Open AccessTHE INHIBITORY EFFECT OF PAPAVERINE ON RESPIRATION-DEPENDENT CONTRACTURE OF GUINEA PIG TAENIA COLI IN HIGH-K MEDIUM. III. THE DIFFERENTIAL EFFECT OF PAPAVERINE AND ROTENONE ON DT DIAPHORASE
Author(s) -
Shuji Tsuda,
Norimoto Urakawa,
Jun-ichi Fukami
Publication year - 1977
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.27.855
Subject(s) - taenia coli , papaverine , rotenone , guinea pig , chemistry , biology , respiration , pharmacology , mitochondrion , biochemistry , anatomy , endocrinology
The differential effects of papaverine (Pap) and rotenone (Rot) were studied on the highly respiration-dependent contracture of guinea pig taenia coli in 40 mM potassium (40-K) medium, on isolated DT diaphorase activity and on mitochondrial respiration. The inhibition of guinea pig taenia coli to the 40-K induced tension by Rot (5 x 10(-7)M) was fully reversed by the addition of a water soluble vitamin K3 (VK3) derivative or menadione sodium bisulfite (MSB). A low concentration (10(-7)--10(-6)M) of Pap which had no effect on the 40-K induced tension inhibited the VK3 restored tension from the Rot suppression, corresponding to a Pap inhibition of the isolated DT diaphorase. Inhibition of the effective concentration of Pap to the 40-K induced tension development was never reversed by addition of VK3 or MSB. In taenia coli, both MSB and VK3 established a bypass of the Rot sensitive site on the mitochondrial respiratory chain by means of the DT diaphorase system. The difference in washout-efficacy between Pap and Rot on the inhibition of 40-K induced tension was ascribed to a difference in their mitochondrial binding properties.