Adrenocortical response during corrected and uncorrected hypercapnic acidosis.

Abstract

Adrenal venous flow rate and cortisol synthesis have been measured in dogs subjected to hypercapnic acidosis before and after intravenous administration of 0.34 mm/kg of tris (hydroxymethyl) amino methane (THAM). A comparison was made of adrenal venous, peripheral venous, and arterial blood, pH, pCO2 and O2 saturation. During uncorrected hypercapnic acidosis the concentration of cortisol increased while adrenal venous flow rate decreased, but there was a significant increase in the minute output of cortisol. With the concomitant administration of 0.34 mM/kg THAM, adrenal venous flow rate doubled. However, since this enhanced flow rate was accompanied by a sharp reduction in cortisol secretion, the minute output of cortisol returned to control levels. The possibility of a direct effect of THAM on the adrenal vascular bed and synthetic processes is discussed. Throughout all the above experiments adrenal venous blood resembled arterial blood rather than peripheral blood in its pCO2, O2 saturation and pH.