[A Case of Primary Somatostatin-Producing Tumor of the Duodenum with Liver Metastases with Long-Term Survival of More than 20 Years]

A 52-year-old woman underwent esophagogastroduodenoscopy after an abnormal medical examination, which revealed a mass lesion over half the circumference of the superior duodenal angulus. Immunostaining was diffusely positive for somatostatin, synaptophysin, and chromogranin A. A 3 cm-sized mass in the pancreaticoduodenal region and multiple nodular lesions of a few mm in both lobes of the liver were revealed by CT. The diagnosis is primary somatostatin-producing tumor of the duodenum with multiple liver metastases. She underwent gastric jejunal bypass for impaired transit. Afterwards hepatic infusion and systemic chemotherapy were continued, and 5 years passed without progression. When she stopped chemotherapy for 6 months, she started somatostatin analogue therapy because of the increase of the tumors. The tumors did not increase, and 20 years have passed since the start of treatment. We report a case of primary somatostatin-producing tumor of the duodenum with liver metastases that is still alive for a long period of time, with a review of the literature.

External Validity of Somatostatin Analogs Trials in Advanced Neuroendocrine Neoplasms: The GETNE-TRASGU Study

INTRODUCTION

Somatostatin analogs (SSA) prolong progression-free survival (PFS) in patients with well-differentiated gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). However, the eligibility criteria in randomized clinical trials (RCTs) have been restricted, which contrasts with the vast heterogeneity found in NENs.

METHODS

We identified patients with well-differentiated (Ki-67% ≤20%), metastatic GEP-NENs treated in first line with SSA monotherapy from the Spanish R-GETNE registry. The therapeutic effect was evaluated using a Bayesian Cox model. The objective was to compare survival-based outcomes from real-world clinical practice versus RCTs.

RESULTS

The dataset contained 535 patients with a median age of 62 years (range: 26-89). The median Ki-67% was 4 (range: 0-20). The most common primary tumor sites were as follows: midgut, 46%; pancreas, 34%; unknown primary, 10%; and colorectal, 10%. Half of the patients received octreotide LAR (n = 266) and half, lanreotide autogel (n = 269). The median PFS was 28.0 months (95% CI: 22.1-32.0) for octreotide versus 30.1 months (95% CI: 23.1-38.0) for lanreotide. The overall hazard ratio for lanreotide versus octreotide was 0.90 (95% credible interval: 0.71-1.12). The probability of effect sizes >30% with lanreotide versus octreotide was 2 and 6% for midgut and foregut NENs, respectively.

CONCLUSION

Our study evaluated the external validity of RCTs examining SSAs in the real world, as well as the main effect-modifying factors (progression status, symptoms, tumor site, specific metastases, and analytical data). Our results indicate that both octreotide LAR and lanreotide autogel had a similar effect on PFS. Consequently, both represent valid alternatives in patients with well-differentiated, metastatic GEP-NENs.

Differential Excitability of PV and SST Neurons Results in Distinct Functional Roles in Inhibition Stabilization of Up States

Up states are the best studied example of an emergent neural dynamic regime. Computational models based on a single class of inhibitory neurons indicate that Up states reflect bistable dynamic systems in which positive feedback is stabilized by strong inhibition and predict a paradoxical effect in which increased drive to inhibitory neurons results in decreased inhibitory activity. To date, however, computational models have not incorporated empirically defined properties of parvalbumin (PV) and somatostatin (SST) neurons. Here we first experimentally characterized the frequency-current (F-I) curves of pyramidal (Pyr), PV, and SST neurons from mice of either sex, and confirmed a sharp difference between the threshold and slopes of PV and SST neurons. The empirically defined F-I curves were incorporated into a three-population computational model that simulated the empirically derived firing rates of pyramidal, PV, and SST neurons. Simulations revealed that the intrinsic properties were sufficient to predict that PV neurons are primarily responsible for generating the nontrivial fixed points representing Up states. Simulations and analytical methods demonstrated that while the paradoxical effect is not obligatory in a model with two classes of inhibitory neurons, it is present in most regimes. Finally, experimental tests validated predictions of the model that the Pyr ↔ PV inhibitory loop is stronger than the Pyr ↔ SST loop.SIGNIFICANCE STATEMENT Many cortical computations, such as working memory, rely on the local recurrent excitatory connections that define cortical circuit motifs. Up states are among the best studied examples of neural dynamic regimes that rely on recurrent excitatory excitation. However, this positive feedback must be held in check by inhibition. To address the relative contribution of PV and SST neurons, we characterized the intrinsic input-output differences between these classes of inhibitory neurons and, using experimental and theoretical methods, show that the higher threshold and gain of PV leads to a dominant role in network stabilization.

Efficacy of a Novel Second-Generation Somatostatin-Dopamine Chimera (TBR-065) in Human Medullary Thyroid Cancer: A Preclinical Study

INTRODUCTION

Somatostatin and dopamine (DA) receptors have a pivotal role in controlling hormone secretion and cell proliferation in different neuroendocrine neoplasms, including medullary thyroid cancer (MTC). In the present preclinical study, we evaluated the anti-tumor activity of TBR-065 (formerly BIM-23B065), a second-generation somatostatin-DA chimera, in 2 human MTC cell lines.

METHODS

The effects of lanreotide (LAN) and TBR-065 on cell growth and proliferation, calcitonin (CT) secretion, cell cycle, apoptosis, cell migration, and tumor-induced angiogenesis have been evaluated through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, DNA flow cytometry with propidium iodide (PI), Annexin V-FITC/PI staining, electrochemiluminescence immuno assay, wound-healing assay, and zebrafish platform, respectively.

RESULTS

TBR-065 exerted a more prominent anti-tumor activity than LAN in both MTC cell lines, as shown by inhibition of cell proliferation (maximal inhibition in TT: -50.3 and -37.6%, respectively; in MZ-CRC-1: -58.8 and -27%, respectively) and migration (in TT: -42.7 and -22.9%, respectively; in MZ-CRC-1: -75.5 and -58.2%, respectively). Only the new chimera decreased significantly the fraction of cells in S phase (TT: -33.8%; MZ-CRC-1: -18.8%) and increased cells in G2/M phase (TT: +13%; MZ-CRC-1: +30.5%). In addition, TBR-065 exerted a more prominent pro-apoptotic effect than LAN in TT cells. A concomitant decrease in CT secretion was observed after 2 days of incubation with both drugs, with a more relevant effect of TBR-065. However, neither LAN nor TBR-065 showed any effect on tumor-induced angiogenesis, as evaluated using a zebrafish/tumor xenograft model.

DISCUSSION/CONCLUSION

In MTC cell lines, a second-generation somatostatin-DA analog, TBR-065, exerts a more relevant anti-tumor activity than LAN, through modulation of cell cycle, induction of apoptosis, and reduction in migration. Further studies are required to establish whether TBR-065 has comparable potent inhibitory effects on tumor growth in vivo.

Antiproliferative Effect of Above-Label Doses of Somatostatin Analogs for the Management of Gastroenteropancreatic Neuroendocrine Tumors

BACKGROUND

Above-label doses of somatostatin analogs (SSAs) are increasingly utilized in the management of inoperable/metastatic gastroenteropancreatic neuroendocrine tumors (GEP-NETs), progressing on standard 4-weekly regimens.

OBJECTIVE

To evaluate the antiproliferative effect of 3-weekly SSA administration in a retrospective GEP-NET cohort.

METHODS

Patients with advanced GEP-NET, treated with long-acting release (LAR) octreotide 30 mg or lanreotide Autogel 120 mg at a 3-weekly interval, after disease progression on standard 4-weekly doses, were retrospectively identified. Clinicopathologic and treatment response data were collected. Progression-free survival (PFS; dose escalation to radiographic progression or death) was estimated with the Kaplan-Meier method. Factors associated with PFS were identified with the Cox proportional-hazards model.

RESULTS

The inclusion criteria were fulfilled by 105 patients. Octreotide LAR was administered to 60 (57%) and lanreotide Autogel to 45 (43%). Indications for dose escalation were breakthrough carcinoid symptoms (58%), radiographic progression (35%) and/or increasing biomarkers (11%). Diarrheal and/or flushing symptomatic improvement was identified in 37/67 cases (55%) and 30/55 cases (55%) with available data, respectively. The disease control rate (radiographic partial response or stable disease) was achieved in 53 patients (50%). Median PFS was 25.0 months (95% CI 16.9-33.1). Patients with radiographic progression <12 months from 4-weekly SSA initiation had worse PFS after dose escalation (7.0 vs. 17.0 months, p = 0.002). In multivariate analysis, pancreatic NETs, a Ki-67 index ≥5% and multiple extrahepatic metastases were independently associated with inferior PFS.

CONCLUSIONS

Above-label doses of SSAs may offer a considerable prolongation of PFS and could be utilized as a bridge to other more toxic treatments. Patients with small bowel/colorectal primaries, a Ki-67 index <5% and absence of/limited extrahepatic metastases are more likely to benefit from this approach.

Multidisciplinary management of acromegaly: A consensus

The 13th Acromegaly Consensus Conference was held in November 2019 in Fort Lauderdale, Florida, and comprised acromegaly experts including endocrinologists and neurosurgeons who considered optimal approaches for multidisciplinary acromegaly management. Focused discussions reviewed techniques, results, and side effects of surgery, radiotherapy, and medical therapy, and how advances in technology and novel techniques have changed the way these modalities are used alone or in combination. Effects of treatment on patient outcomes were considered, along with strategies for optimizing and personalizing therapeutic approaches. Expert consensus recommendations emphasize how best to implement available treatment options as part of a multidisciplinary approach at Pituitary Tumor Centers of Excellence.

