Adrenal steroid biosynthesis by different species of mouselike rodents

Abstract

Adrenals from voles ( Microtus agrestis), deer mice ( Peromyscus californicus and Peromyscus erimicus) and albino mice ( Mus musculus) incubated in Krebs-Ringer bicarbonate medium formed corticosterone as major endogenous end product in vitro and no cortisol was detected. These rodents belong to the superfamily Muroidea. Adrenals from pocket mice ( Perognathus baileyi and Perognathus penicillatus pricei), of the superfamily Geomyoidea, formed cortisol as a major end product from endogenous sources and no corticosterone or only traces, and the total output of ultraviolet-absorbing steroids by these glands in the presence of ACTH was much lower than that obtained with the adrenals of the Muroidea. The adrenals from Perognathus baileyi also formed cortisol as a major end product from radioactive substrates, but not corticosterone, while the predominant conversion product obtained with vole and albino mouse adrenals was corticosterone, and cortisol was either not found or present in minimal amounts. Cortisol was, further, not recovered when adrenals from 2- to 3-week-old male albino mice were incubated in plasma. Evidence for the endogenous formation of aldosterone and 18-hydroxycorticosterone was obtained in all the species, and the identity of these compounds was established when they were present as radioactive conversion products. The adrenals of Perognathus baileyi converted radioactive progesterone to aldosterone in amounts equaling the conversion to cortisol.