THE DISTRIBUTION AND TURNOVER OF CORTISOL IN SHEEP

Abstract

SUMMARY When labelled cortisol was injected intravenously into sheep it disappeared rapidly from blood. A few minutes after injection the specific activity of plasma cortisol decreased in a simple exponential manner, and it was therefore assumed that cortisol was contained in one pool. Cortisol pool sizes and turnover rates were calculated from plasma cortisol specific activity and its rate of change. The estimates of turnover rates so calculated are higher than the rates of cortisol secretion reported by other workers. Because the turnover of cortisol in sheep is rapid it is possible that the assumption that cortisol is contained in one pool might give erroneously high values for the cortisol turnover rate.