A New Generation Somatostatin-Dopamine Analogue Exerts Potent Antitumoral Actions on Pituitary Neuroendocrine Tumor Cells

BACKGROUND

Pituitary neuroendocrine tumors (PitNETs) represent approximately 15% of all intracranial tumors and usually are associated with severe comorbidities. Unfortunately, a relevant number of patients do not respond to currently available pharmacological treatments, that is, somatostatin analogs (SSAs) or dopamine-agonists (DA). Thus, novel, chimeric somatostatin/dopamine compounds (dopastatins) that could improve medical treatment of PitNETs have been designed.

OBJECTIVE

This study aims to determine the direct therapeutic effects of a new-generation dopastatin, BIM-065, on primary cell cultures from different PitNETs subtypes.

METHODS

Thirty-one PitNET-derived cell cultures (9 corticotropinomas, 9 somatotropinomas, 11 nonfunctioning pituitary adenomas [NFPAs], and 2 prolactinomas), were treated with BIM-065, and key functional endpoints were assessed (cell viability, apoptosis, hormone secretion, expression levels of key genes, free cytosolic [Ca2+]i dynamics, etc.). AtT-20 cell line was used to evaluate signaling pathways in response to BIM-065.

RESULTS

This chimeric compound decreased cell viability in all corticotropinomas and somatotropinomas tested, but not in NFPAs. BIM-065 reduced ACTH, GH, chromogranin-A and PRL secretion, and increased apoptosis in corticotropinomas, somatotropinomas, and NFPAs. These effects were possibly mediated through modulation of pivotal signaling cascades like [Ca2+]i kinetic and Akt- or ERK1/2-phosphorylation.

CONCLUSIONS

Our results unveil a robust antitumoral effect in vitro of the novel chimeric compound BIM-065 on the main PitNET subtypes, inform on the mechanisms involved, and suggest that BIM-065 could be an efficacious therapeutic option to be considered in the treatment of PitNETs.

Peritoneal Carcinomatosis in Gastro-Entero-Pancreatic Neuroendocrine Neoplasms: Clinical Impact and Effectiveness of the Available Therapeutic Options

BACKGROUND

Peritoneal carcinomatosis (PC) can affect the quality of life of patients with gastro-entero-pancreatic neuroendocrine neoplasms (GEP-NENs). Peritoneal disease control by medical therapies in these patients has been poorly investigated Objectives: To describe, in a consecutive series of GEP-NENs, the clinical impact of PC and to report the effectiveness of available treatments in PC control.

METHODS

A retrospective, monocenter analysis was performed of 135 GEP-NENs (1993-2016) with at least a 12-month follow-up. Peritoneal disease progression was defined as detection of a significant increase in size or appearance of new implants by imaging.

RESULTS

A total of 62.9% of cases had diffuse PC (involving at least 2 abdominal quadrants). According to WHO 2017 classification, cases were 42.3% neuroendocrine tumors NET-G1, 45.5% NET-G2, 6.5% NET-G3, 4.9% neuroendocrine carcinomas NEC-G3, and 0.8% mixed neuroendocrine-nonneuroendocrine neoplasms. Bowel obstruction occurred in 30 (22.2%) patients mainly depending on size of peritoneal implants (HR: 1.10; 95% CI: 1.02-1.20; p = 0.01). Patients with diffuse PC treated with peptide receptor radionuclide therapy (PRRT) showed peritoneal progression in 37.5% of cases, and bowel obstruction or ascites in 28.1%. Better peritoneal disease control was observed in cases receiving somatostatin analogs at first-line therapy, probably due to a less aggressive disease behavior for these patients.

CONCLUSIONS

Bowel obstruction is not uncommon in GEP-NENs with PC. PRRT should be adopted with caution in GEP-NENs with diffuse PC, but larger series are needed to confirm these data.

Intraoperative Gamma Probe Detection of Head and Neck Paragangliomas with 111In-Pentetreotide: A Pilot Study

Aims and background

The aim of this study was to assess whether intraoperative radiolocalization of head and neck paragangliomas with 111In-pentetreotide may increase surgical effectiveness, reducing the risk of recurrence.

Methods

Our study included eight patients with untreated, recently diagnosed paragangliomas (four unilateral and four bilateral tumors of the carotid body). After iv injection of −150 MBq 111In-pentetreotide, preoperative somatostatin receptor scintigraphy (SRS) was performed. SPECT of the neck was performed at four hours and planar Images of the head and neck were also obtained at four and 24 hours post injection. Scintigraphy was always compared with the results of conventional imaging methods (MRI, angiography and sonography). Intraoperative detection was performed on 11 lesions 24 hours after radiopharmaceutical administration using a handheld gamma probe.

Results

Preoperative SRS showed high radiotracer uptake in all patients. All the intraoperatively detected lesions were radically resected and histologically confirmed to be involved by tumor. No false positive results were recorded. Gamma probe detection revealed a small intracranial extension not detected by other imaging methods in a patient with a paraganglioma of the right carotid, and partial involvement of the carotid artery in another patient. During follow-up (median 3.5 years; range, 4 months-7 years) all patients remained disease free according to all parameters.

Conclusions

To our knowledge, this is the first experience of radioguided surgery in paraganglioma. Although our study included a relatively small number of patients, we suggest that intraoperative gamma probe detection may be a powerful tool to improve surgical effectiveness.

Elfn1-Induced Constitutive Activation of mGluR7 Determines Frequency-Dependent Recruitment of Somatostatin Interneurons

Excitatory synapses onto somatostatin (SOM) interneurons show robust short-term facilitation. This hallmark feature of SOM interneurons arises from a low initial release probability that regulates the recruitment of interneurons in response to trains of action potentials. Previous work has shown that Elfn1 (extracellular leucine rich repeat and fibronectin Type III domain containing 1) is necessary to generate facilitating synapses onto SOM neurons by recruitment of two separate presynaptic components: mGluR7 (metabotropic glutamate receptor 7) and GluK2-KARs (kainate receptors containing glutamate receptor, ionotropic, kainate 2). Here, we identify how a transsynaptic interaction between Elfn1 and mGluR7 constitutively reduces initial release probability onto mouse cortical SOM neurons. Elfn1 produces glutamate-independent activation of mGluR7 via presynaptic clustering, resulting in a divergence from the canonical "autoreceptor" role of Type III mGluRs, and substantially altering synaptic pharmacology. This structurally induced determination of initial release probability is present at both layer 2/3 and layer 5 synapses. In layer 2/3 SOM neurons, synaptic facilitation in response to spike trains is also dependent on presynaptic GluK2-KARs. In contrast, layer 5 SOM neurons do not exhibit presynaptic GluK2-KAR activity at baseline and show reduced facilitation. GluK2-KAR engagement at synapses onto layer 5 SOM neurons can be induced by calmodulin activation, suggesting that synaptic function can be dynamically regulated. Thus, synaptic facilitation onto SOM interneurons is mediated both by constitutive mGluR7 recruitment by Elfn1 and regulated GluK2-KAR recruitment, which determines the extent of interneuron recruitment in different cortical layers.SIGNIFICANCE STATEMENT This study identifies a novel mechanism for generating constitutive GPCR activity through a transsynaptic Elfn1/mGluR7 structural interaction. The resulting tonic suppression of synaptic release probability deviates from canonical autoreceptor function. Constitutive suppression delays the activation of somatostatin interneurons in circuits, necessitating high-frequency activity for somatostatin interneuron recruitment. Furthermore, variations in the synaptic proteome generate layer-specific differences in facilitation at pyr → SOM synapses. The presence of GluK2 kainate receptors in L2/3 enhances synaptic transmission during prolonged activity. Thus, layer-specific synaptic properties onto somatostatin interneurons are mediated by both constitutive mGluR7 recruitment and regulated GluK2 kainate receptor recruitment, revealing a mechanism that generates diversity in physiological responses of interneurons.

Updating the picture of layer 2/3 VIP-expressing interneuron function in the mouse cerebral cortex

For years, interneurons expressing vasoactive intestinal peptide (VIP) interneurons and their function within the neocortex have been shrouded in mystery. Their relatively small size and minimal representation in the cortex have made investigation difficult. Due to their service role performed in co‑operation with glia and blood vessels to supply energy during neuronal activation in the brain, the contribution of VIP interneurons to local neuronal circuit function was not appreciated. VIP interneurons in the neocortex account for roughly 12% of all interneurons. They have been described as a subgroup of the third largest population of 5-hydroxytryptamine 3a (5HT3a) receptor‑expressing interneurons, non‑overlapping with interneuron populations expressing parvalbumin (PV) or somatostatin (SST). However, it was recently shown that only half of VIP interneurons display a 5HT3a receptor response and a subset of VIP interneurons in visual cortex co‑express SST. Over the last several years, due to new technical advancements, many facts have emerged relating to VIP interneuron phylogenetic origin, operational mechanisms within local circuits and functional significance. Some of these discoveries have dramatically shifted the perception of VIP interneurons. This review focuses on the function of the VIP interneurons residing in layer 2/3 of the mouse neocortex.

Three-Dimensional Analysis of the Human Pancreas

Pancreatic islets are endocrine micro-organs scattered throughout the exocrine pancreas. Islets are surrounded by a network of vasculature, ducts, neurons, and extracellular matrix. Three-dimensional imaging is critical for such structural analyses. We have adapted transparent tissue tomography to develop a method to image thick pancreatic tissue slices (1 mm) with multifluorescent channels. This method takes only 2 to 3 days from specimen preparation and immunohistochemical staining to clearing tissues and imaging. Reconstruction of the intact pancreas visualizes islets with β, α, and δ cells together with their surrounding networks. Capturing several hundred islets at once ensures sufficient power for statistical analyses. Further surface rendering provides clear views of the anatomical relationship between islets and their microenvironment as well as the basis for volumetric quantification. As a proof-of-principle demonstration, we show an islet size-dependent increase of intraislet capillary density and an inverse decrease in sphericity.

