Preparation and properties of microsomal membranes from isozonal cells of beef adrenal cortex.

Abstract

The purposes of this study were 1) to devise a method by which microsomal membranes could be prepared from homogeneous glomerulosa or fasciculata-reticularis cell populations from beef adrenals, and 2) to compare these zones with regard to C21-steroid 17α-hydroxylation of progesterone and 21-hydroxylation of progesterone and 17α-hydroxyprogesterone, cytochrome P45O, pH maxima and NADPH-cytochrome c reductase activity. Results of the study demonstrate that separation of tissues can be achieved by scraping the loosely adherent cortical cells away from the cells which adhere tightly to the capsule with a sharp scalpel. Microscopic examination revealed homogeneous glomerulosa and fasciculata cell populations. Microsomes prepared from cell populations separated in this way revealed the following: glomerulosa cell microsomes had virtually no C21 steroid 17α-hydroxylase activity while fasciculata cell micromes were active in both 17α- and 21-hydroxylation; the maximum activity in the pH range tested for 21-hydro...