SEX DIFFERENCE IN THE ANTIDIURETIC ACTIVITY OF VASOPRESSIN IN THE RAT

Citation
Yx. Wang et al., SEX DIFFERENCE IN THE ANTIDIURETIC ACTIVITY OF VASOPRESSIN IN THE RAT, The American journal of physiology, 265(6), 1993, pp. 180001284-180001290
Citations number
32
Categorie Soggetti
Physiology
ISSN journal
00029513
Volume
265
Issue
6
Year of publication
1993
Part
2
Pages
180001284 - 180001290
Database
ISI
SICI code
0002-9513(1993)265:6<180001284:SDITAA>2.0.ZU;2-L
Abstract
A possible gender difference in the antidiuretic activity of vasopress in was studied in male and female Sprague-Dawley rats. Infusion of vas opressin (3-100 pg.kg-1.min-1) into conscious, chronically instrumente d water-loaded rats resulted in a dose-dependent antidiuresis in both male and female rats. Male rats, however, were more than three times m ore sensitive to vasopressin than female rats. Thus the effective dose s of vasopressin (pg.kg-1.min-1) to decrease urine flow to 30 mul.min- 1.100 g-1 (18 +/- 5 in males; 58 +/- 12 in females), to increase urine osmolality to 600 mosmol/kgH2O (35 +/- 5 in males; 119 +/- 15 in fema les), and to decrease free water clearance to 30 mul.min-1.100 g-1 (8 +/- 3 in males; 28 +/- 7 in females) were significantly (P < 0.05) low er in males. Furthermore, in vitro studies in papillary collecting duc t cells demonstrated a significantly higher density of vasopressin V2 receptors and a greater ability of vasopressin to stimulate adenosine 3',5'-cyclic monophosphate (cAMP) accumulation in males than in female s. Vasopressin V2-receptor density (maximum binding) was 359 +/- 47 an d 238 +/- 22 fmol/mg in male and female rats, respectively (P < 0.05). There was no difference in apparent dissociation constants (K(d)). Va sopressin resulted in a dose-dependent increase in cAMP accumulation i n papillary collecting duct cells, and at the highest concentration of vasopressin used (10(-8) M) cAMP increased from 44 +/- 10 to 182 +/- 51 fmol/mug protein in males and from 30 +/- 4 to 91 +/- 18 fmol/mug p rotein in females (P < 0.05). Thus in the present study we have demons trated at three levels a greater sensitivity of the antidiuretic activ ity of vasopressin in male vs. female rats. This difference may have i mportant physiological and pathophysiological consequences.