Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In previous immunohistochemical studies in the rat and monkey, a system of somatostatin-positive neurons and fibers was observed in the dentate gyrus of the hippocampal formation. In both species, somatostatin-immunoreactive cell bodies are located primarily in the deep or polymorphic layer of the dentate gyrus, and they give rise to a fiber system that terminates principally in the outer two-thirds of the molecular layer. In the present study, we employed the same antisera and staining procedures to determine whether the organization of the somatostatin system in the human dentate gyrus is similar to that seen in the rat and nonhuman primate. Sections of human postmortem brain material incubated with antisera directed against somatostatin 28 (S320) or somatostatin 28 (S309) demonstrated a heterogeneous population of immunoreactive cells in the hilar region of the human dentate gyrus. Fiber staining was observed both in the hilar region and throughout the molecular layer, but the densest fiber and terminal plexus were observed in the outer two-thirds of the molecular layer. In addition, there were forms of somatostatin-immunoreactive profiles in the human sections that were not previously observed in the rat or monkey. Immunoreactive, grapelike clusters of apparently large, axonal varicosities were commonly observed, for example, as were dendritic profiles containing typical dendritic spines. In general, however, staining for somatostatin immunoreactivity in the human dentate gyrus presented a picture qualitatively similar to that observed in the rat and monkey. Thus, immunohistochemical methods have allowed the analysis of a chemically defined neural system in the human brain that has been extensively studied in rat and monkey brains with both experimental and immunohistochemical methods. That the pattern of labeling in the human sections closely parallels that observed in the experimental animals provides support for the contention that immunohistochemical methods can reliably be employed to determine the normal neuroanatomical organization of the human brain. These methods may also be particularly applicable for the analysis of pathological brain conditions. In particular, alterations of the hippocampal somatostatin system have been associated with both Alzheimer's disease and temporal lobe epilepsy. It would be of interest, therefore, to apply immunohistochemical procedures to determine whether the anatomical organization of the human hippocampal somatostatin system is altered in these diseases.
 ...
PMID:Distribution of somatostatin immunoreactivity in the human dentate gyrus. 245 24

The distribution of somatostatin-like immunoreactivity was studied in the macaque monkey (Macaca fascicularis) by using primary antisera that recognize somatostatin-28 (S309) or somatostatin-28(1-12) (S320). Somatostatin-immunoreactive neuronal cell bodies were observed in all amygdaloid nuclei and cortical regions. The density of labeled cells varied substantially, however, both within and across the various amygdaloid subdivisions. The highest densities of labeled neurons were observed in layer III of the periamygdaloid cortex, in layers II and III of the medial nucleus, in the magnocellular division of the accessory basal nucleus, and in the medial portion of the lateral nucleus. Many labeled cells were also consistently observed in the caudoventral portion of the lateral division of the central nucleus. Labeled cells were heterogeneous in size and shape ranging from small and spherical to large and multipolar. The density of somatostatin-immunoreactive fibers also varied greatly from region to region and was often inversely related to the density of immunoreactive cells. Highest densities of immunoreactive fibers were observed in the periamygdaloid cortex, medial nucleus, parvicellular division of the accessory basal nucleus, paralaminar nucleus, ventrolateral portion of the lateral nucleus, parvicellular division of the basal nucleus, and the lateral division of the central nucleus. Fibers and terminals in the central nucleus had a coarsely varicose appearance and this pattern of staining was continuous along the trajectory of the central nucleus projection to the bed nucleus of the stria terminalis. The large, immunoreactive varicosities located in this area often appeared to outline dendritic or vascular profiles within the substantia innominata. The lowest levels of somatostatin-immunoreactive fibers were observed in the magnocellular division of the basal nucleus and in the ventromedial portion of the accessory basal nucleus.
 ...
PMID:Distribution of somatostatin-like immunoreactivity in the monkey amygdala. 256 98

