IMPAIRED URINARY L-DOPA/DOPAMINE RATIO AS AN EARLY PREDICTOR OF RENAL DAMAGE IN FRUCTOSE OVERLOADED HYPERTENSIVE RATS.

PUYO AM; MARÍA CECILIA KRAVETZ; NATALIA L RUKAVINA MIKUSIC; NICOLÁS KOUYOUMDZIAN; LEE HJ; DEL MAURO J; MARCELA PANDOLFO; HOCHT C; SUSANA GORZALCZANIC; PEREDO HA; BELISARIO E. FERNÁNDEZ; MARCELO R. CHOI

Atenas

Congreso; Joint Meeting ESH-ISH Athens 2014; 2014

European Society of Hypertension

Fructose overload produces in the rat metabolic changes, insulin resistance, hypertension and kidney damage. We hypothesize that these changes are associated with alterations in the renal dopaminergic system contributing to sodium retention and hypertension, preceding urinary microalbuminuria, then changes in the renal production of dopamine (DA) were evaluated through the urinary L-DOPA/DA ratio and its relationship with the evolution of natriuresis, systolic blood pressure (SBP) and microalbuminuria in male Sprague Dawley rats. The groups studied were: a) Control (C, tap water to drink) and b) Fructose overloaded: (F, 10% w/v of fructose to drink), treated during 4 (C4,F4), 8 (C8,F8) and 12 (C12,F12) weeks, respectively (n=8 rats per group and per period). L-DOPA and DA were determined by HPLC; diuresis, sodium and creatinine were measured in 24 hr. urine samples; and creatinine, triglycerides, glucose and insulin in plasma. SBP was determined by tail-cuff. Fructose overload increased SBP (mmHg, C4: 121±8 vs F4: 145±1*; C8: 130±4 vs F8: 161±10#; C12: 133±5 vs F12: 163±4#), triglyceridemia (mg/dl, C8: 44±8 vs. F8: 116±10#; C12: 57±20 vs. F12: 143±18#), insulinemia (ng/ml, C8: 1.18±0.13 vs. F8: 3.05±0.75*; C12: 1.03±0.18 vs. F12: 1.9±0.31*), L-DOPA/DA ratio (C4: 0.49±0.05 vs F4: 1.9±0.09#; C8: 0.53±0.06 vs F8: 2.35±0.1#; C12: 0.54±0.07 vs F12: 2.57±0.2#), urine output (ml/24 hrs, C4: 11.79±1.42 vs F4: 24.54±2.05#; C8: 9.98±1.01 vs F8: 23.52±1.9#; C12: 11.55±1.6 vs F12: 28.37±2.07#), glycemia (mg/dl, C8: 144±12 vs. F8: 175±11*; C12: 135±6 vs. F12: 157±15) and decreased urinary sodium excretion (mEq/24 hr, C4: 1.01±0.05 vs F4: 0.83±0.04*; C8: 1.02±0.08 vs F8: 0.72±0.05#; C12: 1.04±0.08 vs F12: 0.64±0.04#) *p