EFFECTS OF FACTORS INHIBITING TENSION DEVELOPMENT ON OXYGEN CONSUMPTION OF GUINEA PIG TAENIA COLI IN HIGH K MEDIUM

Hypertonically added high-potassium induced a tension development in the guinea pig taenia coli, which was composed of two distinct parts, a phasic response and a tonic one (1, 2). The tonic response was dependent on the aerobic breakdown of carbohydrate and was abolished by substrate removal, anoxia, a decrease in temperature, 2, 4-dinitrophenol (DNP), lithium substitution and ouabain. These factors had little or no effect on the phasic response. From these data it was suggested that the phasic response is a passive process, whereas the tonic response is an active one depending on metabolism. A part of this concept is supported by the finding that the application of high K caused an increase in oxygen consumption that accompanies the muscle tension change (3). In the present paper, effects of factors inhibiting tension development, viz. glucose removal, low oxygen, decrease in temperature, DNP and ouabain, on oxygen consumption in high-potassium medium were studied. © 1969, The Japanese Pharmacological Society. All rights reserved.