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)

Biologically active peptides and neurotransmitter substances were added to anterior pituitary cell cultures to examine the presence of corticotropin releasing factor (CRF)-like activity. Hypothalamic extract (HE) induced significant dose-related increase of ACTH, and the lowest effective dose was 0.01 HE/ml. Other tested substances including luteinizing hormone-releasing hormone, thyrotropin releasing hormone, melanocyte stimulating hormone release inhibiting factor, somatostatin, substance P, neurotensin, beta-endorphin. leu-enkephalin, met-enkephalin, bradykinin, norepinephrine, dopamine, serotonin, acetylcholine, histamine, gamma-amino butyric acid or gamma-hydroxy butyric acid showed no CRF-like activity. Relatively high doses of lysine vasopressin, arginine vasopressin and angiotensin II increased the release of ACTH in pituitary cell cultures, but the maximal ACTH response was markedly less than with HE. These results indicate that cultured anterior pituitary cells are sensitive and fairly specific in detecting CRF(s) comparing with other detecting procedures.
 ...
PMID:Specificity of cultured anterior pituitary cells in detecting corticotropin releasing factor(s): the effect of biologically active peptides and neurotransmitter substances on ACTH release in pituitary cell cultures. 3 34

Several neurotransmitters have been reported to exist in the ganglionated plexus of the guinea pig gallbladder. These include substance P, neuropeptide Y (NPY), calcitonin gene-related peptide, vasoactive intestinal peptide (VIP), acetylcholine, norepinephrine, serotonin, and dopamine. To determine which neuropeptides are intrinsic to gallbladder ganglia, we performed immunohistochemistry on colchicine-treated preparations. In separate, single-labeled preparations, a majority of neurons contained substance P-, NPY-, or somatostatin-like immunoreactivity. In double-labeled preparations, a large majority of the neurons that contained substance P-like immunoreactivity also contained NPY-like immunoreactivity and somatostatin-like immunoreactivity. Immunoreactivity for VIP was present in a small percentage of the gallbladder neurons which did not contain substance P-like immunoreactivity. Additional experiments were done to test for the presence of other compounds, known to exist in the neurons of the gut. Although immunoreactivity was found in control preparations of small intestine, the ganglionated plexus of the gallbladder lacked immunoreactivity for galanin, dynorphin, enkephalin, gastrin-releasing peptide, or gamma-aminobutyric acid. We conclude that ganglia of the guinea pig gallbladder contain at least two populations of neurons, based on transmitter phenotype. One of these populations appears to contain substance P, NPY, and somatostatin. Another population, which represents a small contingent of the total population of neurons, contains VIP.
 ...
PMID:Transmitter diversity in ganglion cells of the guinea pig gallbladder: an immunohistochemical study. 134 12

Superior cervical ganglia from 7 human cadavers (3-7 h post mortem) were immunostained for tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (DBH) and 14 different neuropeptides. The results show that ganglionic cells contain TH, DBH, neuropeptide Y (NPY), somatostatin, vasoactive intestinal polypeptide (VIP) and calcitonin gene-related peptide (CGRP). These substances were present predominantly within large ganglionic cells. Inside the ganglion, the number and topographical distribution of various types of immunoreactive cells differed from one another. NPY and CGRP immunoreactivities were found in some TH-positive cells, but that co-localization never exceeded the 30% of the TH cells. Leu-enkephalin showed a weak immunoreactivity, which was restricted to fibers or varicosities. Neuropeptides like substance P, dynorphin A and B, cholecystokinin, galanin, corticotropin-releasing factor, thyrotropin-releasing hormone, angiotensin II and neurotensin showed no immunoreactivity in the human superior cervical ganglion.
 ...
PMID:Neuropeptides in the human superior cervical ganglion. 135 73

