Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.1 (chymotrypsin)
 10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The venom of V. cincta contains acetylcholine (ACh), histamine and 5-hydroxytryptamine (5-HT). Blockers of these agonists did not block completely the hypotensive and smooth muscle contractile activity of venom. On smooth muscle, there was a residual slow contraction. The active substance which produced this slow contraction was separated by solvent extraction, gel filtration and TLC. The purified material (which has been provisionally designated "Vecikinin") lowered cat, rat and guinea pig blood pressure, increased amplitude of cardiac contraction, and increased capillary permeability. Vecikinin contracted several smooth muscle preparations (rat uterus, rat ascending colon, guinea pig ileum, guinea pig colon and rat ileum), while relaxing rat duodenum. Its contractile activity was not lost on boiling, but acid or alkali-boiling reduced its contractile activity. It was inactivated on incubation with chymotrypsin and carboxypeptidase but not with trypsin, pepsin or leucine aminopeptidase. It is a peptide, appears to be of low molecular weight, and could be distinguished from substance P, angiotensin, bradykinin and hornet or wasp kinin.
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PMID:Isolation, partial purification and pharmacodynamics of a slow contractile substance in the venom sac extract of the wasp Vespa cincta Fabr. 240 29

A bland procedure, conducted in ice, is described for the extraction with HCl of smooth-muscle-contracting substances from plexus-containing ileal longitudinal muscle (l.m.) sheets obtained mainly from rabbits and some guinea-pigs. The spasmogenic activity in rabbit extracts was distinguished from acetylcholine, histamine and 5-hydroxytryptamine by antagonists; and from prostaglandins, by its insolubility in ether at acid pH and by pretreatment of the animals with indomethacin. The fact that it contracts the separated l.m. of the guinea-pig ileum, whether plexus-containing or plexus-free, and in atropine distinguishes it also from methionine-enkephalin, somatostatin, 13-norleucine motilin, bombesin, and cholecystokinin octapeptide (CCK8). This activity was partially purified, first by several partitions with ether at pH 1.4-2.2 and then by treatment at pH 4.5-5 with lead acetate. The virtual absence of ATP was confirmed by the firefly bioluminescence technique. The guinea-pig-ileum-contracting component in the partially purified extracts was destroyed by pepsin, chymotrypsin and DPCC-treated trypsin, indicating its peptide nature and distinguishing it from oxytocin, vasopressin, bradykinin, etc. In parallel assays the partially purified rabbit extracts were considerably more active than Substance P on jird or rat ascending colons than on the guinea-pig l.m., suggesting the presence of a second spasmogenic component in the extracts. In guinea-pig extracts the partially purified activity was 8-16 times greater when plexus-containing than when plexus-free, pointing to Auerbach's plexus as the source of the activity.
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PMID:Extraction and partial purification of spasmogenic substances in Auerbach's plexus. 242 21

1. The effect of an acid extract of the carp intestinal bulb (ECI) on guinea-pig ileum longitudinal smooth muscle (GPLM) and carp intestinal bulb longitudinal smooth muscle (CIBLM) was examined. 2. ECI caused a concentration-dependent contraction of GPLM and CIBLM. This ECI-induced response was reduced by atropine to 30-40% of the control, indicating that part of the contracting activity of ECI is attributable to acetylcholine. The atropine-resistant contracting activity of ECI was not mediated by histamine, 5-hydroxytryptamine, ATP, ADP, angiotensin II, neurotensin, vasoactive intestinal peptide or an opioid peptide. 3. The active material mediating the atropine-resistant contracting activity is probably a peptide, because the contraction in response to ECI was abolished on incubation with pepsin or alpha-chymotrypsin. 4. [D-Pro2, D-Trp7,9]-substance P, [D-Pro4, D-Trp7,9]-substance P (4-11) decreased the atropine-resistant contracting activity of ECI as did desensitization induced by substance P. 5. On a Sephadex G 25 column, the active material was eluted as one peak. The active fractions were pooled and then applied to another Sephadex G25 column to compare the Ve/Vo value for the active material with those for peptides of known molecular weights. The molecular weight of the active material was estimated to be 1200-1700 (1410 +/- 70, n = 6). 6. The results indicate the presence of a substance P-like peptide in the carp intestinal bulb.
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PMID:Presence of a substance P-like peptide in an acid extract of the intestinal bulb of the carp (Cyprinus carpio). 246 88

