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)

The opioid peptides are potent inhibitors of gastric somatostatin-like immunoreactivity (SLI) secretion from the isolated perfused rat stomach. In addition, inhibition of SLI secretion induced by vagal stimulation is partially blocked by naloxone, indicating that endogenously released opioid peptides probably play a physiological role in the regulation of SLI release. The opioid peptides exert their effects by interacting with a number of different receptor types. In the present study, the effect of the selective delta-opioid receptor agonists [D-Pen2.5]enkephalin and [D-Pen2,L-Pen5]enkephalin and the mu-receptor agonist [D-Ala2, N-methyl (NMe)-Phe4,Gly5-ol]enkephalin on gastric inhibitory polypeptide (GIP)-stimulated SLI secretion from the isolated perfused rat stomach have been studied. Responses to the less selective delta-agonist [D-Ala2,D-Leu5]enkephalin, dynorphins 1-8, 1-13, and 1-17, and the extended enkephalin forms Met-enkephalin-Arg6-Phe7,Met- enkephalin-Arg6-Gly7-Leu8, and Met-enkephalin-Arg6-Arg7-Val8-NH2 (metorphamide), have also been investigated. [D-Ala2,NMe-Phe4,Gly5-ol]enkephalin induced a concentration-dependent inhibition of GIP-stimulated SLI secretion, with 50% of maximal inhibition at 10 nM. Neither [D-Pen2.5]enkephalin nor [D-Pen2,L-Pen6]enkephalin (10 nM to 1 microM) had any effect on SLI release, and [D-Ala2,D-Leu5] enkephalin inhibited SLI release only at high concentrations. Met-enkephalin-Arg6-Phe7 and metorphamide both inhibited SLI release, whereas Met-enkephalin-Arg6-Gly7-Leu8 and the dynorphins had little or no effect. In conclusion, the strong inhibition of SLI secretion produced by [D-Ala2,NMe-Phe4,Gly5-ol] enkephalin and lack of major effect of [D-Pen2.5]-enkephalin, [D-Pen2,L-Pen5]enkephalin, and the dynorphins indicate that opioid peptide-induced inhibition was mediated by interaction with mu-receptors and that neither delta or kappa-receptors play a significant role.
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PMID:Characterization of the opioid receptor type mediating inhibition of rat gastric somatostatin secretion. 197 18

1. The mechanical responses to some autonomic drugs and neuropeptides of longitudinal muscle (LM) and circular muscle (CM) strips isolated from the carp intestinal bulb were investigated in vitro. 2. Acetylcholine and carbamylcholine caused concentration-dependent transient contraction of both LM and CM strips. Tetrodotoxin had no effect, but atropine selectively decreased the contractile responses to acetylcholine and carbamylcholine. 3. Excitatory alpha-2 and inhibitory beta adrenoceptors were present in both LM and CM strips. 4. 5-Hydroxytryptamine (5-HT) caused concentration-dependent contraction of both LM and CM strips. Tetrodotoxin, atropine and methysergide decreased the contractile responses to 5-HT. 5. Some neuropeptides (angiotensin I, angiotensin II, bombesin, bradykinin, neurotensin, somatostatin and vasoactive intestinal polypeptide) did not cause any mechanical response (contraction or relaxation) in either smooth muscle strip. 6. Substance P (SP), neurokinin A (NKA) and neurokinin B (NKB) caused contraction of both LM and CM strips. However, the time course of the contraction in LM was different from that in CM. The order of potency was NKA greater than SP greater than NKB in LM strips and NKA greater than SP much greater than NKB in CM strips. In LM strips, the contractile responses to tachykinins were unaffected by spantide and methysergide, but partly decreased by tetrodotoxin and atropine. On the other hand, the contractile responses of CM strips were unaffected by tetrodotoxin, atropine, methysergide and spantide. 7. Dynorphin (1-13) (DYN), leucine-enkephalin (L-Enk) and methionine-enkephalin (M-Enk) caused concentration-dependent contraction of both LM and CM strips. The order of potency was DYN greater than M-Enk greater than L-Enk. Naloxone selectively decreased the responses to opiate peptides. 8. The present results indicate that acetylcholine, carbamylcholine, catecholamines, 5-HT, tachykinins (SP, NKA and NKB) and opiate peptides (DYN, L-Enk and M-Enk) affect the mechanical activity of LM and CM strips isolated from the carp intestinal bulb through their specific receptors.
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PMID:Effects of some autonomic drugs and neuropeptides on the mechanical activity of longitudinal and circular muscle strips isolated from the carp intestinal bulb (Cyprinus carpio). 198 39

