Detail of "5241-71-4"

Reference

Effects of cholecystokinin octapeptides and their fragments on seizures induced by different convulsive drugs

Effects of cholecystokinin octapeptides and their fragments on seizures induced by different convulsive drugs. Kadar, T.; Pesti, A.; Toth, G.; Penke, B.; Telegdy, G. (Dep. Pathophysiol., Univ. Med. Sch., Szeged, Hung.). Neuropept. Psychosom. Processes, Int. Conf. Integr. Neurohumoral Mech., Meeting Date 1982, 231-8. Edited by: Endroczi, Elember. Akad. Kiado: Budapest, Hung. (English) 1983. CODEN: 53HNAO. DOCUMENT TYPE: Conference CA Section: 2 (Mammalian Hormones) The antagonist activities of cholecystokinin octapeptide sulfate ester (CCK-8-SE) [25126-32-3], nonsulfated cholecystokinin octapeptide (CCK-8-NS) [25679-24-7] and fragments of these mols. on convulsive seizures induced by pentetrazole [54-95-5], strychnine [57-24-9], and picrotoxin [124-87-8] were examd. in mice and rats. Peptides were administered i.p. to mice and intracerebroventricularly to rats, 10 min before administration of the convulsant drug. CCK-8-SE and CCK-8-NS antagonized picrotoxin-induced seizures in both mice and rats, but had no effect on strychnine and pentetrazole-induced convulsions. In both species the octapeptide fragments which attenuated picrotoxin-induced seizures or prolonged the time until death contained the C-terminal tetrapeptide amide (CCK-5-8 [1947-37-1]) sequence of the mol. The C-terminal tripeptide (CCK-6-8 [5934-92-9]) and dipeptide (CCK-7-8 [5241-71-4]) had no anticonvulsive activity. The N-terminal nonsulfated tetrapeptide (CCK-1-4-NS [80790-40-5]) also slightly antagonized the effect of picrotoxin, but only in rats.

CCK26-33 degrading activity in brain and nonneural tissue: a metalloendopeptidase

CCK26-33 degrading activity in brain and nonneural tissue: a metalloendopeptidase. Steardo, L.; Knight, M.; Tamminga, C. A.; Barone, P.; Kask, A. M.; Chase, T. N. (Exp. Ther. Branch, Natl. Inst. Neurol. Commun. Disord. Stroke, Bethesda, MD 20205, USA). J. Neurochem., 45(3), 784-90 (English) 1985. CODEN: JONRA9. ISSN: 0022-3042. DOCUMENT TYPE: Journal CA Section: 2 (Mammalian Hormones) Section cross-reference(s): 7 Cholecystokinin octapeptide (CCK26-33) [25126-32-3] is metabolized by neural membranes with an initial cleavage to CCK29-33 [18917-24-3] and subsequent breakdown to CCK31-33 [5934-92-9] and CCK32-33 [5241-71-4]; this pattern of proteolysis occurs on incubation with either P2 or purified lysed synaptosomal membranes. The proteolysis of cholecystokinin by synaptic membranes of various rat brain areas and cellular membranes of peripheral tissue was examd. The pattern of degrdn. in brain did not differ among the regions studied. The overall proteolysis rate, as measured by the formation of tryptophan, was higher in the striatum than in the cortex, although CCK29-33 was formed at the same rate in both areas. In nonneural tissue, the rate of degrdn. was highest in liver membranes and lowest in pancreatic acinar cell prepns. The pattern of product formation is the same in peripheral compared with central nervous system membranes; thus, the degradative pathway does not appear to be unique to brain tissue. The enzyme present in synaptic membranes that is responsible for CCK29-33 formation requires a metal ion and sulfhydryl groups for the catalysis and thus is a metalloendopeptidase [80498-19-7]. Furthermore, its activity is inhibited by Ac-Gly-Phe-Nle-al [98448-61-4], a peptide aldehyde whose sequence bears some homol. to the amino acid sequence in the region of CCK26-33 that is cleaved by this enzyme.