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

Indirect immunofluorescence histochemistry was used to study the relation among GABAergic, catecholaminergic, cholinergic, and peptidergic neurons in the rat mediobasal hypothalamus. By employing a direct double-labelling procedure using sheep antiserum against glutamic acid decarboxylase (GAD), mouse monoclonal and rabbit antibodies to neurotensin (NT) and rabbit antisera to tyrosine hydroxylase (TH), choline acetyltransferase (ChAT), galanin (GAL), growth hormone-releasing factor (GRF), or somatostatin (SOM), it was demonstrated that GAD-positive fibers and terminals in the external part of the median eminence co-contained immunoreactivity for TH, NT, GAL or GRF, but not for SOM. In the internal part of the median eminence-infundibular stalk, GAD-positive/NT-, GAL-, and GRF-negative and GAD-positive/TH-positive fiber plexa were shown. When a recently developed direct triple-labelling procedure with biotin-conjugated mouse secondary antibodies in conjunction with diethylaminocoumarin (DAMC)-conjugated avidin was employed, presence of GAD/GAL/NT- as well as GAD/GRF/NT-containing varicosities could be demonstrated close to hypophysial portal vessels. In colchicine-pretreated animals, GAD was shown to coexist with TH, NT, or GAL in cell bodies in both the dorsomedial and ventrolateral domains of the arcuate nucleus, but with GRF only in the ventrolateral division. ChAT-positive neurons in the ventrolateral region were also TH-positive. In the ventrolateral arcuate nucleus, triple-labelling followed by elution-restaining showed GAD/NT/GAL/TH-immunoreactivities in the same cells. Similarly, double-labelling with two following elution-restaining steps showed several NT/GAL/GRF/TH-containing cell bodies in this part of the arcuate nucleus. GAD-positive cells in the anterior hypothalamic periventricular area and fibers in the pituitary neurointermediate lobe were also TH-positive. The results demonstrate complex patterns of storage of chemical messengers in neurons of the arcuate nucleus-median eminence complex. Possible neuroendocrine interactions of these systems in the control of prolactin and growth hormone secretion are discussed.
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PMID:Peptide- and transmitter-containing neurons in the mediobasal hypothalamus and their relation to GABAergic systems: possible roles in control of prolactin and growth hormone secretion. 290 36

Somatostatin immunoreactive (SOM-I) perikarya were first observed in the ventral horn at E12, in the presumptive intermediate gray area at E14, and in the alar plate of the rostral spinal cord at E14. In general, after their initial appearance, their density increased and then decreased during development. A moderate density of SOM-I varicosities became obvious in the superficial laminae of the E20 dorsal horn. By E12 a few SOM-I perikarya, interpreted to be dorsal root ganglia, were observed lateral to the spinal cord, and by E13, SOM immunoreactivity was visualized within the central and peripheral processes of dorsal root ganglion axons. In the marginal zone, SOM-I fibers were first demonstrable in the ventral funiculus at E14, and in the lateral funiculus at E15. After their initial appearance, their density increased and then decreased with age, with the exception of the dorsal part of the lateral funiculus where it increased at the early stages of development to an apparently stable level. The early detection of SOM immunoreactivity in specific spinal regions corresponds well with the birth dates of cells in those regions. This indicates that the SOM-I cells are capable of synthesizing the substance at least as early as they have entered their final cell division.
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PMID:Somatostatin immunoreactive structures in the developing rat spinal cord. 290 30

Immunohistochemical and axonal transport methods were used to chart the distribution of somatostatin-immunoreactive (SS-IR) fibres in the paraventricular (PVH) and supraoptic (SO) nuclei of the rat hypothalamus and to identify the cell group(s) from which they originate. Fibres and varicosities immunoreactive for SS-28 and/or SS-281-12 are found primarily in the parvocellular division of the PVH, though aspects of the magnocellular division, and of the SO, in which oxytocinergic neurons are clustered also receive moderate inputs. Combined retrograde transport-immunohistochemical studies indicated that these arise principally from non-catecholaminergic neurons in the lateral aspect of the commissural part of the nucleus of the solitary tract (NTS). SS-28 has been shown to act within the central nervous system to elicit both oxytocin and vasopressin secretory responses, and may be involved in mediating vasopressin secretory responses to haemorrhage. Direct SS-28-IR inputs to the magnocellular cell groups from the NTS, which receives primary visceral sensory inputs, are in a position to play a role in mediating oxytocin secretory responses to interoceptive stimuli; the pathway(s) and mechanism(s) which allow SS-28 to interact with vasopressinergic neurons are not clear.
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PMID:Somatostatin 28-immunoreactive inputs to the paraventricular and supraoptic nuclei: principal origin from non-aminergic neurons in the nucleus of the solitary tract. 290 91

