Received December 6, 2005
Revised January 4, 2006
Accepted after revision February 27, 2006
Renal function in juvenile rats subjected to pre-natal malnutrition and chronic salt overload
João C. G. Magalhães 1,
Alex B. Silveira 1,
Diogenes L. Mota 1,
Ana D. O. Paixao 1*
1 Universidade Federal de Pernambuco
* To whom correspondence should be addressed. E-mail: adpaixao{at}ufpe.br.
 |
Abstract |
|---|
Dietary sodium may contribute to hypertension and cardiovascular and renal disease if a primary deficiency of the kidney to excrete sodium exists. In order to investigate whether chronic 1% NaCl drinking water changes blood pressure and renal hemodynamics in juvenile Wistar rats subjected to pre-natal malnutrition, an evaluation of plasma volume, oxidative stress in kidney, proteinuria and renal hemodynamics was carried out. Malnutrition was induced by a multideficient diet. Mean arterial pressure, renal blood flow and glomerular filtration rate (GFR) were measured through a blood pressure transducer, a flow probe and inulin clearance, respectively. Plasma volume and oxidative stress were measured by means of Evans blue method and by monitoring thiobarbituric acid reactive substances (TBARS) in the kidneys, respectively. Urinary protein was measured by precipitation with 3% sulfosalicylic acid. It was observed that pre-natal malnourished rats presented higher values of plasma volume (26%, p < 0.05), kidney TBARS (43%, p <0.1) and blood pressure (10%, p < 0.01) when compared with the control group. However, they showed no change in renal hemodynamics or proteinuria. Neither pre-natal malnourished nor control rats treated with sodium overload presented plasma volume or blood pressure different from their respective control groups, but both groups presented elevated proteinuria (p < 0.01). The pre-natal malnourished group treated with sodium overload presented higher values of kidney TBARS, GFR and filtration fraction (58%, 87%, 72%, respectively, p < 0.01) than its respective control group. In summary, sodium overload did not exacerbate the hypertension in juvenile pre-natal malnourished rats, but induced renal hemodynamic adjustments compatible with the development of renal disease.
Key Words:
Nutrition, Renal, Sodium
