Functional Morphology of the Neurohormonal System in Myocardial Infarction
It is known that the hormones of neurosecretory cells (ADH vasopressin) and adrenal cortex (gluco- and mineralocorticoids) have a direct influence on blood vessels and the myocardium. In the present research the morphologic state of the hypothalamohypophyseal neurosecretory system (HHNS) and the adrenal cortex (AC) of 80 men who died at different periods after the onset of myocardial infarction (1 day-1,5 months) were studied. In one-third of the cases, sodium and potassium in the blood (plasma and erythrocytes) were examined in the course of the disease. Our research shows that myocardial infarction is accompanied by strong activation of the HHNS and AC. It is displayed: (1) in a tendency to reduced noradrenaline content in the hypothalamus (biochemical research in 12 cases); (2) in a rise of neurosecretory activity (especially of the supraoptic nucleus, SON) shown by morphometric, morphologic, and histoenzymologic tests; and (3) in a hypertrophy of corticotropic cells, with an increase of histamine concentration in the gland (as judged by the number of mast cells in the adeno- and neurohypophysis). In the AC, an increase of synthetic and secretory function, with an increased activity of steroidogenic enzymes (3β-ol, NADP) and a predominance of dark cells with prominent cytoplasmic RNA, were observed. If myocardial infarction was complicated by decompensation (20 cases), a high activity of the HHNS was found, with multiple small vacuoles in the secretory cells of the SON. Their appearance clearly corresponded to the rise of Na+ and the fall of K+ in the erythrocytes. In the above cases one invariably saw a hypertrophy of the zona glomerulosa of the AC which produces aldosterone. No exhaustion of the neurohormonal system was observed in myocardial infarction.