Retrograde-tracing and immunohistochemical techniques were used in combination to investigate the types of putative transmitters in pelvic neurons that project to the bladder, colon or penis of rats. In addition, populations of axon varicosities associated with these neurons were characterized. Subpopulations of neurons in colchicine-treated major pelvic ganglia and accessory ganglia of male rats contained immunoreactivity (IR) for tyrosine hydroxylase (TH), vasoactive intestinal peptide (VIP), neuropeptide Y (NPY), or enkephalin (ENK), while types of immunoreactivity found in major groups of varicose axons were ENK, cholecystokinin (CCK), and somatostatin (SOM). Substance P (SP)-IR varicose axons were much less common. Bladder and colon neurons were similar in a number of ways. Many neurons contained NPY-IR (greater than or equal to 50%), fewer contained TH-IR (25-30%), and even fewer contained ENK-IR (5-15%) or VIP-IR (5-10%); many neurons were associated with baskets of ENK-IR varicosities (50-65%) and fewer neurons were surrounded by CCK- or SOM-IR varicosities (30-35%). Colon neurons differed from penis neurons in having a slightly larger proportion that contained ENK-IR (10-15%, compared with 1-3%). Penis neurons were markedly different from the other two groups in additional ways. More than 90% of them contained VIP-IR, whereas only 5-7% contained NPY-IR and none were immunoreactive for TH. Furthermore, although the proportion of penile neurons associated with many ENK-IR varicosities was similar to the bladder and colon neurons (45-50%), they were rarely seen close to CCK- or SOM-IR varicose axons. These studies describe similarities and differences in the histochemical properties of neurons which project to the bladder, colon, or penis and of the varicose axons associated with those neurons. This gives further insights into the possible transmitter mechanisms involved in the regulation of different pelvic functions.
 ...
PMID:Immunohistochemical characterization of pelvic neurons which project to the bladder, colon, or penis in rats. 257 23

Direct synapses from 5-hydroxytryptamine-, neuropeptide Y-, and somatostatin-immunoreactive axon varicosities to the preganglionic sympathetic neurons retrogradely labeled with horseradish peroxidase were observed in the thoracic intermediolateral nucleus of the guinea pig. Symmetric synapses were predominant and both axo-dendritic and axo-somatic contacts were observed.
 ...
PMID:Direct synaptic contacts of 5-hydroxytryptamine-, neuropeptide Y-, and somatostatin-immunoreactive nerve terminals on the preganglionic sympathetic neurons of the guinea pig. 257 27

Electron microscopic immunocytochemistry was used to identify somatostatin-immunoreactive nerve profiles around the capillary system of the small intestine in the rat and cat. The highest density of somatostatin-immunoreactive nerve profiles was seen in the mucosa, and 25-30% of all immunoreactive profiles were found immediately adjacent to the endothelial cells of capillary blood vessels. About half of the capillary endothelial cells were fenestrated. The majority of the immunoreactive nerve profiles were varicosities, containing synaptic vesicles. These observations suggest that somatostatin might be released from varicose nerve fibers and may contribute to the elevated levels of the peptide measured in portal blood as compared to peripheral blood.
 ...
PMID:Somatostatin-immunoreactive nerve fibers in close association with capillaries in the small intestine. 257 49

While several peptides have been shown to coexist in perikarya within dorsal root ganglia of rat, coexistence of peptides has not been confirmed in axons associated with these neurons. In this study, the coexistence of substance P (SP) with somatostatin (SOM), calcitonin gene-related peptide (CGRP), dynorphin A 1-8 (DYN), neurotensin (NT), galanin (GAL), and 5-HT in varicosities was visualized using fluorescence immunohistochemistry. Densities of immunoreactive varicosities within laminae I and II of the dorsal horn of the rat spinal cord were quantified by computer-assisted image analysis. Decreases in densities of immunoreactive varicosities as a result of multiple unilateral dorsal rhizotomies were used to determine proportions of immunoreactive varicosities associated with primary afferent neurons. Three observations were made. (1) Dorsal rhizotomy depleted greater than one-third of the varicosities individually immunoreactive for SP, SOM, GAL, or DYN, confirming the association of these peptides with primary afferent neurons. (2) SP coexisted with CGRP, GAL, and DYN in varicosities within the dorsal horn of normal animals. (3) CGRP-, SP+CGRP-, and SP+GAL-immunoreactive varicosities were nearly depleted following dorsal rhizotomy. The depletion of these peptides, particularly in combination, indicates that they may be used as markers for varicosities of some primary afferent neurons within the superficial laminae of the dorsal horn of the rat spinal cord.
 ...
PMID:A quantitative study of the coexistence of peptides in varicosities within the superficial laminae of the dorsal horn of the rat spinal cord. 264 83