The main somatostatin-degrading proteases were purified from rat and pig brain homogenates and characterized as thiol- and metal-dependent endoproteases. Two types of proteases with apparent native and subunit molecular masses of 70 kDa and 68 kDa could be differentiated in both species. Beside somatostatin, both hydrolyzed several other neuropeptides with chain lengths between 8 and 30 amino acid residues. Cleavage sites were generally similar or identical, but some clear exceptions were observed for enzymes from both species which could be used to differentiate between the two proteases. The 68-kDa protease cleaved somatostatin at three bonds (Asn5-Phe6, Phe6-Phe7 and Thr10-Phe11) and neurotensin only at the Arg8-Arg9 bond, whereas the 70-kDa protease digested somatostatin at only two bonds (Phe6-Phe7 and Thr10-Phe11) and neurotensin as well as acetylneurotensin-(8-13) additionally (pig protease) or almost exclusively (rat protease) at the Pro10-Tyr11 bond. Relative rates for the digestions of various peptides were, however, more dependent on the species than on the type of protease. Cleavage sites for angiotensin II, bradykinin, dynorphin, gonadoliberin and substance P were, apart from different rates, identical for both proteases. In both species the 68-kDa protease was found to be mainly, but not exclusively, soluble and not membrane-associated, whereas the inverse was detected for the 70-kDa protease. Based on distinct molecular and catalytic properties, the 68-kDa protease is supposed to be congruent with the endopeptidase 24.15 (EC 3.4.24.15), the 70-kDa protease with endopeptidase 24.16 (EC 3.4.24.16, neurotensin-degrading endopeptidase). This investigation demonstrates that both proteases hydrolyze various neuropeptides with similar cleavage sites, but with species-dependent activity. Species-independent distinctions are the exclusive action of endopeptidase 24.16 on acetylneurotensin-(8-13) and liberation of free Phe from somatostatin only by endopeptidase 24.15.
 ...
PMID:Purification of the main somatostatin-degrading proteases from rat and pig brains, their action on other neuropeptides, and their identification as endopeptidases 24.15 and 24.16. 135 47

Dopaminergic modulation of neuropeptides in rat striatum was investigated by examining the effects of prolonged D1 or D2 receptor stimulation on levels of somatostatin, neuropeptide Y, neurotensin, dynorphin and enkephalin. Rats with a unilateral 6-hydroxydopamine (6-OHDA) lesion of the nigrostriatal pathway were treated for 7 days with either the D1 agonist SKF 38393 (12.5 mg/kg/day) or the D2 agonist quinpirole (1 mg/kg/day). Two regimens of agonist treatment were compared: continuous infusion via osmotic pump implanted i.p. and intermittent (once daily) i.p. injection. Rats were sacrificed 3 h after the last injection and peptide levels measured in the striatum bilaterally by radioimmunoassay; alterations in peptide content were observed primarily in the denervated striatum. In comparison to values from lesioned, vehicle-treated controls, intermittent administration of SKF 38393 reduced somatostatin and neuropeptide Y (down 61% and 57%, respectively), increased neurotensin (up 105%) and dynorphin (up 184%) and had no effect on enkephalin; continuous SKF 38393 decreased neuropeptide Y by 39% but did not alter levels of the other peptides. Continuous quinpirole elevated somatostatin and neuropeptide Y levels (up 43% and 33%, respectively), but reduced the lesion-induced increases in both neurotensin (down 51%) and enkephalin (down 24%) content. Conversely, intermittent quinpirole decreased somatostatin (down 35%) and neuropeptide Y (down 27%), increased neurotensin content by 79% and had no effect on enkephalin. Dynorphin levels were not altered by either continuous or intermittent quinpirole. These findings reveal the complexity of dopaminergic influences on striatal neuropeptides.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Dopaminergic modulation of striatal neuropeptides: differential effects of D1 and D2 receptor stimulation on somatostatin, neuropeptide Y, neurotensin, dynorphin and enkephalin. 135 80