Development of Fetal Sheep Pancreas after Transplantation into Athymic Mice

The capacity of the fetal sheep pancreas to grow and function when transplanted into athymic mice was examined to determine whether this source of tissue might be of potential use in reversing diabetes. For this purpose fetal sheep pancreases were obtained in the period between 50 days of gestation and fullterm (148 days). Explants (1 mm3) in organ culture secreted insulin for at least 7 days, but in steadily diminishing amounts. Acute exposure to arginine (10 mM) and theophylline (10 mM), but not glucose (20 mM), calcium chloride (10 mM), and sodium butyrate (10 mM), caused acute secretion of insulin. Explants survived for many months when grafted beneath the renal capsule of athymic mice, but their growth was less, the epithelial-like component smaller, and the percentage of endocrine cells (31 ± 5%) fewer than the case of transplanted fetal human pancreas. The β cell was the predominant endocrine cell in the ungrafted fetal sheep pancreas. In the transplanted fetal sheep pancreas this was not so, the α and PP cells being dominant—β:α:S:PP = 3:14:3:11. This pattern was unchanged when the recipient mice were hyperglycemic—β:α:δ:PP = 4:13:4:28, with no reduction of blood glucose levels being observed for up to 4 mo after transplantation. Altering the site of transplantation to the spleen or liver did not improve survival of the endocrine cells. Fetal sheep pancreatic explants when transplanted into athymic rats failed to survive. Thus, although the unusual pattern of endocrine differentiation in fetal sheep pancreas transplanted into athymic mice makes it an interesting model for further studies of fetal development, it is not of benefit in normalizing the blood glucose levels of the recipients.

Serotonin storage and chromogranins: an experimental study in rat gastric endocrine cells

Chromogranins (Cg) and secretogranins (Sg) are acidic proteins localized in the secretory granules of a large variety of endocrine cells collectively named APUD cells (amine precursor uptake and decarboxylation). To examine the possible function of Cg/Sg as amine storage proteins, enteroendocrine cells of the rat gastric antral mucosa, i.e., serotonin-containing enterochromaffin (EC)-cells, gastrin (G)-, and somatostatin (D)-cells, were investigated immunohistochemically in serial semi-thin sections of controls and after intervention in serotonin synthesis. CgA and CgB immunoreactivity was determined semiquantitatively by optical density measurements. Experiments included inhibition of serotonin synthesis by p-chlorophenylalanine (pCPA), exogenous application of the serotonin precursor 5-hydroxytryptophan (5-HTP), and a combination of both treatments. The cellular distribution of Cg and the density of its immunoreactivity were closely related to the primary content of serotonin and the ability to store serotonin after 5-HTP application. Thus, Cg may act as amine-binding proteins in enteroendocrine cells, binding most probably being due to ionic interactions between Cg and the biogenic amines. EC- and G-cells, however, differed in their amine-handling properties and in the response of their Cg immunoreactivity after intervention in serotonin synthesis. We conclude, therefore, that the physiological function of Cg as amine storage proteins is restricted to endocrine cells with an endogenous content of amines. In other endocrine cells, exhibiting only a potential amine production, APUD may be considered as a kind of supravital staining without physiological significance.

[Clinical Feature in Infants of Breast Feeding Allergy and Its Possible Relation with Gastrointestinal Peptide Change in Breast Milk]

OBJECTIVES

To investigate clinical features in infants of breast milk allergy(BMA), and the possible relationship with the changes of somatostatin (SST) and motilin (MTL) in breast milk.

METHODS

Twenty three cases of pure breast feeding infants with allergic gastroenteritis were collected, while another 23 normal infants with pure breast feeding were enrolled as normal controls. Samples of infant stools and breast milk were collected for the measurement of SST and MTL levels detected by by radioimmunity.

RESULTS

The levels of SST and MTL in stool samples (pg/mg) were 32.6±8.9, 2.3±3.7 in BMA group and 56.2±12.7, 21.6±4.7 in normal control group, respectively. Those in breast milk (pg/mg) were 236.7±28.9, 159.4±36.7 in BMA group and 412.6±36.7, 216.8±59.7 in normal control group, respectively. All the differences were statistically significant ( P<0.05). In BMA infants, the clinical features were 91.3% (20/23) of diarrhea, 86.9% (21/23) of vomiting, 69.6% (16/23) of hematochezia, 95.7% (22/23) of C-reactive protein (CRP) increasing, 87.0% (20/23) of occult blood in stools, 73.9% (17/23) of neutrophil increasing, 39.1% (9/23) of WBC in stools.

CONCLUSIONS

For those infants of breast feeding with persisting and repeated gastrointestinal symptoms, allergy for breast milk should be considered. Deficiency of SST and MTL in breast milk may be a possible cause for food allergy.

Proteomics Suggests a Role for APC-Survivin in Response to Somatostatin Analog Treatment of Neuroendocrine Tumors

CONTEXT

Somatostatin analogs are established in the treatment of neuroendocrine tumors (NETs) including small intestinal NET; however, the molecular mechanisms are not well known. Here, we examined the direct effects of lanreotide in NET cell line models.

SETTING AND DESIGN

The cell lines HC45 and H727 were treated with 10nM lanreotide for different time periods and alterations of the proteome were analyzed by in-depth high-resolution isoelectric focusing tandem liquid chromatography-mass spectrometry. We next investigated whether the observed suppression of survivin was mediated by adenomatous polyposis coli (APC) and possible effects on tumor proliferation in vitro. Expression of survivin was assessed by immunohistochemistry in 112 NET cases and compared with patient outcome.

RESULTS

We quantified 6451 and 7801 proteins in HC45 and H727, respectively. After short time lanreotide treatment APC was increased and survivin reduced. Overexpression of APC in H727 cells decreased, and APC knock-down elevated the survivin level. The lanreotide regulation of APC-survivin could be suppressed by small interfering RNA against somatostatin receptor 2. Although lanreotide only gave slight inhibition of proliferation, targeting of survivin with the small molecule YM155 dramatically reduced proliferation. Moderate or high as compared with low or absent total survivin expression was associated with shorter progression-free survival, independent of tumor stage, grade, and localization.

CONCLUSIONS

We report a proteome-wide analysis of changes in response to lanreotide in NET cell lines. This analysis suggests a connection between somatostatin analog, APC, and survivin levels. Survivin is a possible prognostic factor and a new potential therapeutic target in NETs.

Growth Hormone and Insulin Signaling in Acromegaly: Impact of Surgery Versus Somatostatin Analog Treatment

CONTEXT

Somatostatin analogs (SAs) used in acromegaly to suppress GH secretion and tumor growth also suppress insulin secretion and may impact GH signaling.

OBJECTIVE

To compare GH and insulin signaling after iv GH exposure in acromegalic patients controlled by surgery (n = 9) or SA (n = 9).

DESIGN

Each patient was studied for 3 hours after an overnight fast (t = -60 to 120 minutes). GH was administered at t = 0 minutes; muscle and fat biopsies were obtained at t = 0 minutes and at t = 30 minutes (muscle) and t = 120 minutes (fat). Interstitial fluid was obtained from skin suction blisters (t = 0 minutes).

MAIN OUTCOME MEASURES

GH and insulin signalling in muscle and fat. GH and IGF-1 in serum and interstitial fluid; insulin and free fatty acids in serum.

RESULTS

The groups were comparable as regards GH and IGF-1. The SA group exhibited higher free fatty acid and glucose levels; basal suppressor of cytokine signaling protein 1 (SOCS1) mRNA in fat was increased in the SA group and correlated positively with SA dose (r² = 0.54; P = .04). GH-induced GH signalling (pSTAT5b) in muscle occurred in both groups together with increased expression of SOCS and CISH genes. GH-induced pAKTthr³⁰⁸ was observed in SA patients. In both groups, mRNA expression of phosphatase and tensin homolog, a suppressor of insulin signaling, increased in fat after GH.

CONCLUSION

1) Signatures of GH and insulin signaling differ as a function of acromegaly treatment modality. 2) Extra-pituitary effects of SA may account for this. 3) The clinical implications remain to be investigated.

Distribution of islet hormones in human adult pancreatic ducts

BACKGROUND/AIMS

The source of insulin-secreting cells from adult duct system is attractive, but its clinical practice remains poorly understood. Here, we aimed at identifying the distribution of secreted hormone reactive cells in adult ducts.

METHODS

Consecutive pancreatic slices from nondiabetic subjects were subjected to immunohistochemistry and immunofluorescence to screen islet hormones (insulin; glucagon, Glu; somatostatin, Som; pancreatic polypeptide, PP) and exocrine biomarkers (cytokeratin 19, CK19; chromogranin A, CgA; amylase). All pancreatic sections were imaged using an optical or confocal microscope.

RESULTS

Immunostaining results showed that insulin was expressed in adult ducts, in which the cell count was more than other islet hormone immunoactive cells. CK19-positive cells are mainly distributed in the ducts, whereas CgA-labeled cells are localized in endocrine cells. The duct branches visibly exhibited cell populations that co-expressed islet hormones in exocrine cell populations.

CONCLUSIONS

In this report, our findings demonstrate that adult ductal cells that produce insulin may contribute to beta-cell proliferation.

Endocrine cells in the ileum of patients with irritable bowel syndrome

AIM

To study the ileal endocrine cell types in irritable bowel syndrome (IBS) patients.

