THE INFLUENCE OF GOSSYPOL ON THE POTASSIUM METABOLISM OF RATS AND THE EFFECT OF SOME POSSIBLE CONTRIBUTING FACTORS (LOW-K AND LOW-MG INTAKE)

Gossypol was shown to be a male antifertility agent with a fairly good prospect. Clinical trials indicated that the antifertility effect of gossypol was excellent, but occasional cases of hypokalemic paralysis might occur in the course of its administration. As to the part played by gossypoi in the development of such hypokalemia there are contradictory opinions. In isolated heart it has been noticed that gossypol Could deplete myocardial K, but in intact animals most authors believe that gossypol may have no effect on K metabolism.In the present work the effect of gossypol on the concentrations of some of the extracellular and intracellular ions, the level of exchangeable potassium, certain renal functions, and some other aspects of the K metabolism are observed in rats fed regular diet, low-K diet, and low-Mg diet. Results indicate:1. In low-K fed animals large dose of gossypol decreases the intracellular K and Mg ion concentrations in all the four skeletal muscles in consideration, while in regularly fed animals it only decreases the intracellular K ion concentration of a single muscle. It may thus be concluded that in rats gossypol may affect K metabolism, and that low-K intake may be a contributing factor in the gossypol-induced disturbance of K metabolism.2. In low-K fed animals small dose of gossypol decreases the intracellular Mg ion concentration in two of the skeletal muscles; although large dose of gossypol decreases the intracellular K and Mg ion concentrations in all the muscles, it does not alter the serum K ion concentration, and at the same time the renal concentrating, ability remains unimpaired. These facts suggest that the gossypol-indueed disturbance of K metabolism might be the result of a perturbed Mg metabolism.3. Large dose of gossypol may bring about atrophic changes of the skeletal muscles, as evidenced by a decrease of the body weight and the weight of the muscles, a lowering of the urinary creatinine coefficient, and a decrease of the level of exchangeable potassium per unit length of the. body.