Adrenal Medullary Secretion in Tourniquet Shock

After tourniquet (4 hours) of the left femoral region of the dog, secretion rate of catecholamines in adrenal venous blood was studied by fluorometric method and the following conclusions were obtained. 1) Continuous tourniquet alone did not cause increase of adrenal medul-lary secretion. However, when the 4 hours' tourniquet was followed by reopening of blood circulation, secretion rate of adrenal medullary catechola-mines gradually increased and blood pressure decreased. Since increase of secretion of adrenal medullary catecholamines was not at all seen after splanchnicotomy, increase of secretion of adrenal medullary catecholamines derives from the adrenal medullary secretory nerve center. 2) When release of tourniquet was immediately followed by high pressure oxygen therapy with 3 ATA • O2 for 45 minutes, secretion of adrenal catecholamines did not increase nor did blood pressure decrease. The effect of high pressure oxygen therapy was examined in view of acid-base balance and this was considered due to the fact that advancement to acidosis was temporarily compensated by the decrease of PCO2 and by the increase of pH value, and occurrence of shock was restrained. Accordingly, acidosis may be one of the important factors for the occurrence of tourniquet shock.