HYPOKALEMIA DECREASES TESTOSTERONE PRODUCTION IN MALE-MICE BY ALTERING LUTEINIZING-HORMONE SECRETION

Potassium deficiency produced by feeding mice a low potassium diet cau sed a marked decrease in plasma and testicular testosterone concentrat ions and a concomitant fall in the weight of seminal vesicles and in r enal ornithine decarboxylase activity. All of these parameters were ra pidly restored when potassium supply was normalized. Immunocytochemica l analysis of gonadotropes and plasma LH values suggested that the pul satile liberation of LH by the pituitary was impaired in the potassium -deficient male mice. Because the synthesis of testosterone in the pot assium-deficient mice was stimulated by exogenous LH, hCG, or GnRH, on e can conclude that alteration of the transcellular potassium gradient could affect the regulation of the hypothalamo-hypophyseal-testicular axis by affecting the pulsatile release of GnRH. Our results showing that the stimulation of LH secretion after castration was similar in c ontrol and potassium-deficient male mice suggest that a testicular fac tor(s) different from testosterone could be implicated in the abnormal regulation of LH secretion in potassium-deficient mice. We conclude t hat plasma potassium concentration is an important factor in the regul ation of gonadotropin secretion and testicular functions.