Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of streptozotocin-induced diabetes on the function and pattern of innervation of the rat parotid gland were investigated. An in vitro preparation was used to measure amylase release and immunohistochemistry was used to examine the innervation of the gland. Basal amylase release and the response to field stimulation were reduced in diabetic animals. In the presence of atropine or a propranolol/phentolamine mixture both control and diabetic responses were attenuated. When all 3 antagonists were present the response to field stimulation (non-adrenergic, non-cholinergic [NANC] response) was about 30% of maximal in untreated rats but virtually abolished in diabetic animals. Substance P (SP), vasoactive intestinal polypeptide (VIP) and neuropeptide Y (NPY) all stimulated amylase release in untreated rats. However, in diabetic rats the responses to all 3 peptides were reduced. No differences in staining were observed between control and diabetic rats with antisera to tyrosine hydroxylase, substance P. VIP or calcitonin gene-related peptide. In contrast there was a marked reduction in NPY-like immunoreactivity in the acinar tissue of diabetic rats. These data suggest that the diabetic rats had a failure of NANC transmission which appears to be due to a reduced NPY innervation and a lack of responsiveness to peptidergic (SP, VIP and NPY) agonists.
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PMID:The effects of streptozotocin-induced diabetes on the peptidergic innervation and function of the rat parotid gland. 247 75

The output of amylase into saliva secreted after injection of methacholine or substance P was increased after parasympathetic denervation, but the salivary concentration of amylase was unchanged. The increased output corresponded to the increased flow. Isoprenaline injected during the methacholine-induced secretion raised the output, more being secreted from the denervated than from the contralateral gland. Vasoactive intestinal peptide, given while substance P caused salivation, also increased the amylase output, but equally from the two glands.
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PMID:Secretion of amylase from the rat parotid salivary gland after degeneration of the auriculotemporal nerve. 248 19

The present study investigates the inhibitory effect of the novel potent benzodiazepine-related CCK-antagonist L-364,718 on pancreatic growth in the rat induced by chronic administration of caerulein and bombesin-like peptides. Caerulein, injected s.c. twice daily at a dose of 1 microgram/kg body weight, and bombesin (10 micrograms/kg) induced a similar increase (1.5-3-fold) in pancreatic wet weight, total protein, amylase, trypsin, putrescine and spermidine content after 14 days of treatment. Growth induced by caerulein showed a significant increase in total DNA content suggesting cellular hyperplasia, whereas bombesin-like peptides led to cellular hypertrophy. In comparison to bombesin the decapeptide neuromedin C (10 micrograms/kg) was found to be 30-50% less potent. In the same dose range, neuromedin B and the tachykinins neurokinin A and B, all structurally related to bombesin, had no significant trophic effect on the rat pancreas. Administration of the CCK-antagonist L-364,718 twice daily at a dose of 0.1 mg/kg or at 1.0 mg/kg, either s.c. or orally, led dose-dependently to a near-complete inhibition of the caerulein-induced trophic effect. In contrast, L-364,718 administered at identical dosages, did not affect pancreatic hypertrophy induced by bombesin and neuromedin C. It is concluded that both peptides mediate their effect on the rat pancreas directly and not via release of endogenous cholecystokinin. Tachykinins are not involved in the regulation of pancreatic growth. Caerulein- and bombesin-like peptides have comparable effects on the stimulation of protein and polyamine synthesis.
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PMID:CCK-antagonist L-364,718: influence on rat pancreatic growth induced by caerulein and bombesin-like peptides. 254 30

The GRP receptor mediated growth response in Swiss 3T3 cells has been used to identify BN/GRP antagonists. Analysis of bombesin antagonism by substance P analogues and by truncated GRP analogues revealed that deletion of the C-terminal methionine residue was important for antagonism. Des-Met analogues showing potent antagonist activity in the in vitro 3T3 system (IC50 approximately 2nM) were synthesized. Further structural modification of these peptides led to the identification of (CH3)2CHCO-His-Trp-Ala-Val-D-Ala-His-Leu-NHCH3 (ICI 216140) which reduced bombesin-stimulated rat pancreatic amylase secretion to basal levels when administered subcutaneously at 2.0 mg per kg.
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PMID:N-isobutyryl-His-Trp-Ala-Val-D-Ala-His-Leu-NHMe (ICI 216140) a potent in vivo antaconist analogue of bombesin/gastrin releasing peptide (BN/GRP) derived from the C-terminal sequence lacking the final methionine residue. 255 38