METHODS

Ninety-eight patients with IBS (77 females and 21 males; mean age 35 years, range 18-66 years) were included, of which 35 patients had diarrhea (IBS-D), 31 patients had a mixture of both diarrhea and constipation (IBS-M), and 32 patients had constipation (IBS-C) as the predominant symptoms. The controls were 38 subjects (26 females and 12 males; mean age 40 years, range 18-65 years) who had submitted to colonoscopy for the following reasons: gastrointestinal bleeding, where the source of bleeding was identified as hemorrhoids (n = 24) or angiodysplasia (n = 3), and health worries resulting from a relative being diagnosed with colon carcinoma (n = 11). The patients were asked to complete the: Birmingham IBS symptom questionnaire. Ileal biopsy specimens from all subjects were immunostained using the avidin-biotin-complex method for serotonin, peptide YY (PYY), pancreatic polypeptide (PP), enteroglucagon, and somatostatin cells. The cell densities were quantified by computerized image analysis, using Olympus cellSens imaging software.

RESULTS

The gender and age distributions did not differ significantly between the patients and the controls (P = 0.27 and P = 0.18, respectively). The total score of Birmingham IBS symptom questionnaire was 21 ± 0.8, and the three underlying dimensions: pain, diarrhea, and constipation were 7.2 ± 0.4, 6.6 ± 0.4, and 7.2 ± 0.4, respectively. The density of serotonin cells in the ileum was 40.6 ± 3.6 cells/mm² in the controls, and 11.5 ± 1.2, 10.7 ± 5.6, 10.0 ± 1.9, and 13.9 ± 1.4 cells/mm² in the all IBS patients (IBS-total), IBS-D, IBS-M, and IBS-C patients, respectively. The density in the controls differed significantly from those in the IBS-total, IBS-D, IBS-M, and IBS-C groups (P < 0.0001, P = 0.0001, P = 0.0001, and P < 0.0001, respectively). There was a significant inverse correlation between the serotonin cell density and the pain dimension of Birmingham IBS symptom questionnaire (r = -0.6, P = 0.0002). The density of PYY cells was 26.7 ± 1.6 cells/mm(2) in the controls, and 33.1 ± 1.4, 27.5 ± 1.4, 34.1 ± 2.5, and 41.7 ± 3.1 cells/mm² in the IBS-total, IBS-D, IBS-M, and IBS-C patients, respectively. This density differed significantly between patients with IBS-total and IBS-C and the controls (P = 0.03 and < 0.0001, respectively), but not between controls and, IBS-D, and IBS-M patients (P = 0.8, and P = 0.1, respectively). The density of PYY cells correlated significantly with the degree of constipation as recorded by the Birmingham IBS symptom questionnaire (r = 0.6, P = 0.0002). There were few PP-, enteroglucagon-, and somatostatin-immunoreactive cells in the biopsy material examined, which made it impossible to reliably quantify these cells.

CONCLUSION

The decrease of ileal serotonin cells is associated with the visceral hypersensitivity seen in all IBS subtypes. The increased density of PYY cells in IBS-C might contribute to the constipation experienced by these patients.

Influence of melatonin receptor signalling on parameters involved in blood glucose regulation

The pineal hormone melatonin is known to influence insulin secretion via the G-protein-coupled receptor isoforms MT1 and MT2. The present study was aimed to further elucide the impact of melatonin on blood glucose regulation. To this end, mouse lines were used, in which one of the two or both melatonin receptors were deleted. In comparison with wild-type mice of the same age (8-12 months old), increased plasma insulin and melatonin levels and decreased blood glucose levels and body weights were detected in the MT1- and double-knockout lines. The elimination of melatonin receptor signalling also altered blood glucose concentrations, body weight and melatonin and insulin levels when comparing wild-type and receptor knockout mice of different ages (6 wk and 8-12 months old); such changes, however, were dependent on the type of receptor deleted. Furthermore, reverse transcription polymerase chain reaction results provided evidence that melatonin receptor deficiency has an impact on transcript levels of pancreatic islet hormones as well as on pancreatic and hepatic glucose transporters (Glut1 and 2). Under stimulated insulin secretion in the presence of melatonin in the rat insulinoma β-cells INS-1, the Glut1 transcript level was decreased. In conclusion, the present findings demonstrate that melatonin receptor knockout types affect blood glucose levels, body weight, plasma levels of melatonin and insulin, as well as pancreatic hormone and Glut1 expression in significantly different manners.

Human islet mass, morphology, and survival after cryopreservation using the Edmonton protocol

The aim of this study was to assess recovery, cell death, and cell composition of post-thaw cultured human islets. Cryopreserved islets were provided by the Clinical Islet Transplant Program, Edmonton, Canada. Islets were processed using media prepared in accordance with Pre-Edmonton and Edmonton protocols. Cryopreserved islets were rapidly thawed and cultured for 24 h, 3 d, 5 d, and 7 d, following which they were processed for histology. Islet quantification, integrity, morphology and tissue turnover were studied via hematoxylin and eosin stained sections. Ultrastructure was studied by electron microscopy and endocrine cell composition by immunohistochemistry. Using the Pre-Edmonton protocol, islet recovery was 50.1% and islet survival was 50% at 24 h while for the Edmonton protocol, the islet recovery was 69.4% (p<0.001) and islet survival, 50% at ≈2.5 d. With an increasing culture duration although the physical integrity was retained there was an increasing loss of cohesivity both at light microscopic and at ultrastructure level regardless of the protocols used. Percentage islet survival and tissue turnover correlated negatively with culture duration in both protocols. The Edmonton protocol appears to preserve the islets better. However, culture duration adversely affects islet survival and quality, indicating the need for more optimal cryopreservation and culture techniques.

Targeted multiplex imaging mass spectrometry in transmission geometry for subcellular spatial resolution

Targeted multiplex imaging mass spectrometry utilizes several different antigen-specific primary antibodies, each directly labeled with a unique photocleavable mass tag, to detect multiple antigens in a single tissue section. Each photocleavable mass tag bound to an antibody has a unique molecular weight and can be readily ionized by laser desorption ionization mass spectrometry. This article describes a mass spectrometry method that allows imaging of targeted single cells within tissue using transmission geometry laser desorption ionization mass spectrometry. Transmission geometry focuses the laser beam on the back side of the tissue placed on a glass slide, providing a 2 μm diameter laser spot irradiating the biological specimen. This matrix-free method enables simultaneous localization at the sub-cellular level of multiple antigens using specific tagged antibodies. We have used this technology to visualize the co-expression of synaptophysin and two major hormones peptides, insulin and somatostatin, in duplex assays in beta and delta cells contained in a human pancreatic islet.

Synaptotagmin-2 is a reliable marker for parvalbumin positive inhibitory boutons in the mouse visual cortex

BACKGROUND

Inhibitory innervation by parvalbumin (PV) expressing interneurons has been implicated in the onset of the sensitive period of visual plasticity. Immunohistochemical analysis of the development and plasticity of these inhibitory inputs is difficult because PV expression is low in young animals and strongly influenced by neuronal activity. Moreover, the synaptic boutons that PV neurons form onto each other cannot be distinguished from the innervated cell bodies by immunostaining for this protein because it is present throughout the cells. These problems call for the availability of a synaptic, activity-independent marker for PV+ inhibitory boutons that is expressed before sensitive period onset. We investigated whether synaptotagmin-2 (Syt2) fulfills these properties in the visual cortex. Syt2 is a synaptic vesicle protein involved in fast Ca(2+) dependent neurotransmitter release. Its mRNA expression follows a pattern similar to that of PV throughout the brain and is present in 30-40% of hippocampal PV expressing basket cells. Up to now, no quantitative analyses of Syt2 expression in the visual cortex have been carried out.

METHODOLOGY/PRINCIPAL FINDINGS

We used immunohistochemistry to analyze colocalization of Syt2 with multiple interneuron markers including vesicular GABA transporter VGAT, calbindin, calretinin, somatostatin and PV in the primary visual cortex of mice during development and after dark-rearing.

CONCLUSIONS/SIGNIFICANCE

We show that in the adult visual cortex Syt2 is only found in inhibitory, VGAT positive boutons. Practically all Syt2 positive boutons also contain PV and vice versa. During development, Syt2 expression can be detected in synaptic boutons prior to PV and in contrast to PV expression, Syt2 is not down-regulated by dark-rearing. These properties of Syt2 make it an excellent marker for analyzing the development and plasticity of perisomatic inhibitory innervations onto both excitatory and inhibitory neurons in the visual cortex.

Immunocytochemical staining for islet amyloid polypeptide in pancreatic endocrine tumors

AIMS/HYPOTHESIS

Islet amyloid polypeptide is originally identified as the chief constituent of amyloid in insulinomas and type 2 diabetic islets. This study aimed to identify islet amyloid polypeptide by immunocytochemical staining in pancreatic endocrine tumors including 30 cases of insulinomas and non-β-cell pancreatic endocrine tumors.

RESULTS

In normal islets, 62% of islet cells and 52% of insulin cells were granularly positive for insulin and IAPP, respectively, with more insulin positive cells than IAPP positive cells and some densely positive staining for insulin and IAPP in irregularly shaped a nuclear, degenerating islet β-cells. In pancreatic endocrine tumors, all 10 insulinomas were positive for islet amyloid polypeptide but 2 glucogonomas, 1 somatostatinoma, 6 of 7 pancreatic polypeptidomas, all 7 gastrinomas and all 3 non-functioning pancreatic endocrine tumors were negative for islet amyloid polypeptide whereas one pancreatic polypeptidoma was positive for islet amyloid polypeptide.

