1
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Barooni AB, Ghorbani M, Salimi V, Alimohammadi A, Khamseh ME, Akbari H, Imani M, Nourbakhsh M, Sheikhi A, Shirian FI, Ameri M, Tavakoli-Yaraki M. Up-regulation of 15-lipoxygenase enzymes and products in functional and non-functional pituitary adenomas. Lipids Health Dis 2019; 18:152. [PMID: 31288808 PMCID: PMC6617742 DOI: 10.1186/s12944-019-1089-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 06/13/2019] [Indexed: 12/24/2022] Open
Abstract
Background Pituitary adenoma accounts as a complex and multifactorial intracranial neoplasm with wide range of clinical symptoms which its underlying molecular mechanism has yet to be determined. The bioactive lipid mediators received attentions toward their contribution in cancer cell proliferation, progression and death. Amongst, 15-Lipoxygense (15-Lox) enzymes and products display appealing role in cancer pathogenesis which their possible effect in pituitary adenoma tumor genesis is perused in the current study. Methods The 15-Lipoxygenses isoforms expression level was evaluated in tumor tissues of prevalent functional and non-functional pituitary adenomas and normal pituitary tissues via Real-Time PCR. The circulating levels of 15(S) HETE and 13(S) HODE as 15-Lox main products were assessed in serum of patients and healthy subjects using enzyme immunoassay kits. Results Our results revealed that 15-Lox-1 and 15-Lox-2 expression levels were elevated in tumor tissues of pituitary adenomas comparing to normal pituitary tissues. The elevated levels of both isoforms were accompanied with 15(S) HETE and 13(S) HODE elevation in the serum of patients. The 15-Lox-1 expression and activity was higher in invasive tumors as well as tumors with bigger size indicating the possible pro-tumorigenic role of 15-Lox-1, more than 15-Lox-2 in pituitary adenomas. The diagnostic value of 15-Lipoxygense isoforms and products were considerable between patients and healthy groups. Conclusion The possible involvement of 15-Lipoxygense pathway especially 15-Lox-1 in the regulation of pituitary tumor growth and progression may open up new molecular mechanism regarding pituitary adenoma pathogenesis and might shed light on its new therapeutic strategies.
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Affiliation(s)
- Alaleh Bayat Barooni
- Department of Biochemistry, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Ghorbani
- Division of Vascular and Endovascular Neurosurgery, Firoozgar Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Vahid Salimi
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Mohammad E Khamseh
- Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences (IUMS), Tehran, Iran
| | - Hamideh Akbari
- Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences (IUMS), Tehran, Iran.,Clinical Research Development Unit (CRDU), Sayad Shirazi Hospital, Golestan University of Medical Sciences, Gorgan, Iran
| | - Mehrnaz Imani
- Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences (IUMS), Tehran, Iran
| | - Mitra Nourbakhsh
- Department of Biochemistry, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Alireza Sheikhi
- Department of Biochemistry, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Farzad Izak Shirian
- Department of Biochemistry, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Maryam Ameri
- Forensic Medicine Department, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Masoumeh Tavakoli-Yaraki
- Department of Biochemistry, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
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2
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Wu Y, Zhang Y, Hou Z, Fan G, Pi J, Sun S, Chen J, Liu H, Du X, Shen J, Hu G, Chen W, Pan A, Yin P, Chen X, Pu Y, Zhang H, Liang Z, Jian J, Zhang H, Wu B, Sun J, Chen J, Tao H, Yang T, Xiao H, Yang H, Zheng C, Bai M, Fang X, Burt DW, Wang W, Li Q, Xu X, Li C, Yang H, Wang J, Yang N, Liu X, Du J. Population genomic data reveal genes related to important traits of quail. Gigascience 2018; 7:4995262. [PMID: 29762663 PMCID: PMC5961004 DOI: 10.1093/gigascience/giy049] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 04/27/2018] [Indexed: 12/18/2022] Open
Abstract
Background Japanese quail (Coturnix japonica), a recently domesticated poultry species, is important not only as an agricultural product, but also as a model bird species for genetic research. However, most of the biological questions concerning genomics, phylogenetics, and genetics of some important economic traits have not been answered. It is thus necessary to complete a high-quality genome sequence as well as a series of comparative genomics, evolution, and functional studies. Results Here, we present a quail genome assembly spanning 1.04 Gb with 86.63% of sequences anchored to 30 chromosomes (28 autosomes and 2 sex chromosomes Z/W). Our genomic data have resolved the long-term debate of phylogeny among Perdicinae (Japanese quail), Meleagridinae (turkey), and Phasianinae (chicken). Comparative genomics and functional genomic data found that four candidate genes involved in early maturation had experienced positive selection, and one of them encodes follicle stimulating hormone beta (FSHβ), which is correlated with different FSHβ levels in quail and chicken. We re-sequenced 31 quails (10 wild, 11 egg-type, and 10 meat-type) and identified 18 and 26 candidate selective sweep regions in the egg-type and meat-type lines, respectively. That only one of them is shared between egg-type and meat-type lines suggests that they were subject to an independent selection. We also detected a haplotype on chromosome Z, which was closely linked with maroon/yellow plumage in quail using population resequencing and a genome-wide association study. This haplotype block will be useful for quail breeding programs. Conclusions This study provided a high-quality quail reference genome, identified quail-specific genes, and resolved quail phylogeny. We have identified genes related to quail early maturation and a marker for plumage color, which is significant for quail breeding. These results will facilitate biological discovery in quails and help us elucidate the evolutionary processes within the Phasianidae family.