Neural pathways from the submucous plexus to the longitudinal muscle of an adjacent segment of isolated guinea-pig ileum were studied. It was found that electrical field stimulation of a strip of submucosa-submucous plexus produced frequency-dependent longitudinal contractions of an intact segment of intestine lying oral to the point of stimulation. The responses were reduced to less than 10% of control by tetrodotoxin, atropine, morphine and chymotrypsin and by desensitization to substance P (SP). The responses were only inhibited by one-third by hexamethonium and were not affected by desensitization to 5-hydroxytryptamine. The effect of desensitization to SP was reversible, but the effect of chymotrypsin was irreversible. SP-induced desensitization and chymotrypsin did not inhibit the twitch response produced by field stimulation of the whole ileal segment. The same results were observed with preparations made from ileal segments that had been extrinsically denervated. The results suggest that intrinsic neurons with processes in the submucous plexus can excite cholinergic and SP-containing neurons in the myenteric plexus, thereby causing the longitudinal muscle to contract.
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PMID:Contractions of the guinea-pig ileum evoked by stimulation of the submucous plexus. 247 May 95

The nature of the inhbitory non-adrenergic non-cholinergic (NANC) neurotransmitter responsible for neurogenic relaxation of rat duodenum was studied with in vitro techniques. Adenosine 5'-triphosphate (ATP)(1 mM), gamma-aminobutyric acid (GABA, 1 mM), dimethylphenylpiperazinium (DMPP, 0.1 mM) and field stimulation (60 V, 2 ms, 0.1 Hz) produced transient relaxation followed by rebound contraction. In contrast vasoactive intestinal polypeptide (VIP) (0.3 microM) and noradrenaline (1 microM) induced relaxation which set in more slowly and lasted longer. Tetrodotoxin (0.85 microM) abolished field stimulation-induced relaxation but not ATP-, VIP- or noradrenaline-induced relaxation. Nucleotide pyrophosphatase (0.25 U/ml), but not the proteolytic enzyme alpha-chymotrypsin (2 U/ml), selectively antagonized NANC relaxation. The rank order of potency of various adenine derivatives for inducing relaxation was adenosine-5'-triphosphate greater than adenosine-5'-diphosphate much greater than adenosine greater than adenosine-5'-monophosphate. ATP-induced relaxation was selectively antagonized by the putative P2 purinoceptor antagonist reactive blue 2, but unaffected by the selective P1 purinoceptor antagonist 8-phenyltheophylline. The duration of ATP- as well as beta-gamma-methylene adenosine-5'-triphosphate (a stable analogue of ATP)-induced relaxation was similar and was unaffected by indomethacin 10 microM (which abolished the rebound contraction). In those preparations whose contractile tone was increased by using a high-K+ medium the ability of ATP to elicit relaxation was markedly reduced, while GABA- and DMPP-induced relaxation was abolished. On the other hand, ATP-, GABA- and DMPP-induced relaxation of the tonic component of 5-hydroxytryptamine (5-HT)(0.1 mM)-induced contraction was similar to that observed in control conditions. These findings add further weight to the proposal that endogenous ATP is involved in determining NANC relaxation of rat duodenum.
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PMID:Further evidence for involvement of adenosine-5'-triphosphate in non-adrenergic non-cholinergic relaxation of the isolated rat duodenum. 299 70

Electrical field stimulation of 5-hydroxytryptamine contracted cat trachea and bronchi in the presence of cholinergic and adrenergic blockade caused relaxation by activating intrinsic nonadrenergic noncholinergic (NANC) inhibitory nerves. Pretreatment of the tissues with the proteolytic enzyme, alpha-chymotrypsin, did not affect NANC inhibitory responses. Relaxations induced by vasoactive intestinal peptide (VIP) were abolished by alpha-chymotrypsin. These results suggest that VIP or related peptides may not act as the NANC inhibitory transmitter in cat airways. However, the possibility remains that peptides not susceptible to degradation by alpha-chymotrypsin may mediate these NANC inhibitory responses.
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PMID:Effect of alpha-chymotrypsin on the nonadrenergic noncholinergic inhibitory system in cat airways. 404 22

