Premium
KININS STIMULATE NET CHLORIDE SECRETION BY THE RAT COLON
Author(s) -
CUTHBERT ALAN W.,
MARGOLIUS HARRY S.
Publication year - 1982
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1982.tb09178.x
Subject(s) - kinin , endocrinology , chemistry , medicine , kallidin , bradykinin , chloride , secretion , transepithelial potential difference , amiloride , ion transporter , sodium , biochemistry , biology , receptor , membrane , organic chemistry
1 Short circuit current (SCC), transepithelial conductance and ion fluxes were measured across the isolated descending colon of the rat in response to bradykinin or kallidin. 2 Kinins added to the serosal bath caused immediate increases in SCC but were ineffective when added to the mucosal bath. Increases in SCC were accompanied by significant increases in transepithelial conductance. Threshold kinin concentration was 0.5 n m and maximal increases were seen at 50–100 n m . 3 A rat glandular kallikrein (7 n m ) or mellitin (2 μ m ) also increased SCC if added to the serosal bath. 4 Responses to kinins were unaffected by mucosal amiloride (100 μ m ) but attenuated or blocked by serosal frusemide (100 μ m ), indomethacin (1 μ m ) or mepacrine (50 μ m ). 5 Replacement of chloride ion in the serosal bath by gluconate and sulphate ions abolished responses to kinins which reappeared after chloride re‐addition. 6 Measurement of 36 Cl, 22 Na and 86 Rb fluxes across the tissue showed that the kinin‐induced increase in SCC resulted principally from increased net chloride secretion. Effects upon 22 Na or 86 Rb flux were minimal and made no contribution to the current responses observed in this tissue. 7 The results prove that kinins stimulate net chloride secretion in the rat colon, most probably via a prostaglandin‐dependent pathway.