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Affiliation(s)
- Yan Wu
- Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Science, Wuhan 430064, China.,Key Laboratory of Animal Embryo Engineering and Molecular Breeding of Hubei Province,Wuhan 430064, China.,Hubei Innovation Center of Agricultural Science and Technology, Wuhan, Hubei, 430064, China
| | - Yaolei Zhang
- BGI-Shenzhen, Shenzhen 518083, China.,BGI-Qingdao, BGI-Shenzhen, Qingdao, 266555, China.,China National GeneBank-Shenzhen, BGI-Shenzhen, Shenzhen 518083, China
| | - Zhuocheng Hou
- National Engineering Laboratory for Animal Breeding and MOA Key Laboratory of Animal Genetics and Breeding, China; Agricultural University, Beijing 100193, China
| | - Guangyi Fan
- BGI-Shenzhen, Shenzhen 518083, China.,BGI-Qingdao, BGI-Shenzhen, Qingdao, 266555, China.,State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, Macao, China.,China National GeneBank-Shenzhen, BGI-Shenzhen, Shenzhen 518083, China
| | - Jinsong Pi
- Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Science, Wuhan 430064, China
| | - Shuai Sun
- BGI-Qingdao, BGI-Shenzhen, Qingdao, 266555, China
| | - Jiang Chen
- BGI-Shenzhen, Shenzhen 518083, China.,China National GeneBank-Shenzhen, BGI-Shenzhen, Shenzhen 518083, China
| | - Huaqiao Liu
- Hubei Shendan Healthy Food Co., Ltd., Wuhan 430206, China
| | - Xiao Du
- BGI-Qingdao, BGI-Shenzhen, Qingdao, 266555, China
| | - Jie Shen
- Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Science, Wuhan 430064, China
| | - Gang Hu
- BGI-Qingdao, BGI-Shenzhen, Qingdao, 266555, China
| | | | - Ailuan Pan
- Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Science, Wuhan 430064, China
| | - Pingping Yin
- BGI-Qingdao, BGI-Shenzhen, Qingdao, 266555, China
| | | | - Yuejin Pu
- Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Science, Wuhan 430064, China
| | - He Zhang
- BGI-Shenzhen, Shenzhen 518083, China
| | - Zhenhua Liang
- Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Science, Wuhan 430064, China
| | | | - Hao Zhang
- Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Science, Wuhan 430064, China
| | - Bin Wu
- BGI-Shenzhen, Shenzhen 518083, China
| | - Jing Sun
- Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Science, Wuhan 430064, China
| | | | - Hu Tao
- Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Science, Wuhan 430064, China
| | - Ting Yang
- BGI-Shenzhen, Shenzhen 518083, China
| | - Hongwei Xiao
- Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Science, Wuhan 430064, China
| | - Huan Yang
- BGI-Shenzhen, Shenzhen 518083, China
| | - Chuanwei Zheng
- Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Science, Wuhan 430064, China
| | | | | | - David W Burt
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, UK
| | - Wen Wang
- Kunming Institute of Zoology, Chinese Academy of Sciences (CAS), Kunming, China
| | - Qingyi Li
- BGI-Qingdao, BGI-Shenzhen, Qingdao, 266555, China
| | - Xun Xu
- BGI-Shenzhen, Shenzhen 518083, China.,China National GeneBank-Shenzhen, BGI-Shenzhen, Shenzhen 518083, China
| | - Chengfeng Li
- BGI-Qingdao, BGI-Shenzhen, Qingdao, 266555, China
| | - Huanming Yang
- BGI-Shenzhen, Shenzhen 518083, China.,James D. Watson Institute of Genome Sciences, Hangzhou 310058, China
| | - Jian Wang
- BGI-Shenzhen, Shenzhen 518083, China.,James D. Watson Institute of Genome Sciences, Hangzhou 310058, China
| | - Ning Yang
- National Engineering Laboratory for Animal Breeding and MOA Key Laboratory of Animal Genetics and Breeding, China; Agricultural University, Beijing 100193, China
| | - Xin Liu
- BGI-Shenzhen, Shenzhen 518083, China.,China National GeneBank-Shenzhen, BGI-Shenzhen, Shenzhen 518083, China
| | - Jinping Du
- Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Science, Wuhan 430064, China
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3
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Limor R, Naor Z, Weisinger G, Naidich M, Knoll E, Sharon O, Stern N. Gonadotropin-releasing hormone activates the 12-lipoxygenase pathway in the LbetaT2 gonadotrope cell line. Neuroendocrinology 2003; 77:291-7. [PMID: 12806174 DOI: 10.1159/000070895] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2002] [Accepted: 03/27/2003] [Indexed: 11/19/2022]
Abstract
Previous studies have indicated that arachidonic acid and its lipoxygenase (LO) metabolites play a role in the post-receptor effects of gonadotropin-releasing hormone (GnRH) but the exact role and nature of these putative eicosanoids remain unclear. The potential role of arachidonic acid and LO in GnRH receptor-mediated signaling was investigated in the LbetaT2 gonadotrope cell line, which expresses gonadotropins (LH and FSH) and GnRH-receptor mRNAs. Western immunobloting of LbetaT2 cell extracts, performed with a murine leukocyte polyclonal antibody against 12-LO, showed a 70-kD band, suggesting the presence of 12-LO protein in these cells. GnRH nearly doubled the release of 12-hydroeicosatetraenoic acid, a product of the 12-LO enzyme, within 10 min. A specific reverse transcriptase polymerase chain reaction with a set of primers based on the reported sequence of rat brain 12-LO yielded a 170-bp band which showed 100% homology with the expected rat brain 12-LO sequence. Exposure of LbetaT2 cells to pulsatile GnRH treatment (10 nM, 90-min interpulse, one and three pulses) led to a approximately 3-fold increase in 12-LO mRNA levels. In conclusion, we provide evidence for the presence of a 12-LO enzyme in LbetaT2 cells, the expression and activity of which are increased by short-term/pulsatile exposure to GnRH. LbetaT2 cells represent a potential model to further study the involvement of 12-LO in GnRH receptor signaling.
