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)

1. The effect of 10-day treatment with growth hormone (GH) (1 mg/kg body weight day) and somatostatin (SRIF) (0.25 mg/kg body weight day) subcutaneously on the activity of muscarinic (M) receptors in rat hypothalamic, pituitary and cerebral cortical membrane fractions was studied using (3H)quinuclidinyl benzylate [(3H)QNB] as radioligand. 2. The administration of GH and SRIF significantly decreased the M-receptor binding affinity in the hypothalamus. 3. In the pituitary the M-receptor affinity was increased after both GH and SRIF treatment. 4. In the hypothalamus and the pituitary the binding capacity of muscarinic receptors was unchanged. 5. In the cerebral cortex the chronical GH injection induced an increase in the number of antagonist binding sites and a decrease of their affinity, while the similar SRIF treatment led to an increase of the binding affinity without any change of M-receptor capacity. 6. These results indicate that GH and SRIF selectively and region-specifically modulate muscarinic receptor binding affinity and capacity and provide new insight into the feedback regulatory mechanisms of GH secretion.
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PMID:Muscarinic receptor activity change after prolonged treatment with growth hormone and somatostatin. 198 Aug 68

The cellular localization of muscarinic acetylcholine binding sites (mAChr) in relation to immunohistochemically characterized cell populations within the rat caudate nucleus has been determined using in vitro autoradiography of the reversible antagonist ligand, quinuclidinyl benzilate [( 3H]QNB). The pattern of autoradiographic silver grain deposition in the striatum was contrasted with the localization of two peptide-containing neuronal populations in the striatum. Substance P-immunoreactive somata demonstrated prevalent association of mAChr binding sites, as did somatostatin-immunoreactive cells. Substantially more striatal muscarinic binding sites were aggregated over the somatostatin interneuron population of the caudate nucleus than were associated with the substance P somata in concurrently performed experiments. This data further substantiates the heterogeneity in organization of the caudate nucleus, and the results are discussed in relation to the processing of information within this basal ganglia region.
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PMID:Striatal muscarinic receptors are associated with substance P and somatostatin containing neurons. 247 12

This report about muscarinic M1 receptors involved in gastric secretion includes two preliminary summaries concerning: a) gastric secretion regulation and b) the evaluation of our knowledge on muscarinic receptors. Gastric secretion is related to secreting cell masses, chief cell and parietal cell masses, and involves some stimulant compounds such as acetylcholine, gastrin and histamine. The schemes of acid secretion stimulation are based on the interactions between these substances. Parietal cells would have specific receptors for each stimulant or histamine would be the final common mediator for all stimulants. Another scheme can be proposed in which gastrin activity would be related to an antagonism between inhibition effects of somatostatin and the suppression of this inhibition by an histamine-like mediator called antramine. The presence of two different receptors to acetylcholine has been demonstrated for long ago, nicotinic receptors (N) and muscarinic receptors (M.). Studies with agonist and antagonist compounds have allowed to distinguish M1 receptors in autonomic ganglia cells and M2 receptors in skeletal muscle. This difference between M and M receptors might be explained by the conformational structure of the receptors (fig. 1), which has also been used for understanding spatial conformation of the agonists and the antagonists (fig. 2, 3). Pharmacological evidence for distinct M1 and M2 muscarinic receptors was presented in 1978 by Goyal and Rattan; in addition receptor binding studies of atropine and acetylcholine have demonstrated that muscarinic antagonists do not distinguish receptor subtypes while agonists do it (fig. 4). Pirenzepin is a new gastric antisecretory tricyclic compound proposed for the treatment of peptic ulcer. It has a higher affinity for M1 receptors in some tissues (eg autonomic ganglia, cerebral cortex) than in other tissues (eg cardia muscle, smooth muscle from gastrointestinal tract). Low concentrations of pirenzepine displace radiolabeled ligands such as 3H QNB, in certain tissues with high affinity receptors, whereas much higher concentrations of pirenzepine are needed to displace these muscarinic antagonist in other tissues with low-affinity receptors (fig. 5). Pharmacological properties of pirenzepine are different from those of atropine (tab. I). Receptor binding studies have disclosed the ability of pirenzepine to discriminate between muscarinic receptors in different tissues. The lowest Ki, molar concentrations producing half-saturation of receptors, was found in autonomic ganglia, reflecting the great affinity of pirenzepine for the neural muscarinic receptor of this tissue (fig. 6).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[MI cholinergic receptors of gastric secretion: current status]. 286 50

Barrel rotation is a motor response observed in rats in which the animal twists about its long axis and rolls laterally. This response was first described following intracerebroventricular injection of somatostatin. The pharmacologic specificity of the response has been questioned, and its physiologic basis is unknown. Recently, barrel rotation following intraventricular injection of quaternary chlorpromazine, chlorpromazine methiodide (CPZMI), has been reported. We have studied the specificity and pharmacologic basis of CPZMI-induced barrel rotation. The response was not induced by 26 compounds injected as controls, and was induced by 6 anti-muscarinic compounds. Dose-response relationships for onset, duration and magnitude of CPZMI-induced barrel rotation response were studied; number of rotations increased linearly with CPZMI dose up to 20 micrograms, after which number of rotations decreased and toxic effects (sedation, seizures) occurred. CPZMI barrel rotation was inhibited by intraventricular injection of the muscarinic agonist carbachol and enhanced by intraventricular or systemic atropine. Muscarinic and dopamine receptor studies indicated that CPZMI has high affinity for the muscarinic cholinergic receptor and low affinity for the spiperone binding site. Modified Scatchard analysis of CPZMI displacement of [3H]QNB at the muscarinic receptor is consistent with muscarinic antagonist properties. We conclude that CPZMI-induced barrel rotation has a specific pharmacologic basis, that of muscarinic cholinergic antagonism.
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PMID:Chlorpromazine methiodide-induced barrel rotation: an antimuscarinic effect. 713 12

Although Rolling mouse Nagoya (RMN) has been considered to demonstrate cerebellar dysfunction, our previous metabolic and electrophysiological studies also revealed a dysfunction of the basal ganglia, with the presumable primary site of dysfunction being the striatum. In the present study, we investigated the neurochemical functions of the striatum. In RMN, both preproenkephalin mRNA and preprotachykinin mRNA increased significantly in the striatum, with unaltered GAD mRNA, [(3)H]spiperone binding, [(3)H]QNB binding and preprosomatostatin mRNA, thus indicating the dysfunction of striatal projection neurons. These findings support the hypothesis that the site of primary dysfunction in the basal ganglia is in the striatum of RMN.
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PMID:Increased preproenkephalin mRNA and preprotachykinin mRNA in the striatum of Rolling mouse Nagoya. 886 30