Effects of paraventricular lesions on stimulated ACTH release and CRF in stalk-median eminence of the rat.
The effects of destroying the paraventricular nucleus (PVN) of the rat hypothalamus on pituitary-adrenal function were studied. Four days after PVN lesions were placed with a rotating knife, the basal plasma corticosterone level was normal, but the corticosterone response to electrical stimulation of the medial basal hypothalamus, surgical trauma, and ether-venesection stress was significantly inhibited. Four and 8 days after PVN lesioning and adrenalectomy, the basal plasma ACTH level was lower, and the rise of plasma ACTH level elicited by a 3-min ether inhalation was significantly smaller than in the adrenalectomized controls. Corticotropin-releasing factor (CRF) activity in the stalk-median eminence extracts from PVN-lesioned rats was significantly less than in the control extracts. The weight of the adrenals was decreased by both 2 and 4 wk after PVN destruction, and 2 wk after hemiadrenalectomy, the compensatory adrenal hypertrophy was inhibited. The plasma corticosterone response to ether-venesection stress was inhibited only temporarily because it returned to normal by the end of the 4th postoperative week. The results are consistent with the hypothesis that a substantial portion of CRF-containing fibers in the stalk-median eminence region either originate from or run though the PVN or its immediate vicinity.
D000311:Adrenal Glands / Q000033:anatomy & histology; D000324:Adrenocorticotropic Hormone / Q000097:blood / Q000378:metabolism*; D000818:Animals; D003345:Corticosterone / Q000097:blood; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism*; D007031:Hypothalamus / Q000502:physiology*; D008473:Median Eminence / Q000378:metabolism*; D009929:Organ Size; D010286:Paraventricular Hypothalamic Nucleus / Q000502:physiology* / Q000601:surgery; D010913:Pituitary-Adrenal System / Q000502:physiology*; D051381:Rats; D013312:Stress, Physiological / Q000503:physiopathology
D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D003345:Corticosterone