METHODS

Using commercially available rabbit anti-islet amyloid polypeptide antibody, immunocytochemical staining was performed on 30 cases of pancreatic endocrine tumors, consisting of 10 insulinomas, 2 glucagonomas, 1 somatostatinoma, 7 pancreatic polypeptidomas, 7 gastrinomas and 3 non-functioning pancreatic endocrine tumors. Pancreatic tissues containing pancreatic endocrine tumors were systematically immunostained for insulin, glucagon, somatostatin, pancreatic polypeptide, gastrin and chromogranin A, in addition to islet amyloid polypeptide. When normal pancreatic tissues adjacent to pancreatic endocrine tumors were present, insulin, glucagon, somatostatin and islet amyloid polypeptide positive cells were counted for a total of 20 islets, which were divided into large islets and medium islets for each case.

CONCLUSIONS/INTERPRETATIONS

All 10 insulinomas and 1 pancreatic polypeptidoma were granularly positive for islet amyloid polypeptide, suggesting all 10 insulinomas contained enough insulin granules for IAPP whereas only one non-β-cell pancreatic endocrine tumor was co-localized with islet amyloid polypeptide in their secretary granules.

Analysis of the chemical coding of neurons in the intermediate thoracic ganglion of the pig

The pig has been widely used as a model in cardiovascular research. A unique feature of the porcine extrinsic sympathetic cardiac nerves is that they arise from intermediate ganglia in the thoracic cavity. The localization and pattern of distribution of nerve cell bodies and fibers containing tyrosine hydroxylase (TH), dopamine B-hydroxylase (DBH), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), somatostatin (SOM), galanin (GAL), methionine-enkephalin (MET) as well as calcitonin gene-related peptide (CGRP), substance P (SP) and pituitary adenylate cyclase-activating peptide (PACAP) was studied with immunohistochemistry. Almost all the neurons showed immunoreactivity to TH. Immunoreactivity to NPY, VIP, SOM, GAL, MET and PACAP was displayed by nerve cell bodies while nerve fibers exhibited immunoreactivity to all the neuropeptides studied. Therefore, it seems that the chemical coding of neurons and especially nerve fibers in the porcine intermediate ganglion share general similarities (with certain neurochemical variability), with porcine prevertebral ganglia (e.g., celiacomesenteric and caudal mesenteric ganglia).

Different secretory response of pancreatic isolated lobules and dissociated acini from hypothyroid rats to exogen TRH

This paper analyses the effect of hypothyroidism on pancreatic TRH and somatostatin concentrations, as well as the action of exogen TRH on pancreatic amylase secretion from isolated lobules and dissociated acini of both healthy and hypothyroid rats. In the hypothyroid group, pancreatic TRH and somatostatin increased. In the pancreatic lobules of untreated animals, bethanechol produced stimulatory action that was inhibited by TRH. On the other hand, lobules from hypothyroid rats did not respond to bethanechol stimulation. Acini amylase secretion after bethanechol stimulation was similar in both groups, although hypothyroid animals were more sensitive to the inhibitory effect of TRH. These findings suggest the existence of a factor blocking the amylase secretion in pancreatic lobules. This agent, probably TRH, could be eliminated in the experimental model of dissociated acini.

Morphometric and immunohistochemical study on the endocrine cells of pancreatic transplants

The endocrine cells of embryonic pancreatic tissue fragments transplanted into the anterior eye-chamber of rats for 74 days were investigated immunohistochemically and morphometrically and the results obtained were compared with that of normal tissue. Four types of endocrine cells were identified and their distribution was as follows: insulin: 42-52%, glucagon: 11-28%, somatostatin: 4%, and pancreatic polypeptide-positive cells: 3-6%. Their size in square micrometer were as follows: 153, 110, 38 and 51. The area, number, distribution and topography of these endocrine cells with regard to each other did not differ significantly from that of normal tissue. The area of each islet and their cell population vary considerably both in normal and transplanted pancreas.

Changes in tissue levels of growth hormone, insulin-like growth factor-I, and somatostatin in the femurs of hind-limb immobilized rats

Immobilization of an extremity causes skeletal muscle atrophy and a dramatic increase in bone resorption. Growth hormone (GH) is known to play an important role in bone remodeling mediated in part by local insulin-like growth factor-I (IGF-I). In this study, we investigated changes in the levels of GH and IGF-I peptide in bone extracts from the femur after hind-limb immobilization for 5 days, 2, 4, and 8 weeks. The levels of somatostatin, which interacts with GH, were also measured in the bone extracts. GH levels increased after 8 weeks of hind-limb immobilization whereas the IGF-I concentrations increased after 2 weeks, but returned to control levels at 4 weeks, and decreased after 8 weeks of immobilization. The somatostatin levels in the bone extracts increased only after 8 weeks of hind-limb immobilization. Our findings suggest that, after hind-limb immobilization, changes in the concentrations of GH, IGF-I, and somatostatin in bone may mediate bone resorption either directly or through interaction with other factors.

[Effect of "Xiusanzhen" on learning-memory ability and hippocampal somatostatin and arginine vesopressin contents in vascular dementia rats]

OBJECTIVE

To observe the effect of electroacupuncture (EA) of "Xiusanzhen" [bilateral "Yingxiang" (LI 20) + "Yintang" (GV 29)] on learning-memory ability and hippocampal somatostatin (SS) and arginine vasopressin (AVP) contents in vascular dementia (VD) rats.

METHODS

Forty SD rats were randomly divided into control, VD model, VD plus olfactory bulb lesion (OBL, destroyed by electro-coagulation) and EA groups, with 10 cases in each. VD model was established by 4-vessel occlusion. Morris maze tests were conducted for evaluating the rats' learning and memory ability. EA (1-3 mA, 80/100 Hz) was applied to bilateral LI 20 and GV 29 in VD + OBL and EA groups for 10 min, once daily (except Saturdays and Sundays) for 6 weeks. The contents of SS and AVP in hippocampus tissue were measured by radioimmunoassay.

RESULTS

In comparison with control group, the average escape latency (AEL) prolonged significantly and the target-platform crossing times (TPCT) decreased remarkably in VD model group (P < 0.01). In comparison with VD model group, the AEL was shortened and TPCT increased remarkably in EA group (P < 0.01). No significant differences were found between VD model and VD + OBL groups in the AEL and the TPCT (P > 0.05). Hippocampal SS and AVP contents in VD model group were significantly lower than those in control group (P < 0.05), while those in EA group were markedly higher than those in VD model group (P < 0.05). No significant differences were found between VD model and VD + OBL groups in SS and AVP contents (P > 0.05).

CONCLUSION

EA of "Xiusanzhen" can improve VD rats' learning-memory ability, which may be related to its effects in raising hippocampal SS and AVP contents and to the intact olfactory pathway.

Analysis of pancreas tissue in a child positive for islet cell antibodies

AIMS/HYPOTHESIS

Type 1 diabetes is caused by an immune-mediated process, reflected by the appearance of autoantibodies against pancreatic islets in the peripheral circulation. Detection of multiple autoantibodies predicts the development of diabetes, while positivity for a single autoantibody is a poor prognostic marker. The present study assesses whether positivity for a single autoantibody correlates with pathological changes in the pancreas.

METHODS

We studied post mortem pancreatic tissue of a child who repeatedly tested positive for islet cell antibodies (ICA) in serial measurements. Paraffin sections were stained with antibodies specific for insulin, glucagon, somatostatin, interferon alpha, CD3, CD68, cyclooxygenase-2 (COX-2), beta-2-microglobulin, coxsackie B and adenovirus receptor (CAR), natural killer and dendritic cells. Apoptosis was detected using Fas-specific antibody and TUNEL assay. Enterovirus was searched for using immunohistochemistry and in situ hybridisation, as well as enterovirus-specific RT-PCR from serum samples.

RESULTS

The structure of the pancreas did not differ from normal. The number of beta cells was not reduced and no signs of insulitis were observed. Beta-2-microglobulin and CAR were strongly produced in the islets, but not in the exocrine pancreas. Enterovirus protein was detected selectively in the islets by two enterovirus-specific antibodies, but viral RNA was not found.

CONCLUSIONS/INTERPRETATION

These observations suggest that positivity for ICA alone, even when lasting for more than 1 year, is not associated with inflammatory changes in the islets. However, it is most likely that the pancreatic islets were infected by an enterovirus in this child.

Control of IGF-I levels with titrated dosing of lanreotide Autogel over 48 weeks in patients with acromegaly

BACKGROUND

An essential criterion for control of acromegaly is normalization of IGF-I levels. Somatostatin analogues act to suppress IGF-I and GH levels.

OBJECTIVE

To assess the efficacy and safety of 48 weeks titrated dosing of lanreotide Autogel.

DESIGN

Open-label, multicentre, phase III, 48-week trial.

METHODS

Patients with active acromegaly (IGF-I levels > 1.3 times upper limit of age-adjusted normal range) were recruited. Twelve injections of lanreotide Autogel were given at 28-day intervals: during the 16-week fixed-dose phase, patients received 90 mg; in the 32-week dose-titration phase, patients received 60, 90 or 120 mg according to GH and IGF-I levels. Intention-to-treat analysis was performed to determine the proportion of patients with normalized age-adjusted IGF-I levels at study end. Secondary evaluations included GH levels, clinical acromegaly signs and safety.

RESULTS

Fifty-seven of 63 patients completed the study. Lanreotide Autogel resulted in normalized age-adjusted IGF-I levels in 27 patients (43%, 95% CI 31-55). Mean GH levels decreased from 6.2 to 1.5 microg/l at study end, with 53 of 62 patients (85%) having GH levels < or = 2.5 microg/l (95% CI 76.7-94.3) and 28 of 62 patients (45%) with levels < 1 microg/l (95% CI 32.8-57.6). Twenty-four (38%) had both normal IGF-I levels and GH levels < or = 2.5 microg/l. Acromegaly symptoms reduced significantly in most patients throughout the study. The most common adverse events were gastrointestinal, as expected for somatostatin analogues.

