Effect of muscular exercise on adrenaline and noradrenaline secretion of the adrenal gland in the dog.

In 8 unanesthetized dogs, blood samples from the adrenal vein were collected by a modification of the method of Satake and his co-workers, and analyzed fluorimetrically for adrenaline and noradrenaline. Dogs paced by an attendant on a bicycle were run 2.0-13.1 km. Seven out of 8 dogs exhausted completely at the end of running. The adrenaline and noradrenaline secretion rates increas ed markedly in one dog, in which the body temperature rose after exercise above 42.0•Ž. The maximal secretion rate was observed in this case at 15 min after the end of running, and noradrenaline percentage to total catecholamines released from the adrenal gland at this peak time was 40 per cent. In 5 dogs only a slight increase and in the other 2 no increase in adrenal medullary secretion was observed after exercise.