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Affiliation(s)
- Rona Limor
- Institute of Endocrinology, Metabolism and Hypertension, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, Tel Aviv, Israel
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4
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Cooke BA. Signal transduction involving cyclic AMP-dependent and cyclic AMP-independent mechanisms in the control of steroidogenesis. Mol Cell Endocrinol 1999; 151:25-35. [PMID: 10411317 DOI: 10.1016/s0303-7207(98)00255-x] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The control of steroidogenesis via signal transduction mechanisms involving cAMP-dependent and cAMP-independent mechanisms is reviewed. Several structurally unrelated factors that are potent stimulators of steroidogenesis whose actions do not require cAMP and/or synthesis of proteins have been identified. These include various interleukins, a lipophilic factor from macrophages, a steroidogenic inducing protein from follicular fluid and an imidazole compound, calmidazolium. All of these factors are capable of inducing maximum steroidogenesis. Calcium is required for steroidogenesis in all steroidogenic cells. With the exception of the effects of angiotensin II, there is little evidence for a role of IP3 in the stimulation of the release of calcium from intracellular stores in steroidogenic cells under physiological conditions. There may however, be a cAMP-mediated activation of a plasma membrane calcium channel. Chloride channels that can be regulated by cAMP-dependent and -independent mechanisms, are present in steroidogenic cells. Chloride ions exert a negative effect on steroidogenesis because exclusion of chloride from the extracellular medium markedly enhances cAMP-stimulated steroidogenesis. Arachidonic acid and its lipoxygenase products are involved in the control of steroidogenesis via cAMP mediated processes. An arachidonic acid related thioesterase has been isolated that is activated by ACTH and which may be involved in the release of arachidonic acid. It is concluded that while cAMP is a second messenger for LH/ACTH in the control of steroidogenesis, other signalling systems exist which are potentially equally effective in controlling steroidogenesis. In addition, the action of cAMP requires other signalling pathways involving calcium and chloride ions, as well as arachidonic acid and its lipoxygenase products.
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Affiliation(s)
- B A Cooke
- Department of Biochemistry and Molecular Biology, Royal Free and University College Medical School, University College London, UK.
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5
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Abstract
The role of fatty acids (FA) as a mediator and modulator of central nervous system activity in general, and peptides in particular, is only recently becoming understood. This paper reviews numerous findings concerned with the activity of fatty acids, particularly with their interaction with diverse neurochemical systems and their consequences for better understanding neurotransmitters, hormones and peptides. The effects include FA as precursors in the manufacture of neurochemical elements, including enzymes, neurotransmitters, and hormones. Of particular interest is the important changes in neuronal membrane composition that have been attributed to FA. Such changes may account for the changes in thermoregulation, learning, and other functions that accompany dietary manipulation of FA intake. While the total level of FA has been the object of many investigations, this report addresses the need to focus on the ratio of FA, especially alpha-linolenic/linoleic acid, which has been shown to be a critical factor in a number of research studies.
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Affiliation(s)
- S Yehuda
- Department of Psychology, Bar-Ilan University, Ramat Gan, Israel.
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6
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Mele PG, Dada LA, Paz C, Neuman I, Cymeryng CB, Mendez CF, Finkielstein CV, Cornejo Maciel F, Podestá EJ. Involvement of arachidonic acid and the lipoxygenase pathway in mediating luteinizing hormone-induced testosterone synthesis in rat Leydig cells. Endocr Res 1997; 23:15-26. [PMID: 9187535 DOI: 10.1080/07435809709031839] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Evidence has been introduced linking the lipoxygenase products and steroidogenesis in Leydig cells, thereby supporting that this pathway may be a common event in the hormonal control of steroid synthesis. On the other hand, it has also been reported that lipoxygenase products of arachidonic acid (AA) may not be involved in Leydig cells steroidogenesis. In this paper, we investigated the effects of PLA2 and lipoxygenase pathway inhibitors on steroidogenesis in rat testis Leydig cells. The effects of two structurally unrelated PLA2 inhibitors (4-bromophenacyl bromide (BPB) and quinacrine) were determined. BPB blocked the LH- and Bt2cAMP-stimulated testosterone production but had no effect on 22(4)-OH-cholesterol conversion to testosterone. Quinacrine caused a dose-dependent inhibition of LH- and Bt2cAMP-induced steroidogenesis. The effects of different lipoxygenase pathway inhibitors (nordihydroguaiaretic acid (NDGA), 5,8,11,14-eicosatetraynoic acid (ETYA), caffeic acid and esculetin) have also been determined. Both NDGA and ETYA inhibited LH- and Bt2cAMP-stimulated steroid synthesis in a dose-related manner. Furthermore caffeic acid and esculetin also blocked the LH-stimulated testosterone production. Moreover, exogenous AA induced a dose-dependent increase of testosterone secretion which was inhibited by NDGA. Our results strongly support the previous concept that the lipoxygenase pathway is involved in the mechanism of action of LH on testis Leydig cells.
