STUDIES OF THE EFFECT OF BENDROFLUMETHIAZIDE ON SODIUM TRANSPORT AND METABOLISM IN THE TOAD BLADDER’

MCDOUGAL, BARBARA AND LAWRENCE P. SULLIVAN: Studies of the effect of bendroflume-thiazide on sodium transport and metabolism in the toad bladder. J. Pharmaco!. Exp. Ther. 172: 203-210, 1970. The effect of bendroflumethiazide (BHFT) on the metabolic processes supporting transepithe!ial Na transport in the isolated toad bladder has been studied. The thiazide inhibited short-circuit current (5CC) in bladders depleted of endogenous gly-cogen, inhibited stimulation of SOC by glucose and pyruvate and inhibited SOC supported solely by anaerobic metabolism. The drug does not interfere with glycolysis since it in-creases lactate accumulation. BHFT, however, did depress O consumption. The effect on lactate accumulation and O consumption also occurred in the absence of Na indicating that the drug has a direct effect on metabolism and may not directly affect the Na transport mechanism. Ouabain, which depresses lactate accumulation and inhibits Na-K-activated adenosine triphosphatase, caused the same fractional inhibition of SOC in bladders pretreated with BHFT as in control bladders indicating that the effects of these two inhibitors are quite different. The effects of BHFT and fluoroacetate, an inhibitor o