1 Increased vascular permeability following electric antidromic stimulation of the rat saphenous nerve was observed in the skin area supplied by the nerve, confirming previous results by other authors.2 The phenomenon was not affected by pretreatment of the rats with diphenhydramine, burimamide or their combination; atropine, methysergide, methysergide plus diphenhydramine, carboxypeptidase B, acetylsalicylic acid, indomethacin or methiazinic acid. It was partially reduced by previous injection of cellulose-sulphate, a kininogen-depleting agent.3 Perfusates from the subcutaneous tissue of the paw area supplied by the saphenous nerve contained permeability increasing activity as shown by intradermal tests in other rats. This activity was present in perfusates collected during nerve stimulation but not in those collected before stimulation. It was not destroyed by heating to 100 degrees C, or by alpha-chymotrypsin or trypsin.4 Bradykinin-like activity may appear later in the perfusates, depending on the intensity of the stimuli.5 It is concluded that following electrical antidromic stimulation of the saphenous nerve a permeability increasing factor is released, possibly from nerves. It is dialysable and can be distinguished from acetylcholine, histamine, 5-hydroxytryptamine, plasma kinins, substance P, prostaglandins and high molecular weight proteins. The increased vascular permeability induced by this factor leads to plasma exudation and activation of the kinin system.
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PMID:Formation of a factor increasing vascular permeability during electrical stimulation of the saphenous nerve in rats. 414 38

1. The conditions in which the release of an active, bradykinin-like agent occurred when rat paws were heated to 46 degrees C were studied by means of the double coaxial perfusion of the subcutaneous spaces.2. The active material thus released stimulated the isolated rat uterus, produced a relaxing effect on the isolated rat duodenum, was destroyed by incubation with chymotrypsin and was potentiated by bradykinin-potentiating factor. LSD-25, in doses sufficient completely to block 5-hydroxytryptamine, did not affect the responses of the isolated uterus to the active material.3. The effects on this release of anti-proteases and hexadimethrine bromide, atropine and diphenhydramine were studied.4. Soy-bean trypsin inhibitor and hexadimethrine bromide added to the perfusion fluid produced a potent and reversible inhibition of the release of the active material; aprotinin and Kunitz inhibitor caused a temporary block.5. When administered intravenously, much larger doses of the substances were necessary to produce a similar block.6. Pretreatment of the animals with atropine plus diphenhydramine did not affect the release of the active kinin(s).7. Ligature of one iliac artery was followed by disappearance of the active material in the perfusate from the corresponding paw.8. These facts suggest that heating elicits a process leading to plasma extravasation and that the subcutaneous tissue is the chief site of release of the active material.
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PMID:Effect of anti-proteases and hexadimethrine bromide on the release of a bradykinin-like substance during heating (46 degrees C) of rat paws. 531 23

Electrical field stimulation of the isolated pig bladder neck preparation initiated rapid non-adrenergic, non-cholinergic nerve-mediated relaxations. A wide range of substances were examined as possible candidates for the neurotransmitter involved. Of these, only 5-hydroxytryptamine, vasoactive intestinal polypeptide, adenosine and adenosine 5'-triphosphate produced relaxations. Noradrenaline, acetylcholine, substance P, bradykinin and angiotensin II caused contraction, while neurotensin, somatostatin, bombesin and gamma-amino butyric acid were without effect. The nerve response was not blocked by methysergide, ketanserin, chymotrypsin, apamin or 8-phenyltheophylline, although methysergide antagonised the responses to 5-hydroxytryptamine, chymotrypsin blocked the responses to VIP, and 8-phenyltheophylline antagonised the responses to adenosine and ATP.
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PMID:A novel non-adrenergic, non-cholinergic nerve-mediated relaxation of the pig bladder neck: an examination of possible neurotransmitter candidates. 614 1

We report a case of bullous mastocytosis in a 30-month-old girl, who developed disseminated pruritic urticarial and bullous lesions on the trunk accompanied by episodes of vomiting and generalized flushing. Her problems began at the age of 6 months. Her stool was repeatedly positive for occult blood. Histamine and 5-hydroxytryptamine were measured in the urine and serum; urine 5-hydroxytryptamine levels were elevated. In addition, trypsin and chymotrypsin levels were raised in the blister fluid. Metachromatic staining of the mast cells in a skin biopsy specimen confirmed the diagnosis. A combination of oral disodium cromoglycate and ketotifen produced a dramatic improvement of the cutaneous and gastrointestinal features.
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PMID:[Bullous mastocytosis in a child]. 917 60


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