The Influence of the Adrenal Cortex on the Mobilization of Tissue Protein* By

For more than a decade the secretions of the adrenal cortex have been associated with the metabolism of protein. The work of Long and his collaborators clearly demonstrated that the administration of potent adrenal cortical extracts to experimental animals resulted in increased gluconeogenesis, associated with accentuated nitrogen excretion (l-3). This effect of the adrenal cortex on the catabolism of protein has been confirmed many times (4). There has accumulated, however, considerable evidence that variations in adrenal cortical secretion are not invariably accompanied by similar variations in protein catabolism (5-7). In fact, the reverse relationship has occasionally been demonstrated; e.g., increased protein breakdown after adrenalectomy (8), or decreased catabolism after pituitary-adrenal cortical activation (9, 10). These apparently anomalous observations can probably be resolved on the basis that the major function of the adrenal cortex in protein metabolism appears to involve the mobilization of protein stores in the body (11-15). The mobilization of carcass protein appears to require the intervention of the thyroid gland in addition to the adrenals (15). The present investigations substantiate the view that the mobilization of tissue proteins is an important function of the adrenal cortical hormones and suggest that the effects of these hormones on protein metabolism are produced primarily by labilization of the tissue proteins (16-18). In addition, the results reported below indicate that the end-result of the translocation of protein in the body due to pituitary-adrenal cortical activation may be local or systemic protein anabolism or catabolism, depending upon the tissue requirements for protein at the moment (17, 19).