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Affiliation(s)
- P G Mele
- Department of Biochemistry, School of Medicine, University of Buenos Aires, Argentina
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7
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Przylipiak A, Rabe T, Kiesel L, Przylipiak J, Klinga K, Runnebaum B. Role of leukotriene C4 in follicle-stimulating hormone (FSH) secretion in female rat pituitary. Gynecol Endocrinol 1996; 10:95-100. [PMID: 8701793 DOI: 10.3109/09513599609097898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Leukotriene C4, at doses of 0.01 and 0.1 nmol/l added to superfused cells in pulse of 4-min duration, evoked follicle-stimulating hormone (FSH) release up to 12- to 26-fold of basal secretion. Higher and lower concentrations of leukotriene C4 were not able to induce FSH secretion. Gonadotropin-releasing hormone (GnRH)-induced FSH release was reduced by 38-57% by the leukotriene receptor antagonist FPL 55712 (10 mumol/l). Moreover, we have shown that FSH release occurs parallel to leukotriene C4 synthesis in rat anterior pituitary cells. Mellitin (100 nmol/l), an activator of phospholipase A2, induced FSH and radioactivity secretion in rat anterior pituitary cells previously preincubated for 24 h with [3H]arachidonic acid (AA).
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Affiliation(s)
- A Przylipiak
- Department of Obstetrics and Gynaecology, University Women's Hospital, Heidelberg, Germany
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8
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Mele PG, Dada LA, Paz C, Cymeryng CB, Cornejo Maciel MF, Neuman MI, Finkielstein CV, Mendez CF, Podestá EJ. Site of action of proteinases in the activation of steroidogenesis in rat adrenal gland. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1310:260-8. [PMID: 8599603 DOI: 10.1016/0167-4889(95)00177-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have investigated the effect of the proteinase inhibitors 1,10-phenantroline (OP) and phenylmethylsulfonyl fluoride (PMSF) on steroidogenesis in rat adrenal cortex. Both PMSF and OP inhibited adrenocorticotropin (ACTH)- and 8-Br cAMP-induced stimulation of corticosterone synthesis. On the contrary, arachidonic acid-induced stimulation of corticosterone synthesis was only slightly inhibited by PMSF and unchanged by OP. Intra- and extracellular cAMP levels were determined by radioimmunoassay. While PMSF did not affect neither the intra- nor the extracellular cAMP levels, OP decreased the intra- and extracellular levels of unstimulated as well as ACTH-stimulated cells. The site of action of the proteinase inhibitors was also studied by recombination of mitochondria with the different subcellular fractions in vitro. Addition of PMSF abolished the stimulation achieved by in vitro activation of cytosol by cAMP and PKA. On the other hand, OP completely inhibited the activation of mitochondria. Our results provide evidence for the involvement of proteinases in ACTH-induced stimulation of steroidogenesis in adrenal cortex both prior to the release of arachidonic acid and at the level of cholesterol transport from the outer to the inner mitochondrial membrane.
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Affiliation(s)
- P G Mele
- Department of Biochemistry, School of Medicine, University of Buenos Aires, Argentina
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9
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Ortmann O, Bakhit M, Bloh P, Schulz KD, Emons G. Ovarian steroids modulate gonadotropin-releasing hormone-induced biphasic luteinizing hormone secretory responses and inositol phosphate accumulation in rat anterior pituitary cells and alpha T3-1 gonadotrophs. J Steroid Biochem Mol Biol 1995; 54:101-9. [PMID: 7662583 DOI: 10.1016/0960-0760(95)00121-f] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The ovarian steroids estradiol and progesterone act as important modulators of GnRH-induced luteinizing hormone (LH) secretion from anterior pituitary cells. Recently, we demonstrated that the steroids are able to influence GnRH-stimulated Ca2+ mobilization from extra- and intracellular sources. Here we investigated the actions of estradiol and progesterone on GnRH-induced biphasic LH secretory responses in the model of perifused female rat pituitary cells. A 20 min GnRH stimulus elicited biphasic LH responses composed of an initial peak followed by a prolonged plateau phase. Both phases were equally enhanced by long-term (48 h) estradiol treatment. This action was facilitated by subsequent short-term progesterone treatment. In contrast, combined treatment with estradiol and progesterone for 48 h led to inhibited LH secretory profiles. To determine the steroid actions on the extracellular Ca2+ independent component of LH secretion we performed experiments using cells that were perifused with Ca2+ deficient medium. Under these conditions the cells responded exclusively with a single peak phase of LH secretion, which was augmented or inhibited by estradiol and progesterone treatment as described above. To test the hypothesis that an effect of estradiol and progesterone on GnRH-induced polyphophoinositide hydrolysis is responsible for their modulatory actions on Ca2+ signals and LH secretion we measured inositol phosphate (IP) accumulation after different steroid treatment paradigms in rat pituitary cells and alpha T3-1 immortalized gonadotrophs. GnRH-induced IP production was enhanced by long-term estradiol treatment. Short-term exposure of estradiol-primed cells to progesterone did not lead to significant changes of IP production. The long-term progesterone treatment paradigm enhanced GnRH-induced IP formation, while it decreased Ca2+ signals and LH secretion. Alpha T3-1 cells were used to perform more detailed analysis of IP formation. The actions of estradiol and progesterone on the production of inositol mono-, bis-, and trisphosphates were similar to those observed in the mixed cell population. It is concluded that estradiol and progesterone modulate both peak and plateau phases of GnRH-stimulated LH secretory responses, effects which are associated with their impact on Ca2+ signals. Our findings argue against a role of IP modulation in the mechanism of progesterone actions on Ca2+ signaling and LH secretion in gonadotrophs. Such a mechanism might be involved in the positive effects of estradiol in these cells.
