[Characteristics of neurosecretory centers of the rat hypothalamus associated with the regulation of adrenal cortex function].

The reaction of neurosecretory cells of some hypothalamic centers of rats of different age to experimental change of the blood level of corticoids to elucidate their role in the regulation of function of the hypophyseoadrenocortical system was studied. Immunohistochemical methods revealed corticoliberin- and vasopressinergic cells in the hypothalamic paraventricular nucleus and vasopressinergic cells in the anterocommissural group of neurosecretory cells and in the supraoptic nucleus. The number of revealed corticoliberin-immunoreactive cells and the value of nucleoli of vasopressinergic cells served an indicator of the intensity of synthesis of neurohormones. In accordance with literature data there was an increase in the number of corticoliberin-immunoreactive cells after adrenalectomy. Vasopressinergic cells of the anterocommissural group were activated after true adrenalectomy. They responded by lowered activity to sham adrenalectomy. Small cell vasopressinergic elements of the paraventricular nucleus and, to a lesser degree, large cell elements responded by a rise of activity to true and sham adrenalectomy. It was assumed that vasopressinergic elements of the anterocommissural group were sensitive to the content of peripheral blood corticoids and were involved in the system of long negative feedback. Vasopressinergic elements, mostly small cells of the paraventricular nucleus, appeared to be responsible via the system of short negative feedback for maintaining the hypophyseal ACTH level.