Figure 2 is the algorithm followed in our institution for management of acute variceal hemorrhage. A small percentage of patients who present with active variceal hemorrhage will stop bleeding after gastric lavage alone. However, most patients require an intravenous vasopressin infusion at a dose of 0.4 units per minute, preferably combined with intravenous administration of nitroglycerin. Although glypressin and somatostatin may be associated with fewer side effects than vasopressin, the superiority of these drugs remains to be determined. Whether pharmacologic therapy succeeds or fails, most patients then proceed to endoscopic sclerotherapy. Sclerotherapy may be used as a temporizing measure in preparation for elective surgery or as a long-term, definitive treatment for prevention of recurrent hemorrhage. Balloon tamponade is reserved for patients who are bleeding too rapidly for effective sclerotherapy and for sclerotherapy failures in preparation for emergency surgery. Because recurrent hemorrhage frequently occurs after balloon deflation, a more definitive treatment (surgery or endoscopic sclerotherapy) should be planned for all patients who undergo balloon tamponade. Because operative risk is unacceptably high for patients with hepatic functional decompensation secondary to variceal hemorrhage, we believe that a policy of routine emergency surgery is unwise. Rather, emergency surgical intervention is reserved for the relatively small number of patients (15 to 25 per cent) who continue to bleed after nonoperative options have failed. Shunt surgery should be considered early in the course of patients with bleeding secondary to gastric varices and portal hypertensive gastropathy, both of which respond poorly to nonoperative measures.
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PMID:Variceal hemorrhage. 304 46

The variceal bleeding episode represents several days of high risk of bleeding, thus therapy should be evaluated not only in terms of immediate cessation of bleeding but also in terms of providing a bleed-free interval of a few days. As the risk of continued bleeding or very early rebleeding from varices diminishes rapidly following admission, time is an important confounding variable when comparing therapies within and between trials. Cirrhotics with better liver function are more likely to stop bleeding with simple measures than those with worse liver function. Vasopressin, glypressin, vasopressin combined with nitroglycerin and somatostatin have all been used as splanchnic arteriolar vasoconstrictors thus reducing portal pressure. No trial has demonstrated increased survival with use of these agents. The efficacy of vasopressin is now disputed. Vasopressin combined with nitroglycerin and somatostatin have the fewest side-effects and may be more effective than vasopressin alone. Balloon tamponade arrests bleeding and prevents exsanguination, but should be used solely as a temporizing measure before the use of emergency sclerotherapy or surgery. Sclerotherapy is the only non-operative emergency technique which has been shown not only to stop variceal bleeding, but to reduce the frequency of very early rebleeding. Emergency oesophageal transection is equally if not more effective in arresting bleeding than sclerotherapy and has a lower early rebleeding rate and a similar mortality. Choice of treatment depends on expertise available. Further studies in the management of variceal bleeding should evaluate 3 main areas. Firstly improvement of existing therapies or new therapies. Secondly, investigation of therapies not related to bleeding, eg prophylaxis against infection, improvement in renal support. Lastly evaluation of predictive factors which may a priori determine a high risk of continued bleeding or early rebleeding thus justifying immediate sclerotherapy or surgery in a sub-group of patients.
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PMID:Randomised controlled trials for variceal bleeding. 305 15

The ultrastructure of synapses in the autonomic nervous system is reviewed. The synaptic organization of the parasympathetic ganglia is relatively simple. Preganglionic axons form synapses either on the soma or on short perikaryal processes of the ganglionic neurons. The presynaptic terminals have a cholinergic morphology and contain mainly small clear vesicles with a few large dense cored vesicles. A few neuropeptides have been localized to the large dense cored vesicles of these terminals. The postganglionic parasympathetic axons ramify within their target tissues where they form close associations, but not true synaptic contacts. Sites of release of transmitter are recognized morphologically as varicosities along the length of the axon that contain clusters of small clear vesicles with a few large dense cored vesicles. The organization of the sympathetic nervous system is somewhat more complex. In addition to acetylcholine, enkephalin also exists in these terminals, probably in the large dense cored vesicles. There are at least three types of ganglion cell neurons in the paravertebral portion of the sympathetic nervous system: those that contain norepinephrine alone, those that contain norepinephrine along with neuropeptide Y, and those that contain acetylcholine and vasoactive intestinal polypeptide. The first type provides innervation to the parenchyma of the target tissues, while the second mainly innervates blood vessels. The third type innervates the sweat glands. In the prevertebral ganglia, a fourth type of neuron exists that contains norepinephrine and somatostatin. This neuron probably innervates the gut. Preganglionic terminals of the cholinergic type form synaptic connections mainly with the dendrites of the sympathetic ganglion neurons. In addition to the types of synapses described for the paravertebral ganglia, neurons in the prevertebral ganglia receive synaptic connections from dorsal root ganglia and from the enteric nervous system. The sympathetic ganglia also contain interneurons that receive preganglionic synapses and form efferent synapses with some of the principal ganglion cells. The interneurons have been shown to contain a variety of transmitters, including norepinephrine, epinephrine, dopamine, serotonin, and a number of neuropeptides. The postganglionic sympathetic axons have a similar morphology to the parasympathetic axons. They form networks in their targets, and the axons display varicosities with concentrations of both small and large vesicles. After appropriate fixation, these vesicles are seen to possess dense cores.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Morphology of synapses in the autonomic nervous system. 306 34

