[Interrelation between corticotropin and cortisol during static physical loading]

The time-course of changes in the blood corticotropin and cortisol concentration was studied in 9 dogs during standing with a load on the back. The pituitary-adrenocortical system was shown to be activated fairly rapidly. The initially occurring rise in corticotropin concentration was coupled with a more prolonged elevation of blood cortisol. In the absence of cortisol from the blood which was caused by long-term injection of chloditan, activation of corticotropic function proceeded more intensely whereas the reduction in corticotropin concentration after its initial increment was less demonstrable as compared to that seen in normal adrenal function.