title: Vasopressin and A1 noradrenaline turnover during food or water deprivation in the rat.
abstract: In the present study, we have examined in Wistar rats the effects of food or water deprivation of 3 days on the hypophyso-adrenal axis, vasopressinergic system and activity of A1 noradrenergic brain stem cell group, which is involved in the control of the hypothalamic neuro-endocrine activity. Levels of adrenocorticotropic hormone (ACTH) and vasopressin (AVP) were determined by radio-immunoassay, and corticosterone level was determined by fluorimetric method. Plasma levels of ACTH and corticosterone were greatly increased in both groups of rats. In water-deprived rats, plasma AVP (13.83 +/- 1.63 vs. 3.03 +/- 0.23 pg/ml) and osmolality levels were significantly elevated with a marked decrease of AVP hypophysis content (272 +/- 65 vs. 1098 +/- 75 ng/mg protein), but not in food-deprived rats in which osmolality did not change and AVP remained stocked (2082 +/- 216 ng/mg protein) in the hypophysis without release in the plasma (1.11 +/- 0.23 pg/ml). These observations indicated that both food-deprivation and water-deprivation stimulated the pituitary adrenal axis thereby suggesting a stress state. AVP production is stimulated both by fluid and food restriction but is secreted with differential effects: during food restriction AVP secretion is limited to supporting the hypothalamic pituitary-adrenal system.
authors.affiliation: Département de Biologie, Faculté des Sciences, Tunis, Tunisia.
authors.forename: S
authors.initials: S
authors.lastname: El Fazaa
authors.forename: N
authors.initials: N
authors.lastname: Gharbi
authors.forename: A
authors.initials: A
authors.lastname: Kamoun
authors.forename: L
authors.initials: L
authors.lastname: Somody
mesh_terms: D000818:Animals; D003681:Dehydration / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D010913:Pituitary-Adrenal System / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D013217:Starvation / Q000378:metabolism*; D014667:Vasopressins / Q000378:metabolism*
chemical_list: D014667:Vasopressins; D009638:Norepinephrine