Cholesterol Ester Concentration and Corticosterone Production in Adrenals of the C57BL/10 and DBA/2 Strains in Relation to Adrenal Lipid Depletion*

Abstract

During incubations in vitro for 2 hr in the presence of ACTH, adrenals of adult male C57BL/1OJ mice synthesized significantly more corticosterone from endogenous precursors than did adrenals of adult male DBA/2 J mice. Characteristically the amount of steroid produced by the latter strain fell during the second hour while that of the former continued to rise or remained constant. The concentration of cholesterol ester in the adrenal of the C57 was seven times as high as that of the DBA but unesterified cholesterol and triglyceride concentrations were the same in both. Histological studies with Sudan IV staining showed the adrenal cortex of the C57 to be lipidrich and that of the adult DBA to be lipid-poor. The adrenals of two strains known to carry the adrenal lipid depletion gene (ald) were shown to have cholesterol ester levels close to that of the DBA. There is a marked decline both in sudanophilia and in the cholesterol ester content of the adrenals at puberty in DBA mice but not in C57 mice. As in the known aid strains, prepubertal castration of male DBA mice prevented lipid depletion from occurring at puberty and castration of adult DBA males resulted in lipid repletion. The responses of the plasma corticosterone concentration to stress (saline injection) and to exogenous ACTH in these two strains are discussed in light of our previous findings concerning the characteristics of hepatic metabolism of the steroid. Although there is a clear correlation between high cholesterol ester concentration, capacity for production of corticosterone by the adrenal and high response of the plasma steroid to stress, it is suggested that a higher degree of stimulation of the C57 adrenal by endogenous ACTH must also contribute to the greater elevation of plasma corticosterone in this strain following stress. (Endocrinology90: 93, 1972)