GONADOECTOMY REDUCED THE DEGREE OF DEVELOPMENT OF RENOVASCULAR HYPERTENSION IN FEMALE RATS CAUSED BY STOP OF HIGH-SALT DIET

Abstract

Objective: Excessive dietary salt intake is associated with an increased risk for hypertension. However, more research on measurement, storage and kinetics of sodium on blood pressure and sex hormones is required for dietary salt restrictions. The aim was to study the influence of gonadoectomy and stop of the high-salt diet on the development of renovascular hypertension (RVH) in female rats. Design and method: Was used the model of RVH 1 kidney 1 clip (1K1C) on female Wistar rats. All manipulations with animals were carried out according to the Council Directive 86/609/EEC principles. Gonadoectomized and normal rats of 8 weeks old (eight groups) were used. |There were two control groups: one with gonads © and one without (OvE). 4 groups out of remaining 6 groups of rats, had a high salt diet (4%). All rats from 6 groups the Goldblatt’s (1K1C) surgery was subjected. We had two groups with RVH with normal diet (0,25 % NaCl - RVH and OvE-RVH; two groups with high salt diet - RVH-HS and OvE-RVH-HS; and two groups with high salt diet, which was stop in two weeks after the Goldblatt’s (1K1C) surgery: RVH-ChHS and OvE-RVH-ChHS. In all animals the systemic blood pressure (mBP), diastolic (dBP), systolic (sBP) pressure, left ventricular pressure (LVP) and heart rate was directly measured. Left ventricular hypertrophy (LVH) was calculated as (LVweight)/(rat b.w.)*100%. Results: In all RVH groups, with and without gonads, the systemic arterial hypertension was developed. The most level of RVH was in RVH-ChHS rats: mBP - 145,7 ± 9,5 mmHg, dBP - 123,5 ± 10,4 mmHg, LVH - 0,214 ± 0,013 %. Ovariectomy leads to significant (p < 0,05) decrease in the degree of development of RVH. In OvE-RVH-ChHS was mBP 122,2 ± 6,3 mmHg, dBP 94,0 ± 6,0 mmHg and LVH 0,182 ± 0,009 %. Conclusions: Changing the diet from high salt to normal during the development of renovascular hypertension in female rats leads to an increase in the degree of disease. This effect was not observed in gonadoectomized female rats.