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Affiliation(s)
- O Ortmann
- Department of Obstetrics and Gynecology, Philipps University, Marburg, Germany
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10
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Thomson FJ, Mitchell R. Differential involvement of phospholipase A2 in phorbol ester-induced luteinizing hormone and growth hormone release from rat anterior pituitary tissue. Mol Cell Endocrinol 1993; 95:75-83. [PMID: 8243810 DOI: 10.1016/0303-7207(93)90031-e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The protein kinase C (PKC) activator, phorbol 12,13-dibutyrate (PDBu) induced the release of both luteinizing hormone (LH) and growth hormone (GH) from proestrous rat anterior pituitary pieces in vitro. Phorbol 12,13-dibutyrate-induced LH, but not GH release was readily inhibited by the phospholipase A2 (PLA2) inhibitors, quinacrine, aristolochic acid, ONO-RS-082 and chloracysine. Furthermore, PDBu induced release of [3H]arachidonic acid ([3H]AA) from pre-labelled anterior pituitary tissue that was prevented in the presence of quinacrine, aristolochic acid and ONO-RS-082 but not the diglyceride lipase inhibitor RHC 80267. The effect of PDBu was completely inhibited by staurosporine and the selective PKC inhibitor Ro 31-8220 but only partially by low concentrations of H7; consistent with the involvement of both H7-sensitive and H7-resistant forms of PKC in the activation of PLA2 by PDBu. The protein synthesis inhibitor cycloheximide inhibited the release of both [3H]AA and LH that had been induced by PDBu, whereas LH release induced by the PLA2 activator mellitin was cycloheximide-insensitive. These results suggest that PKC activators may induce LH but not GH release from anterior pituitary tissue by a mechanism involving activation of a PLA2, brought about by a process which is reliant on protein synthesis.
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Affiliation(s)
- F J Thomson
- MRC Brain Metabolism Unit, University Department of Pharmacology, Edinburgh, UK
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11
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Eberhardt I, Kiesel L. Role of arachidonic acid and lipoxygenase products in the mechanism of gonadotropin secretion: an update. Prostaglandins Leukot Essent Fatty Acids 1992; 47:239-46. [PMID: 1492100 DOI: 10.1016/0952-3278(92)90192-l] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- I Eberhardt
- Department of Obstetrics and Gynecology, University of Heidelberg, Germany
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12
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Dan-Cohen H, Sofer Y, Schwartzman ML, Natarajan RD, Nadler JL, Naor Z. Gonadotropin releasing hormone activates the lipoxygenase pathway in cultured pituitary cells: role in gonadotropin secretion and evidence for a novel autocrine/paracrine loop. Biochemistry 1992; 31:5442-8. [PMID: 1610790 DOI: 10.1021/bi00139a004] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The formation and role of arachidonic acid (AA) and its metabolites during gonadotropin releasing hormone- (GnRH-) induced gonadotropin secretion were investigated in primary cultures of rat pituitary cells. Prelabeled cells ([3H]AA) responded to GnRH challenge with increased formation (about 2-fold) of the leukotrienes LTC4, LTD4, and LTE4 as well as 5- and 15-eicosatetraenoic acids (5- and 15-HETE) as identified by HPLC. Formation of leukotrienes and 15-HETE was further verified by specific radioimmunoassays. No significant increase in the formation of 12-HETE or of the cyclooxygenase products prostaglandin E (PGE) and thromboxane A2 by GnRH was noticed. Addition of physiological concentrations of LTC4 enhanced basal LH release, while subphysiological concentrations of LTC4 (10(-15)-10(-12) M) inhibited GnRH-induced LH release by about 35% (p less than 0.02). Using specific lipoxygenase inhibitors L-656,224 and MK 886, we found inhibition of GnRH-induced LH release by about 40% at concentrations known to specifically inhibit the 5-lipoxygenase pathway. The peptidoleukotriene receptor antagonist ICI 198,615 inhibited LTC4- and LTE4-induced LH release and surprisingly also the effect of GnRH on LH release by 40%. The data strongly suggest a role for AA and its lipoxygenase metabolites in the on/off reactions of GnRH upon LH release. The data also present a novel amplification cycle in which newly formed leukotrienes become first messengers and establish an autocrine/paracrine loop.
