Abstract 45: Sex Differences Of Renal11β-hsd1 And 11β-hsd2 Expression In A Doca-salt Model Of Hypertension.

Abstract

The balance between hydroxysteroid dehydrogenase 1 (11β-HSD1) and hydroxysteroid dehydrogenase 2 (11β-HSD2) have been implicated in the regulation of mineralocorticoid effects. We have previously shown in the DOCA-salt model of hypertension that males have a more pro-inflammatory immune profile and higher BP than females. The current study tested the hypothesis that males have a higher ratio of 11β -HSD1 to 11β -HSD2 and that preventing DOCA-salt induced increases in BP significantly shifts that ratio.At 10 wks of age, male and female Sprague-Dawley rats were anesthetized and a right uni-nephrectomy (UNX) was performed. After one week of recovery, rats were randomized to the following groups: 1) UNX controls, 2) DOCA-salt (200 mg) with 0.9% saline to drink, or 3) DOCA-salt with saline + hydrochlorothiazide (HCTZ; 55 mg/kg/day) and reserpine (RES; 4.5 mg/kg/day. After 3 weeks of treatment, the remaining kidney was isolated to measure mRNA expression of 11β-HSD1 and 11β-HSD2 via RT-qPCR.Control UNX males had a higher 11β-HSD1:11β-HSD2 ratio than females (0.9 ± 0.15 vs 0.3 ± 0.04; P=0.02). After DOCA-salt, 11β-HSD1 increased in both males and females (2.5 ± 0.1 vs. 1.3 ± 0.08; P treatment <0.0001). Males maintained a higher 11β-HSD1:11β-HSD2 ratio as well has had a higher increase in 11β-HSD1 to 11β-HSD2 ratio than females (P sex =0.04; P interaction =0.04) after DOCA-salt. With HCTZ/RES treatment, 11β-HSD1 to 11β-HSD2 ratios significantly decreased in both males and females (1.9 ± 0.5 vs. 0.8 ± 0.09; P treatment =0.002), but males maintained a higher 11β-HSD1:11β-HSD2 ratio vs females (P sex =0.002; P interaction =0.54). Our data suggests that there are sex differences in the balance of renal mRNA expression of 11β-HSD1 and 11β-HSD2, with males having a greater 11β-HSD1:11β-HSD2 ratio compared to females. Preventing DOCA-salt induced increases in BP significantly shifts this ratio through an upregulation of 11β-HSD2 in both sexes.