The autoradiographic distribution of D1 dopaminergic binding sites was studied in the human ventral mesencephalon using the D1 antagonist [3H]SCH 23390. [3H]SCH 23390 binding was characterized by a single class of sites with a Kd of 2.5 nM and a Bmax of 31 fmol/mg of tissue. The density of [3H]SCH 23390 binding sites was high in the substantia nigra, moderate in the ventral tegmental area and low in the peri- and retrorubral field (catecholaminergic region A8). Binding densities were similar in pars compacta and pars reticulata of the substantia nigra, except for a peak value of high [3H]SCH 23390 in the pars reticulata, at a level just ventral to a zone of hyperdensity of melanized dopaminergic neurons in the pars compacta. The anatomical organization of the human ventral mesencephalon was analysed on adjacent sections stained for acetylcholinesterase histochemistry and tyrosine hydroxylase, substance P, dynorphin B, somatostatin and methionine-enkephalin immunohistochemistry, respectively. The similarity in distribution of [3H]SCH 23390 binding sites and substance P or dynorphin B immunoreactivity suggests that D1 binding sites are mainly located on the striatonigral projections. In accordance with these results: (1) the density of [3H]SCH 23390 binding sites was reduced in the substantia nigra of a patient with Huntington's chorea, a disease associated with a degeneration of striatonigral neurons; (2) the density of [3H]SCH 23390 binding sites was unaffected in the substantia nigra of a patient with Parkinson's disease, a disorder characterized by a marked loss in nigral tyrosine hydroxylase-positive neurons. [3H]SCH 23390 binding sites showed a characteristic, heterogeneous distribution within the human ventral mesencephalon, confirming data obtained in other species. The preferential localization of D1 dopamine receptors on striatonigral projections in human brain suggests that pharmacological manipulation of these receptors modulates the activity of striatonigral pathways, thereby affecting the various outputs of the nigral complex.
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PMID:Microtopography of D1 dopaminergic binding sites in the human substantia nigra: an autoradiographic study. 198 69

The deep dorsal penile vein was obtained from seven patients undergoing surgery for erectile dysfunction. The veins were studied histologically and immunohistochemically for serotonin, dopamine beta-hydroxylase, vasoactive intestinal polypeptide, neuropeptide Y, substance P, calcitonin gene-related peptide, somatostatin, and [Leu]- and [Met]enkephalin. Histologically, the deep dorsal vein was found to be a large muscular vein with a thin endothelial lining. The tunica media was composed of an inner longitudinally and an outer circularly arranged smooth muscle layer. Numerous vasa vasorum (up to 30 in a single transverse section) were found in the tunica adventitia. The greatest density of nerves supplying the deep dorsal vein and vasa vasorum were neuropeptide Y-immunoreactive nerves followed (in a decreasing order) by vasoactive intestinal polypeptide- and dopamine beta-hydroxylase-immunoreactive nerves. Substance P-, calcitonin gene-related peptide- and somatostatin-immunoreactive nerves, but not serotonin-, [Leu]- and [Met]enkephalin-immunoreactive nerves, were occasionally found around the deep dorsal vein. All these nerve fibers were confined to the adventitial-medial border except neuropeptide Y-immunoreactive nerves which in addition penetrated the tunica media to the subendothelial layer of the deep dorsal vein. In contrast, neuropeptide Y-immunoreactive nerves supplying the vasa vasorum were always confined to the adventitial-medial border. The possible function of the medial innervation of the deep dorsal vein by neuropeptide Y-immunoreactive nerves is discussed.
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PMID:The human penis: an unusual penetration of NPY-immunoreactive nerves within the medial muscle coat of the deep dorsal vein. 203 19