CONCLUSIONS

Using IGF-I as primary end-point, 48 weeks lanreotide Autogel treatment, titrated for optimal hormonal control, controlled IGF-I and GH levels effectively, reduced acromegaly symptoms and was well tolerated.

[Effects of electroacupuncture on plasma and cerebral somatostatin and beta-EP contents and learning-memory ability in vascular dementia rats]

OBJECTIVE

To observe the effect of electroacupuncture (EA) on learning-memory ability of vascular dementia (VD) rats, and the simultaneous changes of plasma and cerebral somatostatin (SS) and beta-endorphin (EP) contents.

METHODS

Forty-one SD rats were randomly divided into control (n=8), model A (n=8, no treatment) and B (n=8, intragastric perfusion of 15% saline), EA (n=9) and medication (n=8, intragastric perfusion of Nimoldipine, 12 mg/kg) groups. VD model was established by using modified 4-vessels occlusion method. EA (150 Hz, 1-2 mA) was applied to "Baihui" (GV 20), "Dazhui" (DU 14), "Pishu" (BL 20) and "Shenshu" (BL 23) for 20 min, once daily for 15 days. Morris water maze tests were conducted for evaluating the rats' learning-memory ability. The contents of SS and beta-EP in plasma and brain tissue were measured by radioimmunoassay (RIA).

RESULTS

In comparison with sham-operation group, the escape latency (EL) prolonged significantly and the target-platform crossing times decreased remarkably (P<0.01) in model group B. In comparison with model group B, EL shortened and target-platform crossing times increased both significantly in EA and medication groups (P<0.01). Plasma and cerebral SS, and cerebral beta-EP contents of model groups A and B were significantly lower than those of sham-operation group(P<0.01), while plasma beta-EP level had no obvious change (P>0.05). Plasma and cerebral SS, and cerebral beta-EP contents in both EA and medication groups were considerably higher than those in model groups A and B (P<0.01). No significant differences were found between EA and medication groups in EL, target-platform crossing times, plasma and cerebral SS and beta-EP levels, and between model group A and model group B in plasma and cerebral SS and beta-EP levels (P>0.05).

CONCLUSION

EA can raise plasma and cerebral SS and cerebral beta-EP levels, and improve the learning-memory ability in VD rats.

Rat pancreatic islet size standardization by the "hanging drop" technique

INTRODUCTION

Rejection and hypoxia are the main factors that limit islet engraftment in the recipient liver in the immediate posttransplant period. Recently authors have reported a negative relationship of graft function and islet size, concluding that small islets are superior to large islets. Islets can be dissociated into single cells and reaggregated into so called "pseudoislets," which are functionally equivalent to intact islets but exhibit reduced immunogenicity. The aim of our study was develop a technique that enabled one to obtain pseudoislets of defined, preferably small, dimensions.

MATERIALS AND METHODS

Islets were harvested from Lewis rats by the collagenase digestion procedure. After purification, the isolated islets were dissociated into single cells by trypsin digestion. Fractions with different cell numbers were seeded into single drops onto cell culture dishes, which were inverted and incubated for 5 to 8 days under cell culture conditions. Newly formed pseudoislets were analyzed for dimension, morphology, and cellular composition.

RESULTS

The volume of reaggregated pseudoislets strongly correlated with the cell number (r(2) = .995). The average diameter of a 250-cell aggregate was 95 +/- 8 microm (mean +/- SD) compared with 122 +/- 46 microm of freshly isolated islets. Islet cell loss may be minimized by performing reaggregation in the presence of medium glucose (11 mmol/L) and the GLP-1 analogue Exendin-4. Morphology, cellular composition, and architecture of reaggregated islets were comparable to intact islets.

CONCLUSION

The "hanging drop" culture method allowed us to obtain pseudoislets of standardized size and regular shape, which did not differ from intact islets in terms of cellular composition or architecture. Further investigations are required to minimize cell loss and test in vivo function of transplanted pseudoislets.

Distribution of neuroendocrine cells in the small and large intestines of the one-humped camel (Camelus dromedarius)

The distribution and relative frequency of neuroendocrine cells in the small and large intestines of one-humped camel were studied using antisera against 5-hydroxytryptamine (5-HT), cholecystokinin (CCK-8), somatostatin (SOM), peptide tyrosine tyrosine (PYY), gastric inhibitory polypeptide (GIP), neuronal nitric oxide synthase (nNOS), gastrin releasing peptide (GRP), substance P (SP), and neurokinin A (NKA). Among these cell types, CCK-8 immunoreactive (IR) cells were uniformly distributed in the mucosa, while others showed varied distribution in the villi or crypts of the small intestine. Immunoreactive cells like 5HT, CCK-8, and SOM showed peak density in the villi and crypts of the small intestine and in the colonic glands of the large intestine, while cells containing SP were discerned predominately in the crypts. 5-HT, CCK-8 and SOM cells were mainly flask-shaped and of the open-variety, while PYY and SP immunoreactive cells were mainly rounded or basket-shaped and of the closed variety. Basically the distribution pattern of the endocrine cells in the duodenum, jejunum and colon of the one-humped camel is similar to that of other mammals. Finally, the distribution of these bioactive agents may give clues as to how these agents aid in the function of the intestinal tract of this desert animal.

An immunohistochemical study of endocrine cells in the stomach of hypertensive rats

Essential hypertension is a complex disease with both genetic and environmental determinants. The effect of spontaneous hypertension on the distribution and occurrence of somatostatin-, gastrin- and serotonin-immunoreactive cells in the fundus and pylorus of the rat stomach was examined by immunohistochemistry. The animals were killed by decapitation at 4 and 16 weeks of age (5 control rats and 5 hypertensive rats). Endocrine cells generally increase in number in hypertensive rats as compared to control rats. However, the detailed responses of endocrine cells to hypertension depend on the cell type, region of gastric mucosa and age of animals. The present results suggest that hypertension has an influence on the intrinsic regulatory system by endocrine cells control in the rat stomach.

Noninsulinoma pancreatogenous hypoglycemia syndrome: quantitative and immunohistochemical analyses of islet cells for insulin, glucagon, somatostatin, and pancreatic and duodenal homeobox protein

OBJECTIVE

To present a case of an elderly man with noninsulinoma pancreatogenous hypoglycemia syndrome (NIPHS) and to determine the pathogenesis of this syndrome.

METHODS

The pancreas of our patient with NIPHS was immunocytochemically stained for insulin-, glucagon-, and somatostatin-secreting cells and pancreatic and duodenal homeobox protein (PDX-1). The clinical findings and morphologic and immunocytochemical analyses of the islets of our patient are described, along with a review of related published reports.

RESULTS

A 78-year-old man presented with hyperinsulinemic hypoglycemia, with episodes unrelated to meals or fasting. An insulinoma could not be localized by preoperative imaging or by intraoperative ultrasonography or palpation. He underwent a 70% distal pancreatectomy. For assessment of the possibility that a nuclear transcription factor regulating islet beta-cell growth and development is overexpressed in this disease and is responsible for diffuse islet hyperfunction and proliferation of beta-cells, pancreatic sections from our patient were stained immunocytochemically for PDX-1, insulin, glucagon, and somatostatin. Morphologic findings were compared with pancreatic sections from normal control patients and normative data reported in the literature. Clinical findings and morphologic analyses were consistent with NIPHS. Islets were arranged in long clusters, both in the pancreatic tissue and in peripancreatic adipose tissue. Islets were small but increased in number, and insulin, glucagon, and somatostatin were present in the islets. The relative intensity of insulin staining was increased in our patient in comparison with that in the control patients, and PDX-1 was not overexpressed.

CONCLUSION

The etiopathogenesis of NIPHS in this patient involved (1) an increased number of islets with development of ectopic islets in the peripancreatic adipose tissue; (2) alpha- and delta- as well as beta-cell proliferation; and (3) an early step in the development of the islet not involving overexpression of PDX-1.

[Diagnostics and treatment of neuroendocrine tumors of the digestive tract in the light of the present standards]

Neuroendocrine tumors (NET) constitute 0.5% of all cancers appearing at the man and 2% of all tumors of the digestive tract. They constitute 70% of all NET i.e., of tumors coming from endocrine cells dispersed in the entire body of the man, creating diffuse endocrine system (DES). It is estimated that the incidence of gastroenteropatic neuroendocrine tumors (GEP) is about 3 cases/year/100000 inhabitants. The characteristic feature of these tumors is that they have the ability to produce, store and secrete peptic hormones and biogenic amines. These substances are evoking characteristic symptoms which let suspect the development of certain diseases by their influence on the human organism. Little percentage of tumors coming from cells of the endocrine system does not secrete characteristic substances - these are so-called tumors hormonaly non active. The purpose of the work is to pay attention to the diagnostic-therapeutic possibility associated with the progress of medical sciences which let more frequent recognizing and more effective treatment hence the improvement of prognosis of a sick patient with GEP. In the work, I will introduce characteristics of individual GEP tumors associated with peculiar signs and diagnostic and therapeutic possibilities. In the case of neuroendocrine tumor suspection the determination made of unique and nonunique markers NET should be directed. The attempt to localise changes is based on scintigraphy with using somatostatin analogues, endoscopic ultrasonography, the computer tomography, the magnetic resonance and positron emission tomography The histopathological examination carried out on the base of guidelines of the World Health Organization from 2000 which assembly anatomical, clinical- pathological and functional features of the tumor which let making conclusive diagnosis. In the case of the GEP diagnosis, the procedure by choice is surgical treatment which, however, as a result of its high level of advancement, is often nonradical and must be completed with pharmacological treatment. As a completing treatment, analogues of somatostatin, "interferon alpha", chemotherapy and radioisotope treatment based on marked analogues of the somatostatin receptor are used. The analysis of the documentationon GEP NET tumors permits to notice that the advanced knowledge of clinical symptoms accompanying certain tumors appropriate analysis of the laboratory tests, accurate using imaging diagnostics and the cooperation with a good patomorfological centre can increase our effectiveness in recognizing and curing GEP NET tumors and, what is more, it could increase survival and improve our patients' standard of living. What is even more essential is that the majority of them is reporting to us in the moment of the appearance of complications such as the obstruction of the digestive tract, the obstructive jaundice, nonunique pain complaints of the abdominal cavity. GEP NET tumors are another group of diseases requiring the interdisciplinary approach of many specialists to a patient-gastroenterologists, endocrinologists, radiologists, surgeons, specialists of nuclear medicine and chemotherapy