Specific binding sites for vasoactive intestinal polypeptide (VIP) were characterized in dispersed rat parotid acini. The binding of [125I]VIP was rapid, saturable, reversible, and temperature dependent. Scatchard analysis indicated two functionally independent classes of receptor sites: 41,000 high affinity-low capacity sites per cell with a dissociation constant (Kd) of 6.4 nM and 420,000 low affinity-high capacity sites per cell with a Kd of 150 nM. A peptide with N-terminal histidine and C-terminal isoleucine and secretin, which are structurally related to VIP, inhibited the tracer binding 30 and 200 times less strongly, respectively, than VIP. Epinephrine and carbachol did not inhibit [125I]VIP binding to parotid acinar cells. VIP stimulated cAMP accumulation in parotid lobules and induced amylase secretion in a dose-dependent manner. A peptide with N-terminal histidine and C-terminal isoleucine and secretin were less potent than VIP regarding cAMP accumulation (1/12 and 1/80 of VIP, respectively) and amylase secretion (1/40 and 1/500 of VIP, respectively). Substance P did not stimulate cAMP accumulation but stimulated amylase secretion more strongly than VIP. These observations clearly demonstrated the presence of VIP receptors coupled to adenylate cyclase system in the rat parotid gland, which plays an important role in the regulation of the amylase secretion. The regulation of parotid function by VIP was independent of the adrenergic or muscarinic regulatory system and of the influence of substance P.
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PMID:Vasoactive intestinal peptide binding to specific receptors on rat parotid acinar cells induces amylase secretion accompanied by intracellular accumulation of cyclic adenosine 3'-5'-monophosphate. 257 85

The present study was done both in vivo by cannulating pancreatic duct of rats and in vitro using pancreatic slices and dissociated acini to determine the mode of action of endogenous opiate peptides on pancreatic acinar cell. Pancreatic slices were incubated with beta-endorphin or (Met)5-enkephalin alone and in combination with CCK8. Dissociated acini were incubated with naloxone, substance P, VIP, (Met)5- and (Leu)5-enkephalin and alpha-, beta-, and gamma-endorphin alone or in combination with CCK8. In vivo, both beta-endorphin and (Met)5-enkephalin did not alter basal secretion but inhibited CCK8-stimulated amylase secretion. This effect was not reversed by administration of naloxone. In the slices, neither beta-endorphin nor (Met)5-enkephalin altered basal or CCK8-stimulated secretion. In the dissociated acini, substance P and VIP significantly increased amylase secretion, whereas naloxone, enkephalins, and endorphins failed to alter amylase secretion. CCK8 increased amylase secretion greater than sixfold. In combination with enkephalins and endorphins, there was neither inhibition nor potentiation of CCK8 effect. These data indicate that the effect of opiate peptides on pancreatic acinar cells in the rat are nonspecific and appear not to be mediated by opiate receptors.
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PMID:Effect of endorphins on amylase secretion from rat pancreas in vivo and in vitro. 257 22

The marked increase in the amylase secretion that occurs in parasympathetic saliva some days after sympathetic ganglionectomy occurred after decentralization also; hence, it results from lack of impulses from the central nervous system. It occurred whether salivation was evoked by activating muscarinic receptors with methacholine, peptidergic receptors with substance P or physalaemin, or alpha-adrenoceptors with phenylephrine. Unilateral operation affected to some degree the contralateral gland also.
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PMID:Amylase in parotid saliva of rats after sympathetic nervous decentralization. 258 35

The effects of extracellular ATP on intracellular free calcium concentration [( Ca2+]i), phosphatidylinositol (PtdIns) turnover, amylase release and Ca2+-activated membrane currents were examined in isolated rat parotid acinar cells and contrasted with the effects of receptor agonists known to activate phospholipase C. ATP was more effective than muscarinic and alpha-adrenergic agonists and substance P as a stimulus for elevating [Ca2+]i (as measured with quin2). The ATP effect was selectively antagonized by pretreating parotid cells with the impermeant anion-exchange blocker 4,4'-di-isothiocyano-2,2'-stilbenedisulphonate (DIDS), which also inhibited binding of [alpha-32P]ATP to parotid cells. By elevating [Ca2+]i, ATP and the muscarinic agonist carbachol both activated Ca2+-sensitive membrane currents, which were measured by whole-cell and cell-attached patch-clamp recordings. However, there were marked contrasts between the effects of ATP and the receptor agonists linked to phospholipase C, as follows. (1) Although the combination of maximally effective concentrations of carbachol, substance P and phenylephrine had no greater effect on [Ca2+]i than did carbachol alone, there was some additivity between maximal ATP and carbachol effects. (2) Intracellular dialysis with guanosine 5'-[beta-thio]diphosphate did not block activation of ion channels by ATP, but did block channel activation by the muscarinic agonist carbachol. This suggests that a G-protein is involved in the muscarinic response, but not in the response to ATP. (3) Despite its pronounced effect on [Ca2+]i, ATP had little effect on PtdIns turnover in these cells, in contrast with the effects of carbachol and other Ca2+-mobilizing agents. (4) Although ATP was able to stimulate amylase release from parotid acinar cells, the stimulation was only 33 +/- 9% of that obtained with phospholipase C-linked receptor agonists. These differences suggest that ATP increases [Ca2+]i through specific activation of a pathway which is distinct from that shared by the classical phospholipase C-linked receptor agonists.
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PMID:Extracellular ATP increases free cytosolic calcium in rat parotid acinar cells. Differences from phospholipase C-linked receptor agonists. 284 7