Patients with medically intractable temporal lobe epilepsy (TLE) undergo medial temporal lobectomy with hippocampectomy for one of two reasons. (1) A lesion (tumor or arteriovenous malformation) adjacent to, but not invasive of, the hippocampus, results in the removal of the lesion and adjacent hippocampus in order to ensure a tumor-free margin. This group will be referred to as tumor-related TLE (TTLE) patients. (2) The operation is performed when depth electrode recordings and other evaluative techniques point to the hippocampus as the focus of seizure initiation. This group will be referred to as cryptogenic TLE (CTLE) patients. Analysis of the hippocampi of these two groups of patients reveals that the TTLE hippocampus is quite similar to that of autopsy subjects in its chemical neuroanatomy. However, the dentate gyrus of the CTLE patients shows considerable morphological and cytochemical reorganization. This reorganization is characterized by a number of features. (1) There is a loss of granule cells which occurs either as a patchy loss and/or a thinning of the granule cell layer. (2) Remaining granule cells which contain dynorphin appear to produce recurrent collaterals into the inner molecular layer of the dentate gyrus. (3) In the subgranular region of the hilus (the polymorphic layer) there is a selective loss of interneurons immunoreactive for somatostatin, neuropeptide Y and substance P. (4) There appears to be an increase in fibers immunoreactive for somatostatin and neuropeptide Y which extend throughout the dentate molecular layer. Somatostatin fibers being less numerous than neuropeptide Y fibers (5). The distributions of a number of neurotransmitter receptors also show striking reorganization in the dentate gyrus of the CTLE hippocampus. (6) Second messenger systems protein kinase C and adenylate cyclase, and Na+, K(+)-ATPase activity, as determined by ouabain binding, is increased in the molecular layer of CTLE. This remodeling of the CTLE hippocampus may hold the key to the mechanisms of hyperexcitability of the granule cells in the hippocampus of this group, and consequently the generation of seizures. The removal of the hippocampus in CTLE patients results in good control of seizures, whereas removal of hippocampi that do not show such reorganization, in a group of patients classified as atypical CTLE patients, results in inadequate seizure control. These findings suggest a complex series of processes in converting the properly regulated granule cells into hyperexcitable ones.
 ...
PMID:Neurotransmitters and their receptors in human temporal lobe epilepsy. 136 31

Specimens of the sigmoid colon were obtained from male and female patients (n = 11) with carcinoma of the colon or rectum and studied immunohistochemically for vasoactive intestinal polypeptide-, somatostatin-, substance P-, neuropeptide Y-, calcitonin gene-related peptide-, met- and leu-enkephalin-, 5-hydroxytryptamine-, and dopamine beta-hydroxylase-containing nerves. In the subdivisions of the submucous plexus (namely, Schabadasch's, Meissner's, and the intermediate plexuses), substance P- and vasoactive intestinal polypeptide-immunoreactive nerve fibers were the most numerous, and equal densities of these nerves were found in all three layers. In contrast, few neuropeptide Y-, met-enkephalin-, leu-enkephalin-, calcitonin gene-related peptide-, somatostatin-, 5-hydroxytryptamine-, and dopamine beta-hydroxylase-immunoreactive nerves were found in these regions. The nerve cell bodies of the submucous plexus contained vasoactive intestinal polypeptide, substance P, leu-enkephalin, somatostatin, and 5-hydroxytryptamine but not neuropeptide Y, met-enkephalin, calcitonin gene-related peptide, and dopamine beta-hydroxylase. Vasoactive intestinal polypeptide-containing nerve cell bodies were found in all three subdivisions. Substance P-, leu-enkephalin-, and somatostatin-immunoreactive nerve cell bodies were found in Schabadasch's plexus and the intermediate region of the submucous plexus, but they were absent from Meissner's plexus; 5-hydroxytryptamine-containing nerve cell bodies were only observed in Schabadasch's plexus. The possible function of the neuropeptide-, dopamine beta-hydroxylase-, and 5-hydroxytryptamine-containing neurons in the different layers of the submucous plexus is discussed.
 ...
PMID:Peptide-containing neurons in different regions of the submucous plexus of human sigmoid colon. 848 77