The morphological substrate for the central mechanisms that control growth hormone (GH) release in the rat hypothalamus was investigated immunohistochemically by light and electron microscopy. In electron-microscopic studies, a dual immunolabeling technique was employed to demonstrate pairs of peptides, i.e. rat hypothalamic growth hormone-releasing factor (rhGRF) and somatostatin (SRIH), rhGRF and substance P (SP), and rhGRF and methionine-enkephalin-Arg6-Gly7-Leu8 (Enk-8), in different neuronal structures. Immunoreactivity of rhGRF was detected as silver-gold particles and those of the other substances as diaminobenzidine products by preembedding immunostaining procedures. In the external layer of the median eminence, axonal terminals immunolabeled for rhGRF and for SRIH showed the same pattern of distribution and close proximity. The neuronal inputs to GRF cell bodies in the arcuate nucleus were examined, and SRIH, SP and Enk-8 fibers with varicosities were found to form dense networks around the perikarya of GRF neurons, suggesting the presence of synaptic associations. Axonal terminals immunolabeled for SRIH, SP or Enk-8, and unlabeled terminals appeared to form coincidental synaptic junctions on GRF perikarya. These findings suggest that the central regulation of GH release occurs at the levels of the median eminence and the cell bodies.
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PMID:Ultrastructural evidence for neuronal regulation of growth hormone secretion. 313 6

The distribution of substance P-like immunoreactivity within the squid retina and brain was studied by immunofluorescence. Positive immunoreactivity was observed as a single layer of fibres in the retina. The retina was devoid of tyrosine-hydroxylase, serotonin, gamma-aminobutyric acid, cholecystokinin, neuropeptide Y, somatostatin, enkephalin and vasoactive intestinal peptide immunoreactivities. Substance P immunoreactivity was particularly abundant in the optic lobe. The optic lobe had a distinct layer of substance P fibres near the periphery. Immunoreactive cell bodies, fibres and varicosities were additionally present in various areas of the optic lobe. Substance P immunoreactivity in the other ganglia of the brain was restricted to a few scattered fibres.
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PMID:Substance P-like immunoreactivity in the retina and optic lobe of the squid. 353 37

Somatostatin-like immunoreactivity (SLIR) has been assayed in frontal and temporal cortex obtained at diagnostic craniotomy and post-mortem from patients with histologically verified Alzheimer's disease. SLIR content was not significantly different from controls in the frontal and temporal lobes, except in the temporal cortex post-mortem. The K+-stimulated release of endogenous SLIR from tissue prisms ('mini-slices') prepared from neocortex obtained at diagnostic craniotomy from Alzheimer patients was not below the control values. Indices of cholinergic varicosities in similar samples from the frontal and temporal lobes are reduced; accordingly, somatostatin does not seem to be as prominently involved in these regions. Patients with Alzheimer's disease underwent neuropsychological assessment shortly before sampling the temporal lobe. Scores for WAIS full scale and the verbal subscale and the Token Test (measure of language comprehension) significantly correlated with the SLIR content; mean values (fmole/mg protein) were 817, 1468 and 1363 for aphasic and non-aphasic Alzheimer patients and controls, respectively. Ventricular fluid obtained from Alzheimer patients during surgery, did not have a significantly different SLIR content compared to controls. SLIR contents of ventricular fluid and neocortex from demented patients, without any specific histological changes in the sample obtained at diagnostic craniotomy, were also not significantly different from controls. Previously, we have shown that these demented patients, as well as those with histologically verified Alzheimer's disease, have a reduced SLIR content of lumbar fluid so it seems that somatostatin neurones located outside the frontal and temporal lobes are affected relatively early in the disease process.
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PMID:Somatostatin content and release measured in cerebral biopsies from demented patients. 357 46

Examination of the cortex and the subcortical white matter by use of an immunocytochemical technique--the per oxidase anti-per oxidase method--shows that somatostatin is located in a widespread neuron system with cell bodies localized in both the cortex and the subcortical white matter of the human brain. In the cortex, the somatostatin cell bodies and fibers are found in all layers, but the fibers are especially numerous in layer I located tangentially to the brain surface. The fibers are very long and subdivide into many branches which form a network of pathways in the deeper cortical layers. There are numerous varicosities along the fibers and they come into close contact with other non-immunoreactive neuronal cells. The somatostatin cells located in the white matter are larger than the somatostatin cells in gray matter. They are giant cells with a size ranging from 50 to 120 micrometers. The fibers from these cells are varicose and can be followed both rostrally into the cortical gray matter and caudally in the subcortical white matter. The localization and the morphology of the somatostatin neurons in the cortex and the subcortical white matter indicate that somatostatin may be able to exert sustained influence in various brain areas and thereby modulate integrative and/or specific functions, not only via connection in the gray matter but also by influencing the neuronal circuits passing through the subcortical white matter.
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PMID:Somatostatin: localization and distribution in the cortex and the subcortical white matter of human brain. 612 14


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