Effects of Adrenalectomy and Resubstitution with Moderate and High Doses of Cortisone Acetate on Lipolysis and47Calcium Uptake in Rat Adipose Tissue In Vitro

Abstract

Calcium accumulation in epididymal fat tissue was studied in sham-operated, adrenalectomized and cortisone resubstituted rats. The accumulation was measured when lipolysis was stimulated by noradrenaline, dibutyryl cyclic AMP and theophylline. It was shown that the different corticoid states significantly altered the passive calcium uptake into the tissue. Glucocorticoid deficiency diminished and glucocorticoid excess increased calcium uptake. The lipolytic response was unchanged when calcium was present in the medium. With increasing calcium depletion, fat tissue from adrenalectomized rats showed less resistence to calcium deprivation with a consequent diminished lipolytic response which could be normalized by the readdition of calcium. Evidence is presented indicating that cortisone is required for an intact passive translocation of calcium across plasma membranes.