?Renal Dopaminergic System dysfunction and its association with arterial hypertension and Na+, K+- ATPase overexpression in an experimental model of metabolic syndrome induced by fructose overload?

NATALIA L RUKAVINA MIKUSIC; KOUYOUMDZIAN, N.M.; MARÍA CECILIA KRAVETZ; DEL MAURO J; LEE HJ; PUYO AM; JORGE E TOBLLI; BELISARIO E. FERNÁNDEZ; CHOI, M.R.

Congreso; III International Congress in Translational Medicine Facultad de Farmacia y Bioquímica,; 2016

Introduction: Renal dopaminergic system (RDS) is a local natriuretic system that regulates renal function and blood pressure levels through inhibition of sodium transporters at tubular level, being the most important the enzyme Na+, K+- ATPase (NKA). A high fructose diet induces metabolic and hemodynamic changes that could be associated with an impairment of the RDS, leading to sodium retention, arterial hypertension and renal dysfunction. Aim: The aim of the study was to evaluate RDS state and its association with the development of hypertension, overexpression and activity of renal NKA and the presence of glomerular damage markers (nephrin and microalbuminuria) in fructose overloaded (FO) rats. Methods: Male Sprague Dawley rats were assigned to Control (C, tap water) or FO (10% w/v of fructose solution) groups, during 4, 8 and 12 weeks (n=8/group/period). Systolic blood pressure (SBP), metabolic parameters, and urinary L-dopa and dopamine (DA), creatinine, sodium and albumin were measured. 24-hour diuresis and urinary sodium excretion were determined. NKA activity was assessed by Fiske-Subarrow method and its expression was measured by western blot and immunofluorescence. Western blot analysis of renal expression of D1 receptor (D1R) and nephrin was also performed. Results: FO increased SBP (mmHg, C4: 121±8 vs. F4: 145±1*; C8: 130±4 vs. F8: 161±10#; C12: 133±5 vs. F12: 163±4#), which positively correlated (R2=0.78; p