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Affiliation(s)
- H Dan-Cohen
- Department of Biochemistry, Tel Aviv University, Israel
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13
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Gerozissis K, Bommelaer-Bayet MC, Wisner A, Saadi M, Ramassamy C, Dray F. Prostaglandin E2 and leukotriene C4-induced luteinizing hormone-releasing hormone release from immature and adult male rat median eminences in vitro: eicosanoid formation and binding parameters. PROSTAGLANDINS 1991; 41:345-57. [PMID: 1871376 DOI: 10.1016/0090-6980(91)90004-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The amounts of prostaglandin E2 formed in vitro by the median eminences of adult male rats were greater than those produced by the median eminences of immature, 22 day-old rats. However, the amount of leukotriene C4 produced by the adult rat median eminences was lower than that produced by the immature rat median eminences. Analysis of the prostaglandin E2 binding parameters of hypothalamic P2 membrane fractions indicates that there are two binding components, one high affinity (RH) and one low affinity (RL) in both adult and immature rats. The maximal binding capacity of RH from adult rat membranes was significantly lower than that of immature rat membranes, correlating with greater prostaglandin E2 production by the adult rat median eminence. Only one leukotriene C4 binding site was detected in both adult and immature rat membranes. Exogenous prostaglandin E2 and leukotriene C4 both stimulated, the release of luteinizing hormone-releasing hormone to the same extent from both the adult and immature median eminences.
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Affiliation(s)
- K Gerozissis
- INSERM U.207, Institut Pasteur, URIA, Paris, France
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14
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Eberhardt I, Kiesel L, Rosenberg K, Klinga K, Runnebaum B. Characterization of leukotriene C4 binding in anterior pituitary membrane preparations. PROSTAGLANDINS 1991; 41:185-99. [PMID: 1850146 DOI: 10.1016/0090-6980(91)90030-j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Pituitary cells produce leukotrienes (LTs) and respond to exogenous administration of LTs by releasing gonadotropins. Specific high affinity leukotriene C4 (LTC4) binding has been found in membrane preparations of bovine anterior pituitaries. Unlabelled LTC4 displaced specific [3H]LTC4 binding. Other leukotrienes (LTB4, LTD4, LTE4, LTF4) did not compete with [3H]LTC4 for binding sites when administered at increasing concentrations together with a constant amount of radioligand indicating that the binding is highly specific for LTC4. Scatchard analysis of binding data obtained from saturation studies revealed a single binding site for [3H]LTC4 with a Kd of 8.95 +/- 5.53 nM and a B max of 15.44 +/- 6.93 pmol per mg of membrane protein. Glutathione S-transferase, a possible LTC4 binding site, did not display activity in the membrane fraction although the two glutathione derivates S-octylglutathione and S-decylglutathione competed with LTC4 in binding experiments. As leukotrienes are potent stimulators of gonadotropin secretion and modulators of gonadotropin-releasing hormone (GnRH)-induced gonadotropin release it is concluded that leukotrienes may be involved in the signal transduction pathway of GnRH and that they may act via a specific and high affinity receptor.
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Affiliation(s)
- I Eberhardt
- Department of Gynecology and Obstetrics, University of Heidelberg, Federal Republic of Germany
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15
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Carlson RO, Levitan IB. Constant turnover of arachidonic acid and inhibition of a potassium current in Aplysia giant neurons. J Membr Biol 1990; 116:261-72. [PMID: 2388257 DOI: 10.1007/bf01868465] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Steady-state currents at hyperpolarized membrane potentials were studied in the homologous giant neurons, LP1 and R2, of Aplysia using two-electrode voltage clamp. Nearly half of the steady-state current at voltages more hyperpolarized than -70 mV had characteristics similar to the inwardly rectifying potassium current (IR) described previously in Aplysia neurons. The pharmacological agents 4-bromophenacylbromide, indomethacin, and the phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate were found to modulate IR. IR was stimulated with BPB and indomethacin and inhibited with TPA. These agents altered IR by a mechanism independent of cAMP, which can also modulate IR. The effects of these modulators are consistent with their actions on arachidonic acid (AA) metabolism in Aplysia nervous system, suggesting AA may constitutively inhibit IR. When ganglia were perfused for 12 hr with medium containing BSA to absorb extracellular fatty acids, IR was increased nearly twofold. This increase was partially inhibited by addition of AA to the perfusion medium, and completely inhibited by pretreatment of ganglia with BPB. Although no direct effect of short-term exposure to exogenous AA was observed, long term exposure to exogenous AA and several other unsaturated fatty acids was accompanied by a decrease in IR.
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Affiliation(s)
- R O Carlson
- Graduate Department of Biochemistry, Brandeis University, Waltham, Massachusetts 02254
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16
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Przylipiak A, Kiesel L, Przylipiak M, Runnebaum B. Differences in luteinizing hormone release stimulated in rat anterior pituitary cells by leukotriene C4 and by gonadotropin-releasing hormone in vitro. EXPERIENTIA 1990; 46:298-300. [PMID: 2178956 DOI: 10.1007/bf01951771] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Continuous administration of leukotriene C4 (LTC4, 10(-10) M) to superfused rat anterior pituitary cells increased LH release for 40 min only, whereas in a parallel experiment gonadotropin-releasing hormone (GnRH, 10(-9) M) evoked a continuous increase in hormone secretion. In contrast to GnRH, LTC4 did not desensitize rat anterior pituitary cells. The secretory action resulting from the administration of LTC4 (10(-10) M) was abolished for 40 min after previous stimulation. The results documented the dual action of LTC4 on LH exocytosis.
