title: Kinin formation by catheptic enzyme in rat stomach.
abstract: Four uterine-contractile substances (a, b, c and d) were extracted from procedures with acetic acid, n-butanol, distilled water, and methanol from the reaction mixture obtained by incubating rat plasma kininogen with the kininforming enzyme in the rat stomach. Gradient and equilibrium chromatography on SP-Sephadex C-25 columns were carried out with the extract containing these materials (a, b, c and d). The materials could not be separated by chromatography on SP-Sephadex C-25, but were separated by high performance liquid chromatography (HPLC) with a Zorbax ODS reversed-phase column. All the materials (a, b, c and d) contracted the rat uterus and relaxed the rat duodenum. The uterine-contractile activity of the materials was abolished by chymotrypsin, but not by trypsin treatment. The retention times of materials a, c and d on HPLC were different from that of kallidin, MLBK, bradykinin (BK) and neurotensin; but the retention time of material b was equal to that of BK. The content ratio of a: b: c: d was 4: 4: 67: 25, calculated from the uterine-contractile activity of these materials. The apparent molecular weight of the major material c, estimated by gel chromatography, was 1650. Material c contracted the rat uterus (1.2 x 10(-10) g/ml), relaxed the rat duodenum (2 x 10(-10) g/ml), and produced a fall in rabbit blood pressure (4.4 x 10(-8) g/kg). Material c was classified as a biologically BK-like peptide which is distinct from kallidin, MLBK, BK and neurotensin.
mesh_terms: D000818:Animals; D002403:Cathepsins / Q000378:metabolism*; D002850:Chromatography, Gel; D002918:Chymotrypsin; D005260:Female; D005753:Gastric Mucosa / Q000201:enzymology*; D066298:In Vitro Techniques; D007704:Kininogens / Q000378:metabolism; D007705:Kinins / Q000096:biosynthesis* / Q000302:isolation & purification; D008970:Molecular Weight; D051381:Rats; D014357:Trypsin; D014590:Uterine Contraction
chemical_list: D007704:Kininogens; D007705:Kinins; D002403:Cathepsins; D002918:Chymotrypsin; D014357:Trypsin