Perinatal taurine status influences the effect of high sugar on renal potassium excretion in adult conscious female rats

Abstract

High sugar intake can impair renal function before increasing blood pressure. The present study tests the hypothesis that perinatal taurine status influences the effect of high sugar intake on renal potassium excretion in adult conscious female rats. Female Sprague‐Dawley rats were fed normal rat chow and given water alone (C), water with 3% beta‐alanine (taurine depletion, TD) or water with 3% taurine (taurine supplementation, TS) from conception until weaning. Their female offspring were treated with 5% glucose in drinking water (CG, TDG or TSG) or water alone (CW, TDW or TSW) from weaning onward. At 7‐8 weeks of age, renal potassium excretion at rest and after an acute normal saline load (5% of body weight) was tested in conscious, restrained rats. Perinatal taurine depletion, supplementation and glucose treatment alone did not alter renal potassium excretion at rest or after saline load. High sugar intake significantly decreased potassium excretion at rest in TDG and TSG (CW 2.1±0.4 μEq/min/gKW, CG 1.3±0.3 μEq/min/gKW, TDG 1.0±0.3 μEq/min/gKW, TSG 1.0±0.2 μEq/min/gKW; P < 0.05), but only the TDG group displayed decreased response to saline load. Tubular potassium reabsorption increased in TDG as indicated by decreased fractional potassium excretion. Plasma potassium levels significantly decreased only at rest in TDG. Glomerular filtration rates significantly decreased only at rest in TSW. Although non‐fasting blood sugar was higher in all glucose treated animals, their fasting blood sugar and glucose tolerance were not significantly different. The present data indicate that perinatal taurine status especially depletion heightens the adverse effect of high sugar intake on potassium excretion in adult conscious female rats.