Radioimmunoassay (RIA) detected the presence of beta-endorphin in the intraglandular colloid (IGC) of bovine pituitary intermediate lobe origin. The amount of beta-endorphin recovered in each of twelve samples ranged from 0.15 to 218.30 pmol/mg protein. A second group of assays [amino acid analysis, high performance liquid chromatography (HPLC) and mass spectral analysis] confirmed the RIA findings in another series of colloid samples. Approximately 75 pmol was collected from eight pooled glands. beta-Endorphin is an addition to the list of peptide hormones (e.g., methionine-enkephalin, adrenocorticotropin, arginine-vasopressin, alpha-melanocyte-stimulating hormone, beta-lipotropin and somatostatin) previously discovered in IGC by this laboratory.
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PMID:Beta-endorphin in pituitary intraglandular colloid of intermediate lobe origin. 205 96

We concurrently measured, by radioimmunoassay, levels of substance P (SP), somatostatin (SST), methionine-enkephalin (Met-Enk), cholecystokinin (CCK), peptide hystidyl-isoleucine (PHI), vasoactive intestinal polypeptide (VIP), and neuropeptide Y (NPY) in the ventral and dorsal gray matter at each segment of the cervical, thoracic, lumbar, and sacral spinal cord, obtained within 6 hours of death from 4 subjects (ages 17 to 55) with no neurologic disease. Levels (pmol/g gray matter) of SP, SST, and Met-Enk throughout and PHI, VIP, and NPY in lumbar and sacral cord were significantly higher in dorsal than in ventral gray matter. PHI, VIP, and NPY were significantly higher in lumbar and especially sacral cord than in cervical and thoracic segments. In rats, a postmortem delay of up to 8 hours did not affect SP, Met-Enk, PHI, or NPY and decreased SST, CCK, and VIP levels. Thus, there is a characteristic profile of neuropeptide distribution in gray matter, which emphasizes the neurochemical heterogeneity along the rostrocaudal and dorsoventral extent of normal human spinal cord.
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PMID:Segmental analysis of neuropeptide concentrations in normal human spinal cord. 229 59

The localization of Substance P(SP)-, Methionine-Enkephalin(met-Enk)-, Somatostatin(SOM)- Serotonin(SER)-, Cholecystokinin(CCK)-, and Vasoactive intestinal polypeptide (VIP)-like immunoreactivity (-LIR) has been determined immunocytochemically in the thoracic spinal cord intermediate zone of male and female guinea pigs. All neuroactive substances studied are exclusively localized in nerve fibre varicosities and terminals building up the vegetative network of the thoracic spinal cord intermediate zone. This network is situated dorsally to the central canal as a longitudinal plate of approximate thickness of 90-100 microns. Immunoreactive fibres are observed in the two Fasciculi longitudinales laterales and the two Fasciculi longitudinales mediales which are interconnected by transverse and oblique peptide-containing bundles (the terminology used by Petras and Cummings 1972; Galabov and Davidoff 1976). All these bundles interconnect the nuclei intermediolaterales principales and funiculares, the nuclei intercalates spinales and the nuclei intercalates paraependimales in ipsi- and contralateral as well as in rostral and caudal direction. The neurones of these nuclei are surrounded by immunoreactive varicosities and terminals. The quantity of the immunoreactive structures and intensity of the staining varied for the different neuroactive substances. As to the origin of the vegetative network immunoreactive fibres three main possibilities exists: a). From primary afferent neurones situated in the dorsal root ganglia, which send their axons via the dorsal roots (mainly for SP and perhaps for CCK); b). From supraspinal neurones which send their axons descending in the white matter funiculi and in the fasciculi longitudinales laterales and mediales and c). From intrinsic spinal cord neurones, which send their neurites in ascending and descending directions, ipsi- and contralaterally and interconnect the spinal cord segments. The different origin of the vegetative network immunoreactive fibres as well as the complex innervation of the preganglionic sympathetic nerve cells in the intermediate zone of the spinal cord suggests that this network may play an important role in the integration of the central and peripheral vegetative nervous system as well as probably in the integration of the somatic and the vegetative nervous system.
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PMID:Localization of some neuropeptide- and serotonin-like immunoreactivities in the vegetative network of guinea pig spinal cord. 241 Apr 87

The immunofluorescent localization of substance P (SP), somatostatin and methionine enkephalin has been determined in the rat superior cervical ganglion of the sympathetic nervous system. Immunoreactivity was confined to the norepinephrine-containing post-ganglionic neurons and their processes. Nearly 20% of the postganglionic somata demonstrate dual coincidence in staining for SP-somatostatin, somatostatin-enkephalin, or SP-enkephalin. Almost 10% of the positively stained neurons show a coincident staining of all 3 peptide compounds within their somata. This suggests that multiple neurotransmitter chemicals may be employed by the postganglionic cells of the superior cervical ganglion.
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PMID:Peptide coincidence in rat superior cervical ganglion. 241 49

