Circulating levels of 17-hydroxycorticosteroid in prolonged hypothermia

¹ Clinical Physiology Laboratories, Institute of Clinical Investigation, University of Tennessee College of Medicine, Memphis, Tennessee

Thirty nonsurgically stressed dogs, anesthetized with pentobarbital sodium, were subjected to hypothermia induced by surface cooling. Plasma volumes, plasma 17-hydroxycorticosteroid concentrations and circulating amounts of corticoid were measured at rectal temperatures of 33°, 30°, 28°, 25° and, after 2 and 4 hours, at 25°C. No significant differences were encountered with respect to the plasma concentration of 17-hydroxycorticoid. Plasma volumes were significantly reduced in every instance. Adrenal cortical responsiveness was tested with exogenous ACTH in four dogs. It is concluded that hypothermia in the pentobarbitalized dog does not evoke adrenal cortical response as measured by peripheral arterial blood levels of 17-hydroxycorticosteroids.