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Affiliation(s)
- A Przylipiak
- Department of Obstetrics and Gynecology, Division of Gynecological Endocrinology, Heidelberg, Federal Republic of Germany
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17
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Przylipiak A, Kiesel L, Habenicht AJ, Przylipiak M, Runnebaum B. Exogenous action of 5-lipoxygenase by its metabolites on luteinizing hormone release in rat pituitary cells. Mol Cell Endocrinol 1990; 69:33-9. [PMID: 2157615 DOI: 10.1016/0303-7207(90)90086-n] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The stimulatory effect of exogenously administered potato 5-lipoxygenase (0.1-0.3 U/2 ml) on luteinizing hormone (LH) release was demonstrated in rat anterior pituitary cells in a superfusion system. Nordihydroguaiaretic acid (NDGA), an inhibitor of 5-lipoxygenase, abolished the effect of the enzyme on LH secretion. The secretory effect on LH after 5-lipoxygenase administration was biphasic and dependent on Ca2+ indicating that 5-lipoxygenase affects LH release through its oxygenation reaction. Another series of experiments demonstrated that activation of 5-lipoxygenase, expressed as production of leukotriene (LT) B4 and C4 (728 +/- 127 pg/10(6) cells and 178 +/- 23 pg/10(6) cells, respectively) occurs in rat pituitary cells after addition of Ca2+ ionophore A23187. However, LTB4 and LTC4 were not formed by pituitary cells that had previously been desensitized by gonadotropin-releasing hormone (GnRH), the physiological ligand of LH release. These results are consistent with a role of 5-lipoxygenase metabolites in the mechanism of GnRH-induced LH secretion.
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Affiliation(s)
- A Przylipiak
- Department of Gynecology and Obstetrics, University of Heidelberg, F.R.G
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18
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Saadi M, Gerozissis K, Rougeot C, Minary P, Dray F. Leukotriene C4-induced release of LHRH into the hypophyseal portal blood and of LH into the peripheral blood. Life Sci 1990; 46:1857-65. [PMID: 2194089 DOI: 10.1016/0024-3205(90)90238-m] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Intracerebroventricular (i.c.v.) administration of leukotriene (LT) C4 at doses of 2, 0.5 and 0.2 micrograms/rat significantly stimulated (3-12 fold) the release of LH into the peripheral blood of male rats. Injection of anti-LHRH serum had no effect on LTC4-stimulated LH release, but did block PGE2- stimulated LH release. I.c.v.- infused LTC4 also stimulated the release of LHRH into the hypophyseal portal blood. This is the first report of an in vivo action of LTC4 on the release of a hypothalamic releasing factor (LHRH) and a pituitary hormone (LH). These observations, plus in vitro results, clearly show that LTC4 stimulates LH release by acting on both the hypothalamus, causing LHRH release, and on the pituitary. Then the action of LTC4 on LH release in vivo is quite different from the indirect action of PGE2.
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Affiliation(s)
- M Saadi
- Institut Pasteur, URIA, INSERM U 207, Paris, France
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19
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Affiliation(s)
- A M Cowell
- Department of Pharmacology, Charing Cross and Westminster Medical School, London, U.K
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20
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Pace-Asciak CR, Asotra S. Biosynthesis, catabolism, and biological properties of HPETEs, hydroperoxide derivatives of arachidonic acid. Free Radic Biol Med 1989; 7:409-33. [PMID: 2514125 DOI: 10.1016/0891-5849(89)90125-1] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The oxygenation of arachidonic acid by lipoxygenases results in the formation of HPETEs (hydroperoxyeicosatetraenoic acids), the first products of the LOX pathway. These compounds are short lived and are catabolised into various families of more stable compounds of which the HETEs, hepoxilins, lipoxins and leukotrienes have been identified so far. The development of new techniques have helped to identify and understand the structures of various HPETEs and only recently the biological effects of HPETEs and their various catabolites are being unraveled. Although lipoxygenases are ubiquitous, not all tissues possess the same spectrum of lipoxygenase enzymes. Hence different HPETEs can be formed in different tissues. Recent studies have revealed that HPETEs or products derived from them possess a diversity of important biological properties including the regulation of electrolyte flux and eicosanoid and corticosterone syntheses, release of histamine, regulation of oocyte maturation and release of various reproductive hormones. HPETEs appear to be involved in some pathological conditions viz, skin psoriasis, Clarkson's disease, nerve injury and spinal cord ischemia. These novel eicosanoids are associated with the release of insulin as well as renin. Recently HPETEs have been suggested to act as second messengers in the Aplysia sensory neurons and its catabolite, hepoxilin, has been demonstrated to have effects on mammalian hippocampal neurons. The purpose of this review is to provide a brief summary of the formation of the HPETEs and the various families of compounds derived from them as well as the various types of biological activities for these products described so far.
