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

The effects of a number of peptides which are found in the gastrointestinal tract have been ascertained on the direct current recorded dorsal and ventral root responses of the isolated hemisected toad spinal cord. Motilin, substance P, bombesin, neurotensin, and thyrotropin releasing hormone had potent depolarizing actions on dorsal root terminals and motoneurons. These substances evoked discernable effects at concentrations as low as 10--7 M, or even lower with motilin. The effects of motilin, neurotensin, and thyrotropin-releasing hormone were greatly reduced or abolished by perfusion of the preparation with tetrodotoxin. Adrenocorticotrophic hormone, secretin, and pancreozymin (cholecystokinin) also depolarized dorsal root terminals and motoneurons. The effects of secretin and cholecystokinin were not abolished by tetrodotoxin. Leu- and Met-enkephalin had weak hyperpolarizing actions on the dorsal and ventral root potentials of repetitively stimulated preparations. Gastrin, gastric inhibitory peptide, glucagon, and somatostatin had no apparent effects on the responses of the preparation. Angiotensin and vasopressin both had rather weak depolarizing effects on the dorsal and ventral roots.
 ...
PMID:Actions of various gastrointestinal peptides on the isolated amphibian spinal cord. 11 60

Vasoactive intestinal peptide (VIP) is a potent and efficient stimulator of adenosine 3':5'-cyclic monophosphate (cAMP) accumulation in a human colon carcinoma cell line, HT 29. cAMP accumulation is sensitive to a concentration of VIP as low as 3x10(-12) M. Maximum VIP-induced cAMP levels were observed with 10(-9) M VIP and are about 200 times above the basal levels. Half-maximum cAMP production was obtained at 3x10(-10) M VIP. (125)I-Labeled VIP was found to bind to HT 29 cells; this binding was competitively inhibited by concentrations of unlabeled VIP between 10(-10) and 10(-7) M. Half-maximum inhibition of binding was observed with 2x10(-9) M VIP. Secretin also stimulated cAMP accumulation in HT 29 cells, but its effectiveness was 1/1000 that of VIP. The other peptides tested at 10(-7) M, such as insulin, glucagon, bovine pancreatic polypeptide, somatostatin, octapeptide of cholecystokinin, neurotensin, and substance P, did not stimulate cAMP accumulation. Prostaglandin E(1) and catecholamines stimulated cAMP production but were 1/2.3 and 1/5.5 as efficient as VIP, respectively. Another malignant cell line from the gut, the human rectal tumor cell line HRT 18, is also sensitive to VIP. In HRT 18 cells, VIP stimulated cAMP accumulation with a maximal effect at 10(-8) M; half-maximum stimulation was observed at about 10(-9) M. These results demonstrate the presence of VIP receptors in two malignant human intestinal cell lines (HT 29 and HRT 18) in culture and provide a model for studying the action of VIP on cell proliferation.
 ...
PMID:Vasoactive intestinal peptide: a potent stimulator of adenosine 3':5'-cyclic monophosphate accumulation in gut carcinoma cell lines in culture. 20 77

We have prepared 125I-labeled physalaemin and have examined the kinetics, stoichiometry, and chemical specificity with which the labeled peptide binds to dispersed acini from guinea pig pancreas. Binding of 125I-labeled physalaemin was saturable, temperature-dependent, and reversible and reflected interaction of the labeled peptide with a single class of binding sites on the plasma membrane of pancreatic acinar cells. Each acinar cell possessed approximately 500 binding sites, and binding of the tracer to these sites could be inhibited by physalaemin [concentration for half-maximal effect (Kd), 2 nM], substance P (Kd, 5 nM), or eledoisin (Kd, 300 nM) but not by cholecystokinin, caerulein, bombesin, litorin, gastrin, secretin, vasoactive intestinal peptide, glucagon, somatostatin, neurotensin, bovine pancreatic polypeptide, leucine-enkephalin, methionine-enkephalin, atropine, or carbamylcholine. With physalaemin, substance P, and eledoisin, there was a close correlation between the relative potency for inhibition of binding of labeled physalaemin and that for stimulation of amylase secretion. For a given peptide, however, a 3-fold higher concentration was required for half-maximal inhibition of binding than for half-maximal stimulation of amylase secretion, calcium outflux, or cyclic GMP accumulation. These results indicate that dispersed acini from guinea pig pancreas possess a single class of receptors that interact with physalaemin, substance P, and eledoisin and that occupation of 45% of these receptors will cause a maximal biological response.
 ...
PMID:Interaction of physalaemin, substance P, and eledoisin with specific membrane receptors on pancreatic acinar cells. 23 Apr 88

