikawa T. [A patient with epilepsy, congenital alopecia and mental retardation: combination of atypical absence in waking and nocturnal partial seizure]. No To Hattatsu 2000; 32:312-7. [PMID: 10916370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
We report a 7-year-old girl with epilepsy, congenital alopecia, and mental retardation. She was hairless at birth. Very scanty hair, eyebrows and eyelashes appeared at 2 years of age. Developmental delay was first recognized at 6 years. Nocturnal partial seizures occurred at 4 years, and atypical absence in waking at 6 years. Electroencephalogram showed spike-waves in the centrotemporal area which increased and developed into a generalized continuous spike and wave complexes upon sleeping at the age of 7 years 1 month. Ictal electroencephalogram in atypical absence showed generalized 3 c/s spike and wave complexes. Skin biopsy of the scalp showed scanty, immature hair follicles and immature sebaceous glands. Whether this case is related to ectodermal dysplasia is unclear.
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Affiliation(s)
- J Arita
- Department of Pediatrics, Jikei University School of Medicine, Tokyo
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Nara T, Hamano S, Nozaki H, Tanaka Y, Shimizu M, Noda Y, Atsukawa K, Arita J, Horita H, Maekawa K. [Epileptogenesis of acute encephalitis and acute encephalopathy: epilepsy with its onset in the acute phase and without a latent period]. No To Hattatsu 2000; 32:261-7. [PMID: 10824579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Epileptogenesis was evaluated in 60 patients with acute encephalitis and in 10 patients with acute encephalopathy. Forty-seven patients have been seizure-free during for more than three years' follow-up (Group III). On the other hand, 23 patients developed epilepsy. Among them, 18 patients developed epilepsy after a latent period of 1 month to 2 3/12 years (Group I). In Group I, a younger age of the onset, a long period of disturbed consciousness and a high activity of CSF neuron-specific enolase (NSE) was associated with refractory epilepsy. The other five patients had continuous seizures from the acute phase of encephalitis without a latent period (Group II). They had more than 2 types of partial motor seizures which occurred frequently during the acute phase of encephalitis. The NSE activity in the CSF of patients in Group II was less than 50 ng/ml, being similar to those in Group III. The epilepsy in Group II, however, was the most refractory. The reason for the development of this continuous refractory epilepsy remained obscure.
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Affiliation(s)
- T Nara
- Division of Neurology, Saitama Children's Medical Center
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Hashimoto M, Kuroshima A, Arita J, Shibata M. Brown fat temperature decrease by electrical stimulation of in and around retrorubral field in the golden hamster. J Therm Biol 1999. [DOI: 10.1016/s0306-4565(99)00056-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Suzuki S, Yamamoto I, Arita J. Mitogen-activated protein kinase-dependent stimulation of proliferation of rat lactotrophs in culture by 3',5'-cyclic adenosine monophosphate. Endocrinology 1999; 140:2850-8. [PMID: 10342877 DOI: 10.1210/endo.140.6.6775] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Intracellular cAMP regulates cell proliferation as a second messenger of extracellular signals in a number of cell types. We investigated, by pharmacological means, whether an increase in intracellular cAMP levels changes proliferation rates of lactotrophs in primary culture, whether there are interactions between signal transduction pathways of cAMP and the growth factor insulin, and where the dopamine receptor agonist bromocriptine acts in the cAMP pathway to inhibit lactotroph proliferation. Rat anterior pituitary cells, cultured in serum-free medium, were treated with cAMP-increasing agents, followed by 5-bromo-2'-deoxyuridine (BrdU) to label proliferating pituitary cells. BrdU-labeling indices indicative of the proliferation rate of lactotrophs were determined by double immunofluorescence staining for PRL and BrdU. Treatment with forskolin (an adenylate cyclase activator) or (Bu)2cAMP (a membrane-permeable cAMP analog) increased BrdU-labeling indices of lactotrophs in a dose- and incubation time-dependent manner. The cAMP-increasing agents were also effective in increasing BrdU-labeling indices in populations enriched for lactotrophs by differential sedimentation. The stimulatory action of forskolin was observed, regardless of concentrations of insulin that were added in combination with forskolin. Inhibition of the action of endogenous cAMP by H89 or KT5720, a protein kinase A inhibitor, attenuated an increase in BrdU-labeling indices by insulin treatment. On the other hand, the specific mitogen-activated protein kinase inhibitor PD98059, which was effective in blocking the mitogenic action of insulin, markedly suppressed the forskolin-induced increase in BrdU-labeling indices. (Bu)2cAMP antagonized not only inhibition of BrdU labeling indices but also changes in cell shape induced by bromocriptine treatment, although forskolin did not have such an antagonizing effect. These results suggest that: 1) intracellular cAMP plays a stimulatory role in the regulation of lactotroph proliferation; 2) cAMP and insulin/mitogen-activated protein kinase signalings require each other for their mitogenic actions; and 3) the antimitogenic action of bromocriptine is, at least in part, caused by inhibition of cAMP production.
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Affiliation(s)
- S Suzuki
- Department of Physiology, Yamanashi Medical University, Japan
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Abstract
A newly identified hypothalamic peptide whose specific receptors are present in the anterior pituitary gland is a selective and potent stimulator of prolactin secretion and is therefore termed prolactin-releasing peptide (PRP). We investigated the distribution of PRP-containing neurons in the hypothalamus of female rats by immunocytochemical techniques. Immunocytochemistry using a specific antibody raised to PRP revealed that PRP-immunoreactive perikarya were located in the posteroventral part of the dorsomedial nucleus of the hypothalamus. PRP-immunoreactive nerve terminals were present in high concentrations in a region ventral to the bed nucleus of the stria terminalis, but scarcely observed in the external layer of the median eminence in which well known hypothalamic hormones such as growth hormone-releasing hormone and somatostatin were abundantly detected. This specific distribution in the hypothalamus suggests a novel route of the hypophysiotropic action of PRP.
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Affiliation(s)
- K Yamakawa
- Department of Physiology, Yamanashi Medical University, Japan
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Izaki Y, Hashimoto M, Arita J. Enhancement by 1-oleoyl-2-docosahexaenoyl phosphatidylcholine of long-term potentiation in the rat hippocampal CA1 region. Neurosci Lett 1999; 260:146-8. [PMID: 10025720 DOI: 10.1016/s0304-3940(98)00965-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We reported previously that administration of 1-oleoyl-2-docosahexaenoyl-sn-glycero-3-phosphorylcholine (ODHPC), a kind of phosphatidylcholine, enhanced discriminatory shock avoidance learning in rats. Since long-term potentiation (LTP) of the hippocampus has been suggested to be a physiological substrate of some forms of memory, we investigated the effects of ODHPC on LTP in the rat hippocampal CA1 region. LTP in the amplitude of population spikes in the CA1 region was induced by tetanic stimulation in anesthetized rats. ODHPC significantly increased magnitudes of LTP in a dose-dependent manner when injected intraperitoneally 20 min before inducing LTP. However, administration of 1,2-dioleoyl-sn-glycero-3-phosphorylcholine, in which only docosahexaenoyl residue of ODHPC was replaced with oleoyl residue, did not affect LTP. These results suggest that ODHPC enhances hippocampal LTP by its specific conformation.
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Affiliation(s)
- Y Izaki
- Department of Physiology, Saitama Medical University, Japan
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