We examined the effects of ciliary neurotrophic factor (CNTF) and depolarization, two environmental signals that influence noradrenergic and cholinergic function, on neuropeptide expression by cultured sympathetic neurons. Sciatic nerve extract, a rich source of CNTF, increased levels of vasoactive intestinal peptide (VIP), substance P, and somatostatin severalfold while significantly reducing levels of neuropeptide Y (NPY). No change was observed in the levels of leu-enkephalin (L-Enk). These effects were abolished by immunoprecipitation of CNTF-like molecules from the extract with an antiserum raised against recombinant CNTF, and recombinant CNTF caused changes in neuropeptide levels similar to those of sciatic nerve extract. Alterations in neuropeptide levels by CNTF were dose-dependent, with maximal induction at concentrations of 5-25 ng/ml. Peptide levels were altered after only 3 days of CNTF exposure and continued to change for 14 days. Depolarization of sympathetic neuron cultures with elevated potassium elicited a different spectrum of effects; it increased VIP and NPY content but did not alter substance P, somatostatin, or L-Enk. Depolarization is known to block cholinergic induction in response to heart cell conditioned medium and we found that it blocked the induction of choline acetyltransferase (ChAT) and peptides by recombinant cholinergic differentiation factor/leukemia inhibitory factor (CDF/LIF). In contrast, it did not antagonize the effects of CNTF on either ChAT activity or neuropeptide expression. Thus, while CNTF has effects on neurotransmitter properties similar to those previously reported for CDF/LIF, the actions of these two factors are differentially modulated by depolarization, suggesting that the mechanisms of cholinergic and neuropeptide induction for the two factors differ. In addition, in contrast to CDF/LIF, CNTF did not alter levels of ChAT, VIP, substance P, or somatostatin in cultured dorsal root ganglion neurons. These observations indicate that CNTF and depolarization affect the expression of neuropeptides by sympathetic neurons and provide evidence for an overlapping yet distinct spectrum of actions of the two neuronal differentiation factors, CNTF and CDF/LIF.
 ...
PMID:Effects of ciliary neurotrophic factor (CNTF) and depolarization on neuropeptide expression in cultured sympathetic neurons. 137 70

The effect and mode of action of vasoactive intestinal polypeptide (VIP), a peptidergic neuromodulator in the gastrointestinal nervous system, were investigated in isolated muscle strips of the guinea-pig ileum. VIP induced concentration-dependent (20 nM-1 microM) contractions of longitudinal ileal strips. TTX (1 microM), a mixture of atropine (3 microM) and spantide (30 microM), a mixture of atropine (3 microM) and omega-conotoxin GVIA (100 nM), somatostatin (60 nM) and dynorphin (100 nM) abolished the effect of VIP. In most cases a small relaxation became evident. Desensitization to substance P in the presence of atropine prevented VIP-induced contraction. A partial inhibition was observed in the presence of atropine (3 microM), spantide (30 microM), omega-conotoxin GVIA (100 nM), beta-endorphin (265 nM), met-enkephalin (1100 nM) and a mixture of spantide (30 microM) and omega-conotoxin GVIA (100 nM). The action of VIP was not significantly modified by guanethidine (3 microM) or hexamethonium (150 microM). In circular ileal strips VIP (10-300 nM) caused concentration-dependent relaxations through a direct myogenic effect. These results indicate that the VIP produced contractions of the guinea-pig ileum are exclusively neurally mediated and involve a cholinergic as well as a noncholinergic-nonadrenergic (NANC) pathway. It is concluded that besides acetylcholine (Ach) VIP releases the peptidergic transmitter substance P from postganglionic nerve fibers of myenteric plexus. Opioid peptides and somatostatin modulate the activity of cholinergic and peptidegic nerves in the guinea-pig ileum. The release of substance P appears to depend completely on N-type voltage sensitive calcium channels.
 ...
PMID:Vasoactive intestinal polypeptide induces neurogenic contraction of guinea-pig ileum. Involvement of acetylcholine and substance P. 137 93

The hypothalamo-neurohypophyseal tract is known to contain the classical neurohypophyseal hormones vasopressin and oxytocin. Additionally, dynorphin, methionine- and leucine-enkephalin, cholecystokinin (CCK), corticotropin-releasing factor (CRF), and galanin are co-stored with vasopressin and/or oxytocin. Recent immunohistochemical studies have revealed the existence of a low to moderate number of substance P-, vasoactive intestinal peptide (VIP)-, neuropeptide Y (NPY)- and somatostatin-immunoreactive nerve fibers within the rat neurohypophysis. VIP-, substance P- and NPY-immunoreactive fibers were distributed throughout the organ, whereas somatostatin-immunoreactive fibers were present in the proximal part of the organ. The positive nerve endings were either large in size resembling classical nerve terminals related to perivascular spaces, or smaller similar to peptidergic fibers as described in the CNS. These results indicate that these neuropeptides may be either co-stored with the classical neurohypophyseal hormones or contained in another system of afferents to the organ. The probably distinct functional roles of these neuropeptides in the physiology of the neurohypophysis are discussed.
 ...
PMID:Non-vasopressinergic, non-oxytocinergic neuropeptides in the rat hypothalamo-neurohypophyseal tract: experimental immunohistochemical studies. 138 83


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