Glomerular profile numerical density per area and mean glomerular volume in rats submitted to nitric oxide synthase blockade.

Rats submitted to chronic inhibition of nitric oxide synthase (NOS) have developed systemic hypertension and consequent renal injury. The present study aims to determine glomerular quantitative changes due to NOS inhibition in rats. Adults and normotensive Wistar rats were separated into control and L-NAME groups (each group n=10). The animals received water and food ad libitum, while L-NAME rats received NG-Nitro-L-Arginine methyl Ester hydrochloride to inhibit NOS (50mg/kg/day) in drinking water during 40 days. After that period the rats were sacrificed, the kidneys were removed, measured, and prepared for histological and stereological analyses. The glomerular density per area [NA(glom)] and the mean glomerular volume [v] were determined per animal in 15 random fields. In L-NAME rat the blood pressure was 76% higher than the respective control group with the same age. Glomeruli had global or segmental glomerular sclerosis; some glomeruli only presented an atrophic structure. The renal volume was not different between control and L-NAME rats (p>0.05). However, L-NAME rats had the NA(glom) 33% smaller than the control rats (p=0.0001) and, concomitantly, L-NAME rats had the v (glom) 33% higher than the control ones (p=0.004). These results demonstrate morphological renal alterations caused by NOS inhibition and hypertension.