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)

A motor disorder similar to idiopathic Parkinson's Disease develops in rhesus monkeys after several daily repeated doses of N-methyl-4-phenyl, 1,2,3,6-tetrahydropyridine (MPTP). The concentrations of peptides derived from proenkephalin A, proenkephalin B, substance P and somatostatin were measured by specific radioimmunoassays in the basal ganglia of MPTP-treated monkeys. In MPTP-treated monkeys, dynorphin B concentration was reduced in the caudate. In the putamen, the concentrations of peptides derived from both proenkephalin A and proenkephalin B were decreased. In the globus pallidus, the concentrations of all opioid peptides tend to be increased, reaching significance only for alpha-neo-endorphin. In the substantia nigra, only Met-enkephalin concentration was reduced, while other peptides derived from either proenkephalin A or proenkephalin B were not changed. Substance P and somatostatin were not changed in any brain area examined. Some of the symptoms associated with Parkinson's Disease may be related to altered activity of endogenous opiates in basal ganglia.
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PMID:Primate model of Parkinson's disease: alterations in multiple opioid systems in the basal ganglia. 615 Jul 50

The distribution of substance P-, Met-enkephalin- and somatostatin-like immunoreactivity was studied in the thoracic spinal cord of the frog using immunohistochemical techniques. In fibres, probably nerve terminals, immunoreactivity was greatest in the grey matter (mainly dorsal horn), but it was also present in white matter regions. While substance P- and, perhaps, somatostatin-like immunoreactivity appeared to be contained in primary afferents, the presence of all 3 peptides in neuronal cells of the grey matter indicates the existence of a propriospinal peptidergic system.
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PMID:Substance P-, met-enkephalin- and somatostatin-like immunoreactivity distribution in the frog spinal cord. 617 Sep 16

Somatostatin distribution was measured quantitatively in the rat spinal cord by radioimmunoassay. Rostro-caudally, somatostatin content was about 50% higher in lumbar-sacral cord than in cervical or thoracic levels. The dorso-ventral distribution is more uneven: somatostatin is highest in the dorsal horn, where the peptide is 15 times as concentrated as it is in the ventral white matter, the region of lowest concentration. However, measurable amounts of the peptide were found in all regions studied. Dorsal root ganglionectomy decreased somatostatin levels in the dorsal cord, supporting the previously proposed role for this peptide as a primary sensory neurotransmitter or modulator; but somatostatin content also was decreased both rostral and caudal to spinal transection, indicating the presence of ascending and descending somatostatin pathways within the spinal cord. Brain levels did not change. Met-enkephalin and substance P were also measured after the above surgical manipulations. Met-enkephalin content was not altered and substance P content was lowered significantly only after ganglionectomy. Although this study confirms the primary sensory neuron as the origin of a part of spinal cord somatostatin, it further indicates the presence of ascending and descending somatostatin pathways within the rat spinal cord.
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PMID:Evidence for ascending and descending intraspinal as well as primary sensory somatostatin projections in the rat spinal cord. 617 91

The preganglionic sympathetic neurons in the intermediolateral cell column of the thoracic and upper lumbar segments of the spinal cord which innervate the chromaffin cells in the adrenal medulla, sympathoadrenal preganglionic neurons, were identified by the method of retrograde axonal transport of the fluorescent dyes Fast Blue and True Blue. In rats, Fast Blue or True Blue was injected into the medulla of the left adrenal gland. After a survival period of 5 days, the animals were perfusion fixed, the thoracic and lumbar spinal cord sectioned and processed for the immunofluorescent localization of met-enkephalin, neurophysin, oxytocin, serotonin, somatostatin and substance P immunoreactivity. Neuronal perikarya which were retrogradedly-labeled with Fast Blue or True Blue were observed in the intermediolateral cell column from the T1 to the L2 spinal cord segments. The distribution of the sympathoadrenal neurons was determined by counting the number of retrogradedly-labeled neurons per spinal cord segment. In the five animals used for quantifying the sympathoadrenal preganglionic neurons, the majority (72.3%) of the retrogradely-labeled neurons counted per spinal cord were located within the T7-T12 segments. The T9 segment contained the largest average number (20.1%) of retrogradely-labeled cells in a single segment. Met-enkephalin, serotonin and substance P immunoreactive fibers were prominent in the intermediolateral cell column, whereas oxytocin, neurophysin and somatostatin immunoreactive fibers were sparse. The met-enkephalin, serotonin and substance P fibers were seen surrounding both unlabeled and retrogradely-labeled neurons; somatostatin fibers appeared to preferentially contact retrogradely-labeled neurons; whereas, the neurophysin and oxytocin fibers were not found in proximity to retrogradely-labeled neurons. Met-enkephalin, neurophysin, oxytocin, somatostatin and substance P immunoreactivity were depleted in the intermediolateral cell column below the level of a spinal cord transection. Serotonin immunoreactivity was depleted in the intermediolateral cell column below the level of the transection for five to six segments, but sparse networks of immunoreactive fibers were observed in both the intermediolateral cell column and the ventral horn in more caudal segments. Met-enkephalin, serotonin, somatostatin and substance P immunoreactivity were decreased in both the contralateral and ipsilateral intermediolateral cell column below the level of a spinal cord hemisection, suggesting that both crossed and uncrossed descending pathways exist. Neurophysin and oxytocin immunoreactivity were depleted below the level of the hemisection in the ipsilateral intermediolateral cell column without noticeable decrease in the level of immunoreactivity in the contralateral intermediolateral cell column, suggesting that a decussation does not occur at the level of the spinal cord, but may exist above the level of the hemisection...
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PMID:The differential distribution and relationship of serotoninergic and peptidergic fibers to sympathoadrenal neurons in the intermediolateral cell column of the rat: a combined retrograde axonal transport and immunofluorescence study. 618 Mar 52

