Mechanism of restoration of ACTH release in rats with long-term lesions of the paraventricular nuclei
|Published in||Journal of Endocrinology. 1986, vol. 111, no. 1, p. 75-82|
|Abstract||The effects of lesions in the paraventricular nucleus (PVN) on the adrenocortical response to ether stress were investigated in neurohypophysectomized and intact rats. During the first 4 days after placement of lesions in the PVN, the corticosterone response to ether stress was almost completely inhibited. It then gradually increased and, within 4-6 weeks of surgery, was restored to about 60% of that in sham-operated rats. Basal plasma concentrations of corticosterone were low in rats after placement of lesions in the PVN and/or after neurointermediate lobectomy (NILX). Corticosterone responses to ether stress were similar in groups submitted to PVN lesions and/or NILX, and lower than those in the appropriate sham-operated groups. In all lesioned groups, plasma ACTH concentrations after a combination of stressors (ether plus laparotomy) were also lower than those in the sham-operated groups. Six weeks after lesioning of the PVN, immunoreactive rat corticotrophin-releasing factor-41 (rCRF-41) concentrations in stalk-median eminence (SME) extract fell to about 5% of that in sham-operated rats, while immunoreactive arginine vasopressin (AVP) concentrations did not change. Immunohistochemistry revealed a substantial decrease in rCRF-41 immunostaining of the median eminence 6 weeks after lesioning of the PVN, though randomly located clusters of stained terminals were still seen in the whole rostro-caudal extent of the median eminence. A mixture containing synthetic rCRF-41 and AVP, in proportions similar to those in SME extracts from sham-operated rats, caused significantly less release of ACTH from anterior pituitary cell cultures than did SME extracts from sham-operated rats.(ABSTRACT TRUNCATED AT 250 WORDS)|
|Keywords||Adrenal Cortex/secretion — Adrenocorticotropic Hormone/secretion — Animals — Arginine Vasopressin/metabolism — Corticosterone/secretion — Corticotropin-Releasing Hormone/metabolism — Male — Paraventricular Hypothalamic Nucleus/physiology — Rats — Rats, Inbred Strains — Stress, Physiological/physiopathology — Time Factors|
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|Research group||Progéniteurs neuronaux (141)|
|DOHANICS, J et al. Mechanism of restoration of ACTH release in rats with long-term lesions of the paraventricular nuclei. In: Journal of Endocrinology, 1986, vol. 111, n° 1, p. 75-82. doi: 10.1677/joe.0.1110075 https://archive-ouverte.unige.ch/unige:74768|