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Affiliation(s)
- C R Pace-Asciak
- Research Institute, Hospital for Sick Children, Toronto, Canada
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21
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Chang JP, Morgan RO, Catt KJ. Dependence of secretory responses to gonadotropin-releasing hormone on diacylglycerol metabolism. Studies with a diacylglycerol lipase inhibitor, RHC 80267. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)37329-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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22
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Miyake A, Nishizaki T, Ikegami H, Koike K, Hirota K, Tanizawa O. Possible involvement of lipoxygenase pathway of arachidonic acid in rat pituitary hormone release in vitro. J Endocrinol Invest 1988; 11:805-8. [PMID: 2852195 DOI: 10.1007/bf03350230] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The roles of arachidonic acid (AA) and its lipoxygenase products in control of secretion of anterior pituitary hormones were studied in vitro using cultured cells. AA (10(-4)M) and 5-hydroxy-eicosatetraenoic acid (5HETE) (5 x 10(-6)M) significantly (p less than 0.05) stimulated the releases of LH, TSH, GH, PRL, ACTH and beta-endorphin (beta-E). Added leukotriene B4 (LTB4) (5 x 10(-6)M) also caused significant increases in the secretions of LH, GH, ACTH and beta-E. The other lipoxygenase metabolites tested, 12HETE, 15HETE, LTA4, LTC4 and LTD4, had no effect on the releases of anterior pituitary hormones. These results suggest that AA and 5-lipoxygenase metabolites may be involved in the control of the releases of anterior pituitary hormones.
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Affiliation(s)
- A Miyake
- Department of Obstetrics and Gynecology, Osaka University Medical School, Japan
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23
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Przylipiak A, Kiesel L, Rabe T, Helm K, Przylipiak M, Runnebaum B. Epidermal growth factor stimulates luteinizing hormone and arachidonic acid release in rat pituitary cells. Mol Cell Endocrinol 1988; 57:157-62. [PMID: 3260875 DOI: 10.1016/0303-7207(88)90045-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Epidermal growth factor (EGF) directly enhanced luteinizing hormone (LH) release from dispersed rat pituitary cells in monolayer cultures as well as in superfusion columns. This 2.3-fold stimulatory effect was dose and time dependent and was also reconfirmed in a superfusion system. Retinal, a protein kinase C inhibitor, counteracted the EGF effect only partially. Further experiments were therefore carried out to investigate alternate EGF mechanisms. Nordihydroguaiaretic acid and chloroquine suppressed the stimulatory effect of EGF in a dose-dependent manner. Moreover, EGF (10(-7) M) stimulated [3H]arachidonate release from pre-labelled rat pituitary cells. This indicates that phospholipase A2 and arachidonic acid may be involved in EGF action on LH release from rat pituicytes.
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Affiliation(s)
- A Przylipiak
- Department of Obstetrics and Gynaecology, University of Heidelberg, F.R.G
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24
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Chapter 8 The mechanisms of action of luteinizing hormone. II. Transducing systems and biological effects. ACTA ACUST UNITED AC 1988. [DOI: 10.1016/s0167-7306(08)60663-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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25
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Affiliation(s)
- A A Spector
- Department of Biochemistry, University of Iowa, Iowa City 52242
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26
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Kiesel L, Helm K, Bertges K, Maier C, Rabe T, Runnebaum B. Contraceptive progestins and gonadotropin secretion in vitro. JOURNAL OF STEROID BIOCHEMISTRY 1987; 27:995-1002. [PMID: 3121934 DOI: 10.1016/0022-4731(87)90180-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In an in vitro bioassay using rat pituitary cell cultures the effect of contraceptive progestins was tested on basal and gonadotropin-releasing hormone (GnRH)-induced luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion in vitro. Progestins diminished gonadotropin release in pituitary cells stimulated with GnRH, but did not alter basal values. This inhibitory effect was dose dependent in a range of 10(-10)-10(-5) M tested and the inhibitory action of most of the progestins examined was more potent than that of progesterone. The maximal reduction of LH and FSH values was by 60% of GnRH-induced control levels. Progestins also caused a shift in sensitivity of cells to GnRh (10(-12)-10(-6) M). When time dependence was investigated, some progestins potentiated GnRH effect on gonadotropins in pituitary cell cultures pre-incubated for a short time (4 h) with steroids. More prolonged pre-incubations from 23 to 71 h resulted in a progressive suppression of LH and FSH response to GnRH (10(-7) M). In order to examine intracellular effects, cells were pretreated with progestins and inositol phosphate metabolism was investigated. The data obtained in pituitary cells give evidence that polyphosphoinositide breakdown is potentially an early step in the action of GnRH on gonadotropin secretion by providing diacylglycerol and inositol phosphates. Addition of gonadotropin-releasing hormone to myo-2[3H]inositol-prelabeled rat pituitary cells in primary culture evoked a dose-dependent increase of the accumulation of [3H]inositol phosphates with a rise of inositol triphosphate, inositol diphosphate and inositol monophosphate within 1 min. Using one contraceptive progestin, gestoden, inositol phosphate production was inhibited by 80% compared to controls of GnRH-treated cells without the addition of steroids. The data obtained in this study suggest that this in vitro bioassay using rat pituitary cells is a useful tool in testing progestational compounds regarding their potency on gonadotropin release. In addition, these results show that one possible site of interference of progestins with GnRH-induced gonadotropin secretion may involve polyphosphoinositide breakdown.
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Affiliation(s)
- L Kiesel
- Department of Obstetrics and Gynecology, University of Heidelberg, Federal Republic of Germany
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