We have prepared a fluorescent conjugate of porcine calmodulin with 5-(dimethylamino)-1-naphthalene-sulfonyl chloride that is highly sensitive to both calcium binding and protein binding. We have used the fluorescence of this conjugate in addition to the intrinsic peptide fluorescence to show that adrenocorticotropic hormone (ACTH), beta-endorphin, glucagon, and substance P undergo calcium-dependent binding by calmodulin, with competition for common binding sites. The dissociation constants determined in the presence of 0.85 mM CaCl2 and 0.2 N KC1, pH 7.3 at 25 degrees C, range from 1.5 muM to 3.4 muM. The alpha-melanocyte-stimulating hormone, bombesin, and somatostatin also bind, with dissociation constants between 60 muM and 90 muM. Angiotensins I and III, bradykinin, neurotensin, physalaemin, substance P octapeptide, insulin, and Leu- and Met-enkephalin show little or no binding. Sequence comparisons show that the peptides that bind calmodulin well contain regions structurally similar to the recognition sequence for the cAMP-dependent protein kinase and to the sequences surrounding phosphorylated serine residues in several calmodulin binding proteins. This result suggests that modification of calmodulin binding sites in calmodulin-dependent proteins is one of the functions of protein kinase. Calcium has a dual role in peptide binding by calmodulin. The occupation of calcium binding sites having a pK approximately 4 results in a 2-fold increase in peptide binding affinity.
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PMID:Binding of simple peptides, hormones, and neurotransmitters by calmodulin. 618 Jul 61

Studies were performed to investigate the effects of neurotransmitters and neurotransmitter candidates (substance P, VIP, somatostatin, Met-enkephalin, gastrin-17, CCK-4 and -8, neurotensin and TRH) of the newly discovered peptidergic nervous system on lower oesophageal sphincter pressure in anaesthetized pigs. All neuropeptides were infused over 2 min periods in 6 different doses, separated by resting periods of at least 1 min, directly into the arterial supply of the lower oesophageal sphincter. Substance P caused a dose-dependent increase in lower oesophageal shpincter pressure; the threshold dose was 9 pmol . kg-1 . min-1 and half maximal response occurred at 72 pmol . kg-1 . min-1. None of the other polypeptides, however, influenced the resting lower oesophageal sphincter. These studies show that substance P is a potent stimulant of smooth muscle in the lower oesophageal sphincter, suggesting that this peptide may be an important regulator of lower oesophageal sphincter pressure.
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PMID:Effects of regulatory peptides on the porcine lower oesophageal sphincter. 618 84

