title: Osmoregulation of arginine-8-vasopressin secretion in primary hypothyroidism and in Addison's disease.
abstract: The osmoregulation of arginine-8-vasopressin (AVP) was investigated in 14 patients with primary hypothyroidism and in 6 with Addison's disease. Plasma AVP was measured by radioimmunoassay. Patients with primary hypothyroidism were classified into subgroups with elevated (6.81 +/- 1.12 pmol/l) or normal (3.92 +/- 0.96 pmol/l) basal levels of plasma AVP. Following the infusion of 2.5% saline, a positive correlation was established between plasma AVP and plasma osmolality. A decreased osmotic threshold was found in hypothyroid patients with augmented basal AVP levels (pAVP = 0.37 (pOs-265), r = 0.71, P less than 0.01) as compared with that in hypothyroid patients with a normal AVP level (pAVP = 0.42 (pOs-280), r = 0.93, P less than 0.001). A relationship was demonstrated between the alteration in the AVP osmoregulation and the severity of the thyroid insufficiency. Patients with Addison's disease exhibited an increased basal level of plasma AVP (9.59 +/- 1.25 pmol/l) and a decreased osmotic threshold (pAVP = 0.42 (pOs-261), r = 0.63, P less than 0.01) contrasted to that of healthy volunteers (pAVP = 0.41 (pOs-280), r = 0.83, P less than 0.001). The osmoregulation disturbance of the AVP secretion may play a major role in the impaired water metabolism in primary hypothyroidism and in Addison's disease.
mesh_terms: D000224:Addison Disease / Q000097:blood / Q000503:physiopathology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D001127:Arginine Vasopressin / Q000097:blood / Q000378:metabolism*; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012462:Saline Solution, Hypertonic / Q000494:pharmacology; D012964:Sodium / Q000097:blood; D014882:Water-Electrolyte Balance / Q000187:drug effects
chemical_list: D012462:Saline Solution, Hypertonic; D001127:Arginine Vasopressin; D012964:Sodium