Chemical coding of submucosal type V neurons in porcine ileum

In this study, we attempted to determine the proportion of type V neurons relative to the putative whole neuron population in the two submucosal plexuses of pigs identified by their neurofilament immunoreactivity. The total neuron number was estimated in cuprolinic blue (CB)/anti-Hu protein (HU) costained wholemounts as the sum of the number of CB+/HU+, CB+/HU- and CB-/HU+ neurons. In the external submucosal plexus (ESP), HU labelled 98.6% and CB 97.3% of neurons. In the internal submucosal plexus, HU labelled 98.3%, whereas CB only marked 92.5% of neurons. Furthermore, we investigated the chemical coding of submucosal type V neurons and searched for submucosal, non-type V neurons displaying the same chemical coding as the myenteric type V neurons described earlier, i.e. the colocalization of calcitonin gene-related peptide (CGRP) and somatostatin (SOM). In order to facilitate immunohistochemical detection of neuroactive peptides, ileal segments were pretreated with colchicine prior to fixation. Type V neurons in the ESP occurred either as single cells displaying one or few prominent dendrite(s) or within aggregates displaying a dendritic tangle. In this plexus, type V neurons amounted to between 0.9 and 1.6% of all CB-stained neurons. ESP type V neurons displayed immunoreactivities for choline acetyl transferase (95.8%) and leucine-enkephalin (73.9%). All type V neurons were negative for neuronal nitric oxide synthase. Fifty-eight percent of ESP CGRP/SOM co-immunoreactive neurons displayed type V morphology, whereas 42% were non-type V neurons. Thus, the chemical coding of ESP type V neurons is in principal similar to that of the myenteric type V neurons described earlier. In the internal submucosal plexus, we found no type V neurons. In this plexus, 0.2% of all neurons counterstained with HU displayed CGRP/SOM coreactivity. As had been observed earlier concerning the myenteric type V neurons, ESP type V neurons were also closely apposed by conspicuous accumulations of boutons reactive for the same markers as the neurons themselves. Although we cannot exclude that axons of CGRP/SOM-reactive enteric, non-type V or extrinsic neurons end synaptically on type V neurons, we suggest that the main synaptic input to type V neurons originates from other type V neurons. This presents an argument for an interneuronal role of type V neurons.

Ontogenesis of human cerebellar cortex and biopathological characterization in sudden unexplained fetal and infant death

The aims of this study were to investigate in the human cerebellar cortex the structural and biological ontogenetic features, the possible presence of alterations in cases of sudden unexplained fetal and infant death, and the involvement of the maternal cigarette smoking in developmental abnormalities. We analyzed 52 brains of fetal and infant death victims, aged from the second gestational trimester to 12th postnatal month. In the cerebellar cortex we evaluated, besides the morphological aspects, the expression of several biomarkers implicated in proliferative processes (c-fos, proliferating cell nuclear antigen, and apoptosis) as well as the presence of the neurotransmitter somatostatin, which is strongly implicated in central nervous system differentiation, and of EN2 gene. The observed features of the cerebellar cortex, mainly confined to the transient external granular layer, were high proliferative activity and high expression of both somatostatin and EN2 gene in prenatal life and high apoptotic index after birth. In 41% of the sudden unexplained death victims, in the greater part with smoking mothers, we observed different biopathological alterations of the cerebellar cortex. Maternal smoking is increasingly being demonstrated to be one of the main contributors to developmental neurological alterations in the offspring.

[Clinicopharmacological study of gastrointestinal drugs from the viewpoint of postmarketing development]

Pharmaceutical development starts with the discovery of a new compound. Drugs become commercially available after non-clinical and clinical studies, but processes that take place after marketing are also important for pharmaceutical development. In recent years, use of the phrase "Ikuyaku" meaning postmarketing development has become more common. Sometimes, the proper usage, indications and harmful effects of a drug are discovered only after it becomes commercially available and is administered to many patients. Hence, pharmacists need to actively perform postmarketing studies to reveal the true nature of drugs. In the present clinicopharmacological study, we investigated the effects of histamine H(2) receptor antagonists (H(2)-RAs) on the plasma concentrations of gastrointestinal peptides from the viewpoint of postmarketing development. First we established an enzyme immunoassay for secretin, which is involved in gastrointestinal motility. Then we used this and existing peptide assays to investigate the above-mentioned issues. Ranitidine and nizatidine increased the plasma concentration of motilin. It is believed that the plasma concentration of Ach is elevated by ranitidine and nizatidine, which possesses an anti-AchE activity, and that the increased the plasma concentration of Ach facilitated release of motilin, elevating the plasma concentration of motilin. When compared to the placebo, lafutidine significantly increased the plasma concentration of CGRP (calcitonin gene-related peptide) and substance P. Furthermore, released CGRP stimulated CGRP1 receptors to facilitate secretion of somatostatin. Therefore, lafutidine appears to protect the gastric mucosa and regulate gastrointestinal motility. The same results were obtained with ranitidine and nizatidine. While H(2)-RAs have a common function in suppressing the secretion of gastric acid, they do not exhibit the same effects on factors related to recurrence of peptic ulcer, such as gastrointestinal motility and blood flow in the gastrointestinal mucosa. Hence, measuring the plasma concentration of gastrointestinal peptides can be used to estimate the effects of drugs on gastrointestinal motility. From the viewpoint of postmarketing development, we are in the process of establishing indicators for the proper usage of pharmaceutical drugs. Pharmacists need to closely follow and monitor adverse reactions. In order to further improve monitoring of drug therapy, it will be necessary to assess not only the blood concentrations of drugs, but also biological reactions to the drugs. Since the levels of peptides reflect the clinical efficacy of gastrointestinal drugs, measuring peptide levels appears to be useful for selecting appropriate drugs.

Ontogeny of the endocrine pancreatic cells of the gilthead sea bream, Sparus aurata (Teleost)

The development of the gilthead sea bream, Sparus aurata, endocrine pancreas was studied from hatching to 114 days, using immunocytochemical techniques. Bonito insulin (INS)-, synthetic somatostatin-14 (SS-14)-, salmon somatostatin-25 (SS-25)-, mammalian somatostatin-28 (1-12) (SS-28)-, porcine glucagon (GLU)-, glucagon-like peptide-1 (1-19) (GLP-1)-, synthetic porcine peptide tyrosine tyrosine (PYY)-, and neuropeptide Y (NPY)-like immunoreactivities were demonstrated. The different types of endocrine cells appear at distinct stages of development and differ in their arrangement. The coexistence of INS and SS-25 immunoreactivities was demonstrated in the cells of one strand or primordial cord and a primordial islet that appeared close to the dorsal epithelium of the anterior region of the undifferentiated gut or next to the gut at hatching and one day after hatching, respectively. INS- and SS-25- immunoreactive (ir) cells were located in the core and at the periphery of the single islet found in 2-day-old larvae, while SS-28-ir cells were found in the single islet in 4- to 11-day-old larvae. GLU/GLP-1-ir cells were located next to the outer SS-25-ir cells in the single islet of 12- and 16-day-old larvae. SS-14/SS-25- and SS-14/SS-28-ir cells were detected in the outer region and in the inner area of the single islet, respectively, in 17- to 23-day-old larvae. One big islet and several small islets and isolated or clustered cells next to the pancreatic duct were present in 24- and 25-day-old larvae. The islets were similar in cell composition to the single islet seen in the previous stage, while the isolated and grouped cells showed the coexistence of INS and diverse SSs immunoreactivities. Nerve fibers showing PYY immunoreactivity were identified in the islets from 17 days onwards. In 30- to 44-day-old larvae, GLU and NPY immunoreactivities coexisted in a few cells at the periphery of some small islets. PYY-ir cells were first detected at day 51. One big islet, several intermediate islets and numerous small islets were present from 51-day-old-larvae to juveniles. GLU was colocalized with PYY and NPY in a few cells in a small peripheral area in the big islet and a few intermediate islets. The outer region of small islets and other intermediate islets showed the complete coexistence of GLU, PYY, and NPY.

The superior colliculus of the camel: a neuronal-specific nuclear protein (NeuN) and neuropeptide study

In this study we examined the superior colliculus of the midbrain of the one-humped (dromedary) camel, Camelus dromedarius, using Nissl staining and anti-neuronal-specific nuclear protein (NeuN) immunohistochemistry for total neuronal population as well as for the enkephalins, somatostatin (SOM) and substance P (SP). It was found that, unlike in most mammals, the superior colliculus is much larger than the inferior colliculus. The superior colliculus is concerned with visual reflexes and the co-ordination of head, neck and eye movements, which are certainly of importance to this animal with large eyes, head and neck, and apparently good vision. The basic neuronal architecture and lamination of the superior colliculus are similar to that in other mammals. However, we describe for the first time an unusually large content of neurons in the superior colliculus with strong immunoreactivity for met-enkephalin, an endogenous opioid. We classified the majority of these neurons as small (perimeters of 40-50 microm), and localized diffusely throughout the superficial grey and stratum opticum. In addition, large pyramidal-like neurons with perimeters of 100 microm and above were present in the intermediate grey layer. Large unipolar cells were located immediately dorsal to the deep grey layer. By contrast, small neurons (perimeters of 40-50 microm) immunopositive to SOM and SP were located exclusively in the superficial grey layer. We propose that this system may be associated with a pain-inhibiting pathway that has been described from the periaqueductal grey matter, juxtaposing the deep layers of the superior colliculus, to the lower brainstem and spinal cord. Such pain inhibition could be important in relation to the camel's life in the harsh environment of its native deserts, often living in very high temperatures with no shade and a diet consisting largely of thorny branches.