An account is given of the authors' work with isolated adrenal chromaffin cells to study the synthesis, storage and release of catecholamines and of a number of neuropeptides endogenous to the adrenal medulla. A review of other studies in the literature with the isolated chromaffin cell system is included. It is seen that the isolated chromaffin cells are a convenient in vitro system well-suited to studies of basic release mechanisms. The isolated adrenal chromaffin cells maintain high levels of catecholamines and opiates and release them by exocytosis. The cells have both nicotinic and muscarinic receptors but only the nicotinic are involved in the agonist-evoked release of catecholamines (EC50 nicotine 5 X 10(-6) M: ACh 5 X 10(-5) M). The cells can synthesize AChE and selectively release the 10S molecular form by a mechanism different from exocytosis. Substance P (SP) modulates the secretion of catecholamines and ATP evoked by ACh or nicotine but not that evoked by K+ or veratridine. SP appears to interact with the nicotinic receptor-ionophore complex to regulate Na+ entry. SP receptors on the chromaffin cells show similar structural requirements to SP receptors in other SP responsive tissues. Binding studies on isolated chromaffin cell membranes with [4-3H-Phe]SP have shown specific binding in the nM range. In addition, at high concentrations of ACh, SP protects against nicotinic receptor desensitization. Since SP is contained in the splanchnic nerve terminals that innervate the medulla, the demonstration of SP action and SP receptors on the chromaffin cells suggests a physiological role for SP in the regulation of secretion from the adrenal medulla. Somatostatin (SS) and a number of SS analogues also inhibit release, but are approximately 15-fold less potent than SP. Leu- and Met-enkephalin, which are co-stored with adrenaline in the bovine adrenal medullary cells produce a non-specific inhibition of the nicotine-evoked release of CA, but enhance the basal release of endogenous catecholamines by a mechanism that is Ca2+-dependent, stereospecific and reversible by naloxone and naltrexone. The implication of these peptide-amine interactions for physiological processes regulating homeostasis in the adrenal are discussed.
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PMID:Use of isolated chromaffin cells to study basic release mechanisms. 618 74

The effects of intraocular injection of kainic acid and acrylamide upon retinal neuropeptides and high affinity binding sites have been determined in the chick. Kainic acid causes a sharp reduction in Met-enkephalin and somatostatin while neurotensin levels are unchanged. This treatment also lowers the extent of cholinergic muscarinic but not of [3H]naloxone or [3H]spiroperidol binding. In contrast, acrylamide treatment causes major increases of retinal Met-enkephalin and neurotensin concentrations. The binding of [3H]naloxone is also increased, and no reductions of any peptide or binding intensity were observed. The results indicate the plasticity of retinal neuropeptide levels and the selectivity with which these can be modulated.
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PMID:Alterations in retinal neurotransmitter receptors and neuropeptides of the chick by kainic acid and acrylamide. 619 41

The ultrastructural localization of four neuropeptides, substance P, vasoactive intestinal polypeptide, Met-enkephalin, and somatostatin, in the guinea pig colon was investigated using electron immunocytochemistry. Each peptide was localized to the large granular vesicles in separate subpopulations of p-type nerves. These nerves could often be distinguished by the size and appearance of their immunostained granular vesicle cores. Thus, vasoactive intestinal polypeptide- and somatostatin-immunoreactive vesicles contained cores that were significantly larger (p less than 0.005) than those of substance P- or Met-enkephalin-positive vesicles. In addition, vasoactive intestinal polypeptide-immunoreactive vesicle cores were less well defined and more variable in shape than those of somatostatin-positive vesicles. Substance P- and Met-enkephalin-immunoreactive vesicle cores, however, were very similar in size (p greater than 0.05) and appearance and could only be differentiated using immunocytochemistry. This study demonstrates that the four neuropeptides under investigation are present within separate, often ultrastructurally distinct, neuronal systems in the gut. The distribution of these nerves within the colon is also described.
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PMID:Ultrastructural localization of four different neuropeptides within separate populations of p-type nerves in the guinea pig colon. 619 38

The presence of peptides in pure cultures of neurons from 8-day-old chick embryo cerebral hemispheres has been investigated by means of specific radioimmunoassays and chromatographic purification. Somatostatin, Met-enkephalin, Leu-enkephalin, and substance P immunoreactive substances have been detected in 8-day-old cultures grown in serum-free culture medium. The peptides were present in the cellular extracts, as well as in the culture medium extracts. beta-Endorphin, thyroliberin, luteinizing hormone-releasing hormone, and ACTH could not be detected. The largest amount was accounted by somatostatin (48 +/- 2 ng/mg protein). Some 60% of the somatostatin-immunoreactive material was found in the culture medium. Met-enkephalin, Leu-enkephalin, and substance P were present at lower concentrations: 1.61 +/- 0.27, 0.24 +/- 0.02, and 0.14 +/- 0.005 ng/mg protein, respectively. The identities of somatostatin- and enkephalin-immunoreactive materials were confirmed by high pressure liquid chromatography. The findings suggest that cultured neurons that express dopaminergic and GABAergic properties contain peptides similar, if not identical, to somatostatin, Met-enkephalin, Leu-enkephalin, and substance P.
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PMID:Presence of somatostatin, enkephalins, and substance P-like peptides in cultured neurons from embryonic chick cerebral hemispheres. 619 58


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