The pathophysiology and treatment of esophageal varices are reviewed. The cause of esophageal varices is generally thought to be portal hypertension. The most common cause of portal hypertension in the United States is alcoholic liver disease. Other etiologies of portal hypertension include portal vein thrombosis, schistosomiasis, and inferior vena caval obstruction by tumor or thrombus. Although short-term balloon tamponade and vasopressin infusion will control acute variceal hemorrhage, they do not affect the underlying problem and are not indicated for long-term treatment of esophageal varices. Surgical procedures either ablate varices or lower portal vein pressure. Portal-systemic shunts have emerged as the preferred surgical technique, but the superiority of total versus selective shunts is unclear. Pharmacological management can include administration of vasopressin, somatostatin, verapamil, or isosorbide dinitrate for short-term treatment or verapamil, isosorbide dinitrate, or propranolol for prolonged treatment. Use of sclerotherapy for treatment and prevention of hemorrhage from esophageal varices has grown recently. Because there are several sclerosing agents and combinations of agents available for use, assessing their relative safety and efficacy is difficult. Innovative approaches to management of varices include a shunt procedure involving the left lung, use of a tissue adhesive, and laser treatment. Because of its effectiveness and ease of administration, sclerotherapy appears to be a rational method of treatment for acute hemorrhage from esophageal varices.
 ...
PMID:Treatment of esophageal varices. 264 81

Portal hypertension is a frequent syndrome characterized by a chronic increase in portal venous pressure and by the formation of portal-systemic collaterals. Its main consequence is massive bleeding from ruptured esophageal and gastric varices. Bleeding is promoted by increased portal and variceal pressure, and is favored by dilatation of the varices. The evaluation of the portal hypertensive patient should include the assessment of portal vein patency by ultrasonography, endoscopic evaluation of the presence, size, and extent of esophageal varices, and hemodynamic studies with measurements of portal pressure and of portal-collateral blood flow. The preferred techniques are hepatic vein catheterization and measurement of azygos blood flow. Endoscopic measurements of variceal pressure and estimations of portal blood velocity by the Doppler technique have recently been introduced, but are still research procedures. Acute variceal hemorrhage should be treated under intensive care. Specific therapy to arrest variceal bleeding includes balloon tamponade, vasopressin, somatostatin, sclerotherapy, and emergency surgery. Treatment of portal hypertension is aimed at preventing variceal hemorrhage and bleeding-related deaths. Pharmacologic prophylaxis is based on the use of drugs that cause a sustained reduction in portal pressure; most studies have used propranolol. Surgery and endoscopic sclerotherapy can also be used to prevent rebleeding.
 ...
PMID:Portal hypertension. 265 68

The most common complication of chronic pancreatitis is pain, which in many cases seems related to pancreatic ductal obstruction with ductal hypertension. Longitudinal pancreaticojejunostomy is indicated in patients with a dilated (larger than 7 mm) duct and pain that requires narcotic analgesics for relief. Chronic pseudocysts may be corrected surgically without the usual 6-week wait, and asymptomatic pseudocysts less than 4 cm in diameter may not require surgery at all. The relative efficacy and risks of percutaneous drainage of pseudocysts versus the standard surgical approaches need to be studied. Pancreatic fistulas may be external or internal, where pancreatic ascites or hydrothorax can be the clinical manifestation. The pharmacologic suppression of pancreatic secretion (e.g., with somatostatin) may be useful in their management, but surgery may be required. Pancreatic resection or internal drainage is usually effective. Persistent jaundice should be relieved surgically by choledochoduodenostomy to avoid the development of secondary biliary cirrhosis. Obstruction at various levels of the gastrointestinal tract (duodenum, small bowel, colon) may require bypass (gastrojejunostomy) or resection. Hemorrhage from major arteries is an infrequent but often lethal complication of chronic pancreatitis, especially associated with pseudocysts. Angiography is invaluable for diagnosis and occasionally for treatment (embolization). Surgery is preferred in good-risk patients, with suture ligation (resection) of the bleeding source. Chronic pancreatitis is the most common cause of splenic vein thrombosis. The resultant hemorrhage from gastric varices is managed effectively by splenectomy.
 ...
PMID:Complications of chronic pancreatitis. 265 60

Nerve terminals of the rat median eminence, arcuate nucleus and spinal cord were examined in the electron microscope after post-embedding, colloidal gold labelling of immunoreactivity to somatostatin. Strong immunostaining was thus obtained together with adequate morphological preservation. Reactive boutons showed clusters of gold particles essentially confined to dense-cored vesicles. In the median eminence, the positive varicosities made up more than half of all terminals and averaged 735 nm in diameter. Those in the arcuate nucleus and spinal cord were much less numerous and generally smaller (575 nm). The labelled vesicles had mean external diameters of 109, 95 and 79 nm in the median eminence, arcuate nucleus and spinal cord, respectively. Calculations of the likely amounts of somatostatin within the vesicles of the median eminence and arcuate nucleus yielded values of 0.7 and 1.4 mM, corresponding to 190 and 230 molecules of the peptide, respectively. These data support a neurotransmitter or modulator role for somatostatin in the central nervous system.
 ...
PMID:Ultrastructural morphometric analysis of somatostatin-like immunoreactive neurones in the rat central nervous system after labelling with colloidal gold. 286 2


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>