Role of the paraventricular and ventromedial hypothalamic nuclear areas in the regulation of the pituitary-adrenocortical system

• Published in: Brain research Vol. 342; no. 1; p. 135
• Main Authors: Filaretov, A A, Filaretova, L P
• Format: Journal Article
• Language: English
• Published: Netherlands 02.09.1985
• Subjects: Adrenal Cortex Hormones - blood; Adrenal Cortex Hormones - physiology; Animals; Hydrocortisone - pharmacology; Hypothalamo-Hypophyseal System - physiology; Male; Paraventricular Hypothalamic Nucleus - physiology; Pituitary-Adrenal System - drug effects; Pituitary-Adrenal System - physiology; Rabbits; Stress, Physiological - physiopathology; Ventromedial Hypothalamic Nucleus - physiology
• ISSN: 0006-8993
• DOI: 10.1016/0006-8993(85)91361-7

The role of the paraventricular (PVN) and ventromedial (VMN) hypothalamic nuclei in the activation and inhibition of the pituitary-adrenocortical system was studied in chronic experiments on rabbits. The functioning of the pituitary-adrenocortical system was estimated by changes in blood corticosteroid levels. PVN and VMN lesions resulted in a reduction of the stress-induced corticosteroid rise. VMN lesions resulted in smaller changes of the stress-induced response than PVN lesions while combined VMN and PVN lesions did not cause a larger reduction of the stress-induced activation than lesions of either area. The data obtained confirm that the PVN and VMN are connected in series. Hydrocortisone (100 micrograms/kg) administered intravenously 5 min before immobilization inhibits the stress-induced corticosteroid rise in intact rabbits. PVN and VMN lesions result in a reduction of the hydrocortisone inhibitory effect, PVN lesions having a greater effect than VMN ones. The PVN is of greater importance in both the activation and the inhibition of the pituitary-adrenocortical system than the VMN.