Immunocytochemical investigation of ACTH-cells and vasopressin in the pituitaries of humans died from myocardial infarction.

The pituitaries and adrenals of 30 patients died from extensive fresh myocardial infarction and of 25 patients died from other diseases were studied. In myocardial infarction the mean weight of the above glands was significantly higher than in other diseases. In most cases an increase in number of pituitary ACTH-cells was observed with the immunoperoxidase method. In non-cardiogenic shock (another 9 cases) gland weight was also increased but without a significant increase in the number of ACTH-cells. Hyperactivity of the anterior pituitary-adrenal system is due to a number of known factors. It may be assumed that patients who have infarction are either exposed to an extraordinary amount of stress stimuli or are more susceptible to stress than normal subjects. The findings may indicate the morphological basis of this situation. Of the shock phenomena, incomplete necrosis and haemorrhage of the adrenal cortex are frequent. In the pituitary neural lobe the neurosecretory material, which proved to be vasopressin with the PAP-method, was found to be increased more frequently in myocardial infarction than after other diseases.