Role for the subthreshold currents ILeak and IH in the homeostatic control of excitability in neocortical somatostatin-positive inhibitory neurons

Cortical circuitry reconfigures in response to chronic (1-3 days) changes in activity levels. To understand this process, we must know the role played by inhibitory neurons because they crucially influence network properties by controlling action potential generation and synaptic integration. Using pharmacological blockade of activity in neocortical organotypic slice cultures, we examined the activity-dependent regulation of membrane excitability in a specific inhibitory neuron subtype: the somatostatin-positive (SOM+) neuron. Chronic action potential blockade (TTX, 2.5 days) resulted in increased excitability in SOM+ neurons. This result is consistent with a homeostatic process to maintain the average firing rate of SOM+ neurons at a particular level. Excitability changes were not ascribed to changing cell size or alterations in voltage-dependent sodium current. Instead, the excitability increase was largely the result of a decrease in the density of two subthreshold currents: a passive leak current (ILeak) and H-current (IH). The downregulation of these currents increased excitability mostly through a decrease in membrane input conductance. The coadaptation of ILeak and IH enabled a change in input conductance while helping to preserve membrane potential. Evidence indicated that ILeak was probably mainly mediated by K+. At earlier culture ages, this adaptation was superimposed on developmental changes, whereas at older ages, the same types of induced alterations occurred but with no developmental component. Together with other studies, these data indicate that both inhibitory and excitatory neurons increase membrane excitability with chronic reduction in activity, but through different mechanisms.

Assay of gastrin and somatostatin in gastric antrum tissues of children with chronic gastritis and duodenal ulcer

AIM: To study the expressions of gastrin (GAS) and somatostatin (SS) in gastric antrum tissues of children with chronic gastritis and duodenal ulcer and their role in pathogenic mechanism.

METHODS: Specimens of gastric antrum mucosa from 83 children were retrospectively analyzed. Expressions of GAS and SS in gastric antrum tissues were assayed by the immunohistochemical En Vision method.

RESULTS: The expressions of GAS in chronic gastritis Hp+ group (group A), chronic gastritis Hp- group (group B), the duodenal ulcer Hp + group (group C), duodenal ulcer Hp- group (group D), and normal control group (group E) were 28.50 + 4.55, 19.60 + 2.49, 22.69 + 2.71, 25.33 + 4.76, and 18.80 + 2.36, respectively. The value in groups A-D was higher than that in group E. The difference was not statistically significant. The expressions of SS in groups A-E were 15.47 + 1.44, 17.29 + 2.04, 15.30 + 1.38, 13.11 + 0.93 and 12.14 + 1.68, respectively. The value in groups A-D was higher than that in group E. The difference was also not statistically significant.

CONCLUSION: The expressions of GAS and SS are increased in children with chronic gastritis and duodenal ulcer.

Uterine Cervical Afferents in Thoracolumbar Dorsal Root Ganglia Express Transient Receptor Potential Vanilloid Type 1 Channel and Calcitonin Gene–related Peptide, but Not P2X3 Receptor and Somatostatin

Background

Little is known regarding the phenotype of afferents that innervate the uterine cervix. Chronic estrogen sensitizes uterine cervical afferents to mechanical distension, but whether this reflects changes in afferent neurotransmitter or excitatory ion channel expression is unknown. The authors used immunocytochemistry to characterize uterine cervical afferents and the effects of estrogen on them.

Methods

Fluorogold was injected into the uterine cervix of intact rats (n = 7) and those with ovariectomy alone (n = 9) or with estrogen supplementation (n = 8). Bilateral dorsal root ganglia at T12-L2 were removed and immunostained for transient receptor potential vanilloid type 1 (TRPV1), P2X3 receptor, calcitonin gene-related peptide, and somatostatin. The proportion of fluorogold-traced dorsal root ganglion neurons expressing each of these markers was compared with untraced neurons.

Results

Most fluorogold-traced cells were found at L1 (&gt; 55%) and were of small diameter (24 microm). TRPV1 expression was similar between traced and untraced cells, except the estrogen treatment increased TRPV1 expression in traced cells. Calcitonin gene-related peptide expression was greater in traced than in untraced cells, with no effect of experimental treatment. No traced cells expressed the P2X3 receptor or somatostatin, although each of these was present in untraced cells.

Conclusion

Uterine cervical afferents in the hypogastric nerve express TRPV1, an important nociceptive channel, which may play a role in estrogen-induced sensitization of cervical afferents. High expression of calcitonin gene-related peptide suggests a sensory and efferent role for this peptide. In contrast to other viscera, these afferents do not express somatostatin or P2X3 receptor, indicating a unique phenotype of these C fibers.

Forkhead transcription factor FOXO1A is critical for induction of human decidualization

Experiments utilizing RNA interference technology were performed to determine whether the forkhead transcription factor FOXO1A, a member of the FOXO family of proteins, plays a critical role in the induction of human uterine decidualization. Human decidual fibroblast cells were decidualized in vitro for 6 days with medroxyprogester-one, estradiol, and dibutyryl cAMP in the presence or absence of a highly specific FOXO1A small interfering RNA (siRNA) that inhibits FOXO1A mRNA and protein expression by more than 80%. RNA and proteins were extracted from the cells at 0, 2, 4, and 6 days. FOXO1A and IGFBP-1 proteins were determined by immunoblotting; and intracellular mRNA levels for several decidualization marker genes were determined by real-time PCR. Exposure of the cells to FOXO1A siRNA in five separate experiments resulted in a 40-75% inhibition of prolactin, IGFBP-1, tissue inhibitor of metalloproteinase 3 (TIMP3), somatostatin and endometrial bleeding-associated factor (EBAF) mRNAs, all of which are markedly induced during the decidualization process. In contrast, actin and GAPDH mRNA levels did not change during decidualization. The inhibition of mRNA levels was first noted at day 2 and persisted for the remainder of each experiment. Western blot analysis indicated that the FOXO1A siRNA inhibited IGFBP-1 protein expression by 60-80%. Decidual fibroblast cells exposed in an identical manner to a control RNA that had no effect on FOXO1A expression caused only a 0-15% inhibition of the marker genes and IGFBP-1 protein. Taken together, these findings strongly suggest a critical role for FOXO1A in the induction of human decidualization.

Involvement of brain-derived neurotrophic factor in the regulation of hypothalamic somatostatin in vivo

Brain-derived neurotrophic factor (BDNF) has been extensively studied in the central nervous system as a survival and differentiation factor and in plasticity processes. In vitro, BDNF has been shown to stimulate cellular differentiation and neurohormones synthesis and release. We demonstrated that BDNF is a potent and specific stimulatory agent of somatostatin (SRIH) synthesis in primary cultures of hypothalamic neurons. However, less information is available about its function on SRIH neurons in vivo. In the present study, we examined the effect of in vivo intracerebroventricular BDNF administration in adult non-anesthetized male rats. Two distinct experimental approaches were used: acute intracerebroventricular injection and long-term (14 days) continuous infusion (Alzet micro-pumps). We demonstrate that single intracerebroventricular BDNF injections (5 microg/rat) induce an early (60 and 180 min) decrease in the SRIH mRNA signal in the hypothalamic periventricular nucleus (PeVN) accompanied by a decrease of the hypothalamic SRIH content. 48 h after the acute injection, SRIH mRNA levels and peptide content strongly and significantly increased. After continuous intracerebroventricular BDNF administration (12 microg/day for 14 days), a significant increase in the SRIH hypothalamic content was observed. Nevertheless, the increase in peptide content was not correlated with a similar increase in the PeVN messenger level. These findings show the involvement of BDNF in the in vivo regulation of somatostatinergic neurons in adult rats, which clearly differs according to the BDNF administration mode.

Distribution of somatostatin immunoreactivity in the brain of the snake Bothrops jararaca

The distribution of perikarya and fibers containing somatostatin was studied in the brain of the snake Bothrops jararaca by means of immunohistochemistry using an antiserum against synthetic somatostatin. Immunoreactive perikarya and fibers were localized in telencephalic, diencephalic and mesencephalic areas. In the telencephalon, numerous immunoreactive perikarya were found in the medial, dorsomedial, dorsal and lateral cortex, mainly in the deep plexiform layer, less so in the cellular layer, but not in the superficial plexiform layer. Immunoreactive perikarya were also observed in the dorsal ventricular ridge, the nucleus of the diagonal band of Broca, amygdaloid complex, septum and lamina terminalis. In the diencephalon, labelled cells were observed in the paraventricular, periventricular hypothalamic and in the recessus infundibular nuclei. In the mesencephalon, immunoreactive perikarya were seen in the mesencephalic reticular formation, reticular nucleus of the isthmus and torus semicircularis. Labelled fibers ran along the diencephalic floor and the inner zone of the median eminence, and ended in the neural lobe of the hypophysis. Other fibers were observed in the outer zone of the median eminence close to the portal vessels and in the septum, lamina terminalis, retrochiasmatic nucleus, deep layers of the tectum, periventricular gray and granular layer of the cerebellum. Our data suggest that somatostatin may function as a mediator of adenohypophysial secretion as well as neurotransmitter and/or neuromodulator which can regulate the neurohypophysial peptides in the snake B. jararaca.