Bradwejn and De Montigny have recently shown that benzodiazepines selectively inhibit excitation of hippocampal neurones by cholecystokinin (CCK). We show here that lorazepam and chlordiazepoxide selectively inhibit the nerve-mediated response of ileal longitudinal muscle to CCK, but have no effect on the direct stimulation of gall-bladder muscle or pancreatic acini by this peptide. Lorazepam (1 and 10 microM) and chlordiazepoxide (0.1 and 1 microM) inhibited responses of guinea-pig ileum, but not gall-bladder to CCK. Responses of both tissues to acetylcholine (ACh) were unaffected and lorazepam (10 microM) did not inhibit ileal responses to neurotensin, 5-hydroxytryptamine and substance P which act entirely or in part by stimulating myenteric nerves. Chlordiazepoxide (1 and 10 microM) did not inhibit CCK-stimulated amylase release from dispersed rat pancreatic acini. Higher concentration of the same drugs and diazepam (1 and 10 microM) which has high affinity for benzodiazepine receptors on gastrointestinal muscle, inhibited responses of ileum and gall-bladder to both CCK and acetylcholine.
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PMID:Effects of benzodiazepines on responses of guinea-pig ileum and gall-bladder and rat pancreatic acini to cholecystokinin. 287 44

The aim of the present work was to study the effect of substance P (SP) and somatostatin (SST) on hepatic bile flow. For this purpose a total of 54 anesthetized mongrel dogs were used. The gallbladder was excluded by ligation of the cystic duct and a common duct fistula was created by insertion of a catheter into the common duct. Both SP and SST were found to exert an anticholeretic effect in the dog. SST was also found to be anticholeretic in man. In the dog, SP was infused at dosages from 0.5-20 ng kg-1 min-1 and exerted a significant anticholeretic effect at a dosage of 2.5 ng or higher. At dosages of 2.5 and 20 ng kg-1 min-1, SP decreased the basal bile secretion by about 20 and 40% respectively. The decrease in bile flow was accompanied by decreased outputs of sodium, potassium, chloride, bicarbonate and amylase. With taurocholate-stabilized and taurocholate-stabilized and hormone-induced bile secretion, SP had the above mentioned effects and in addition the output of bile acids decreased. The effect of SP occurred within minutes and after withdrawal of SP there was a positive rebound effect, with a magnitude of about 30% following the 20 ng dosage. SST at dosages from 20-1000 ng kg-1 min-1 induced an anticholeretic effect with a magnitude of 10-25%. With both basal and taurocholate-stabilized bile secretion, the outputs of bile, bile acids and electrolytes decreased during the infusion period and remained diminished for 10-20 min after termination of the infusion. Unlike SP, SST had no anticholeretic effect in the presence of CCK or secretin. A simultaneous infusion of SP and SST decreased bile flow more than either agent alone. The anticholeretic effect of SST was verified in five patients. They had all been operated on for choledocholithiasis. In four patients a complete diversion of bile was obtained with a Foley catheter in the common duct and in the fifth patient from an impacted stone in the common duct. During infusion of SST, 250 ug h-1, the outputs of hepatic bile and bile acids decreased while the outputs of cholesterol and phospholipids were unchanged. The serum bile acid concentration was unaffected by SST and therefore SST is suggested to exert an inhibitory effect on bile acid synthesis. The changes in electrolyte outputs induced by SST in man corresponded to those in the dog.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Anticholeretic effects of substance P and somatostatin. 608 86


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