Circulatory effects of gastrointestinal hormones and related peptides are surveyed. Only experiments using low peptide dosages, non-extensive surgery and intravenous infusions give relevant data in this field. Glucagon, secretin, vasoactive intestinal peptide, gastrin, cholecystokinin, Substance P and Somatostatin are vasoactive within the splanchnic area, each fraction in a specific pattern.
 ...
PMID:Circulatory effects of gastrointestinal hormones and related peptides. 27 37

The chemistry, localisation, release and effects of gastrointestinal hormones and some related peptides are surveyed. Their main presumed physiologic actions are: gastric acid and pepsin secretion are stimulated by gastrin and to a less degree by secretin. Acid secretion is inhibited by bulbo-enterogastrone and GIP. Biliary water and electrolytes are augmented by gastrin, CCK-PZ, secretin and VIP and inhibited by Substance P. Pancreatic bicarbonate and enzyme secretions are stimulated by secretin and CCK-PZ, especially in combination. Lower oesophageal and antral motility and tonus are elevated following gastrin and motilin; the gallbladder and small intestine empty following CCK. Gastrin regulates gastrointestinal, and CCK pancreatic, tissue growth. Somatostatin inhibits all gut hormones. All peptides are vasoactive within the splanchnic area, each one in a specific manner.
 ...
PMID:Gastrointestinal hormones. 35 98

Using immunohistochemical techniques we studied duodenal biopsies from 18 patients with coeliac disease and 24 patients with normal duodenal morphology. We had access to antisera against the following gastrointestinal peptides: cholecystokinin (CCK), gastric inhibitory peptide (GIP), gastrin-17, glucagon-enteroglucagon, motilin, neurotensin, pancreatic peptide (PP), secretin, somatostatin, substance P and vasoactive intestinal peptide (VIP). The somatostatin, GIP, CCK, and glucagon cells were increased in number in coeliac disease. The number of motilin cells was slightly increased, while secretin cells were reduced. Cells storing gastrin-17, substance P, or neurotensin were rare in all patients regardless of diagnosis. No PP immunoreactive cells were found and VIP was localised to neurons only. In biopsies from patients having a mucosa with ridging of villi the number of the various endocrine cell types did not differ from that in the control group.
 ...
PMID:Duodenal endocrine cells in adult coeliac disease. 38 55

The effects of various polypeptide enterohormones and the tachykinin secretogogue, physalaemin, on electrolyte transport by the main excretory duct of the mandibular gland of the rabbit were studied in vitro. Vasoactive intestinal peptide (VIP, 2 X 10(-11) mol 1(-1)) and gastric inhibitory polypeptide (GIP, 10(-11) mol 1(-1)) reduced nett Na+ movement from lumen to interstitium and VIP also reduced the transepithelial potential difference; the effective concentrations of the two hormones lay within the range of normal plasma concentrations. Gastrin (5 x 10(-7) mol 1(-1)) and synthetic secretin (2 x 10(-7) mol 1(-1)) had similar effects but only at concentrations well above the normal plasma levels. Caerulein, an analogue of the octapeptide of cholecystokinin, had no effect on duct function even at a concentration of 10(-6) mol 1(-1). The potent salivary secretogogue, physalaemin (4 x 10(-8) mol 1(-1)), which is an analogue of Substance P, a putative mammalian enterohormone and neurotransmitter substance, caused a marked increase in ductal Na transport (in rat as well as rabbit). It is concluded that VIP and GIP would normally play a role in determining salivary electrolyte composition and it is postulated that their action may be antagonized by a tachykinin such as Substance P.
 ...
PMID:Modification of salivary duct electrolyte transport in rat and rabbit by physalaemin, VIP, GIP and other enterohormones. 56 44