Infusion of neurotensin, substance P and methionine-enkephalin induces colonic contraction in the cat. The present study was performed to investigate the effect of various pharmacological blocking agents on colonic contraction evoked by these peptides infused by the i.a. or i.v. route. The contractions caused by infusions of neurotensin were blocked by tetrodotoxin (1 micrograms kg-1 i.a.), hexamethionium (10 mg kg-1 i.v.), atropine (0.1 mg kg-1 i.v.) or somatostatin (100 pmol min-1 i.a.), but not by haloperidol, methysergide, mepyramine, cimetidine or naloxone. The contractile effect of substance P on the colon was abolished by the substance P receptor antagonist (D-Arg1, D-Pro2, D-Trp7,9, Leu11)-substance P (70 nmol min-1 i.a.). No other blockers used, such as tetrodotoxin, hexamethonium, atropine, mepyramine, cimetidine, methysergide, naloxone or somatostatin inhibited the response to substance P. Methionine-enkephalin produced a colonic contraction that was completely blocked by naloxone (1 mg kg-1 i.a.). Both atropine (0.1 mg kg-1 i.v.) and somatostatin (100 pmol min-1 i.a.) reduced the contractile response. However, tetrodotoxin, hexamethonium, mepyramine, cimetidine and methysergide did not affect the response to methionine-enkephalin. All adrenergic blockers tested, that is, guanethidine, propranolol and phentolamine, increased the contractile responses to the peptides. The results indicate that the colonic contraction induced by neurotensin is mediated via nervous cholinergic pathways. Substance P induces colonic contraction, probably by a direct effect on smooth muscle substance P receptors. Methionine-enkephalin induces colonic contraction which could be blocked by naloxone. However, a cholinergic or peptidergic link may also be involved in the response to methionine-enkephalin.
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PMID:Pharmacological analysis of the mechanism of action for colonic contraction induced by neurotensin, substance P and methionine-enkephalin. 241 19

The distribution of leucine-enkephalin, methionine-enkephalin, neurotensin, somatostatin, substance P, oxytocin, vasopressin, neurophysin II, and serotonin in nerve terminals and fibers of sympathetic autonomic areas of the thoracolumbar (T-L) spinal cord was studied immunohistochemically in cats. Densities of these immunoreactive terminals and fibers were estimated in the intermediolateral nucleus pars principalis (IMLp) and pars funicularis (IMLf), the nucleus intercalatus (IC), and the central autonomic area (CA). Results for leucine- and methionine-enkephalin-like immunoreactivity (ENK) were similar and immunoreactivity for vasopressin was not observed. The greatest numbers of terminals and fibers in the IMLp region contained ENK, neurotensin-(NT), and serotonin-like immunoreactivity (5HT); terminals and fibers containing substance P-(SP) and neurophysin II-like immunoreactivity (NP2) were intermediate in number, and those containing somatostatin-(SS) and oxytocin-like immunoreactivity (OXY) were generally sparse. In the IC and CA, terminals and fibers containing ENK and NT were dense, those containing SP were moderate, and those containing OXY, NP2, and 5HT were sparsely represented. In the IMLp, where the largest proportion of sympathetic preganglionic neurons (SPN) is found, the greatest concentration of terminals and fibers containing ENK was found in segments T1-T8; for NT these segments were T1-T5 and T11-L1, for SP-C8-T2 and T11-L1, for NP2-T4-T7 and L2 to L3, and for 5HT-T1-T5. Terminals and fibers containing SS and OXY were present in segments C8-T10 and segments C8, T2-T8, T13, and L2 to L3, respectively. These results indicate that while ENK, NT, SP, NP2, and 5HT fibers and terminals are widely distributed throughout the T-L cord, they may influence to a greater degree the SPN in segments where they are present in greater numbers. As SS and OXY were not found at all levels of the IMLp, their functions may be more organ specific.
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PMID:Segmental distribution of peptide- and 5HT-like immunoreactivity in nerve terminals and fibers of the thoracolumbar sympathetic nuclei of the cat. 241 41


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