Secretin, substance P, and vasoactive intestinal peptide (VIP) were studied from the immunological point of view using synthetic hormones and their related peptides which were prepared by the conventional method for peptide synthesis. Immunological properties of these hormones were characterized by radioimmunoassays specific to the respective hormones. Antisecretin antisera (NCC-R-1 and R-801) were generated in rabbits with synthetic porcine secretin absorbed on polyvinylpyrrolidone. Antiserum to substance P (R-400) was produced in a rabbit with synthetic substance P-human alpha-globulin conjugate. Generation of anti-VIP antiserum (R-502) was carried out by immunizing rabbits with synthetic VIP absorbed on polyvinylpyrrolidone. Synthetic polypeptides related to the three hormones that were examined in this study include secretin(4-27), secretin(5-27), secretin(7-27), secretin(11-27), secretin(14-27), secretin(18-27), secretin(1-22)amide, secretin(7-22)amide, Nalpha-tyrosyl-secretin, [1-Tyr]secretin, [4-Ala]secretin, [4-D-Ala]secretin, [4-Ala,5-Val]secretin, [6-Tyr]secretin, substance P(2-11), substance P (3-11), substance P(4-11), substance P(5-11), substance P(6-11), Nalpha-tyrosyl-substance P, [1-Tyr]substance P, [8-Tyr]substance P, [11-Leu]substance P, des-11-Met-substance P, VIP(7-28), VIP(11-28), VIP(18-28), VIP(1-18)amide, and VIP(1-22)AMIDE. The results revealed two antigenic regions at the amino- and carboxylterminal portions of the secretin and VIP molecules. As to substance P, the major antigenic region was located within the 3 to 11 sequence. The proline residue in position 4 and methionine in position 11 seemed to be of special importance. The immunoassays demonstrated the existence of immunoreactivities of these hormones in hot water extracts from various porcine tissues. In the pituitary, VIP and substance P immunoreactivities were detected, whereas secretin was not. Secretin, VIP, and substance P were found in the pancreas, but at low concentrations. Distributions of these hormones in various sites of the gastrointestinal tract were also demonstrated.
 ...
PMID:Immunological aspects of secretin, substance P, and VIP. 83 40

In addition to established gastrointestinal hormones--secretin, cholecystokinin-pancreozymin (CCK-PZ), gastrin, and glucagon---some 30 polypeptides with gastrointestinal actions can be listed. New aspects of these substances include the following: Gastrin and vasoactive intestinal peptide (VIP) can be also encountered in the central nervous system and may act as transmitters. CCK-PZ-serum concentrations are found markedly elevated in patients with exocrine pancreatic insufficiency; this may provide the opportunity to establish a realtively simple screening test. Moreover, there is evidence that serum-CCK-PZ levels serve as satiety signal. Secretin secretion is said to be enhanced in hunger and then to act as a lipolytic hormone. In addition to enteroglucagon, a gastrintestinal peptide identical to pancreatic glucagon has been detected. Gastric inhibitory polypeptide (GIP) inhibits gastric secretion and motility (enterogastrone activity) and together with glucose it stimulates insulin release (incretin activity). Motilin increases lower esophageal sphincter pressure, enhances gastric pepsin secretion and slows down gastric evacuation. Serum levels of pancreatic polypeptide may be found elevated as a diagnostic index in patients with endocrine peptide tumors of the pancreas. Recently, the potential importance of local (paracrine) actions of gastrointestinal polypeptides has been amphasized. Predominantly paracrine activity is exhibited by some prototype hormones, e.g. somatostatin, substance P, bombesian, and the non-polypeptide compounds, prostaglandins.
 ...
PMID:[New views on gastrointestinal hormones]. 85 99

Tachykinins (TK) are family of peptides including substance P (SP), substance K (SK) and neuromedin K (NK) that have been found in the nerves of the gastrointestinal tract and proposed to act as neurotransmitters to affect the motor, secretory and circulatory functions of the gut, but little is known about their action on the pancreas. In this study three series of tests were carried out to determine the action of SP, SK and NK on pancreatic secretion in conscious dogs and amylase release from the dispersed rat pancreatic acini and to correlate the alterations in pancreatic secretory and circulatory effects of TK in anesthetized dogs. SP, SK and NK infused i.v. in graded doses (0.12-1.0 microgram/kg per h) in conscious dogs stimulated pancreatic protein outputs reaching, respectively, 38% and 23% of the maximal response to CCK (40 pmol/kg per h). HCO3- outputs were also significantly increased but the highest response did not exceed about 5% of secretin (328 pmol/kg per h) maximum. Cholinergic blockade by atropine abolished the pancreatic responses to tachykinins. When added at various concentrations (10(-11)-10(-7) M) to the incubation medium of rat dispersed pancreatic acini, SK, SP and NK increased in concentration-dependent manner the release of amylase from the resting pancreatic acini and augmented the enzyme release induced by CCK-8 and by urecholine. In anesthetized dogs infused with a background dose of secretin (82 pmol/kg per h), addition of SP, SK and NK caused an immediate and dose-dependent increase in the pancreatic blood flow, oxygen consumption and pancreatic secretion accompanied by a dose-dependent decrease in arterial blood pressure. This study shows that TK are potent pancreatic circulatory stimulants and moderate secretagogues both in vivo and in vitro, acting, at least in part, via cholinergic pathway.
 ...
PMID:Role of tachykinins in the control of pancreatic secretion and circulation. 128 Apr 85


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