Avaliação histomorfométrica do rim após isquemia quente e o efeito protetor do resveratrol ou da quercetina em ratos Wistar

Abstract

Introduction and Objectives: Injury caused by ischemia/reperfusion in the kidney remains a critical issue regarding nephron sparing surgery. There are still no quantitative results of the use of resveratrol and quercetin after renal ischemia. The objectives of this study are to quantitatively assess the histomorphology of the renal cortex after warm ischemia and the possible protective effect of resveratrol or quercetin. Methods: Sixty male Wistar rats (9 weeks of age) were divided into 6 groups of 10 animals: Sham (S); Sham treated with Resveratrol (SR) and Sham treated with Quercetin (SQ), Untreated Ischemia (I); Ischemia treated with Resveratrol (IR) and Ischemia treated with Quercetin (IQ). SR and IR groups received 30 mg/kg of resveratrol intraperitoneally 60 minutes before the surgical procedure. The SQ and IQ groups received 50 mg/kg of quercetin administered by gavage for 3 days before and after laparotomy, and intraperitoneally 60 minutes before surgery. The Ischemia group had the left renal artery and vein clamped for 60 minutes. The animals were euthanized 4 weeks after the procedure, blood was collected for serum urea and creatinine, and the kidneys were collected and fixed. Renal weight and volume, the cortex-non-cortex areas ratio (C-NC), the glomerular volume density (Vv[Glom]), the weighted mean glomerular volume (VWGV), and glomerular number per kidney (N[Glom]) were evaluated by stereological methods. The results were compared by one-way ANOVA with Bonferroni post-test, and considered significant when the value of p<0.05. Results: Serum urea in subgroup I was increased in relation to group S in 10.4%, and no significant differences were observed in the groups IR or IQ when compared to groups S and SR or S and SQ (p=0.01). The C-NC of the IQ group was higher than the I group in 5.9%, and the group I was significantly lower in relation to the S and SQ groups, which was also observed in relation to the SR group (p<0.01). The Vv[Glom] of the IR group was higher in 49.1% when compared to the group I and did not present significant difference when compared to the S and SR groups, whereas the IQ group had this parameter higher in 33.7% when compared to the group I, which decreased significantly when compared to S and SQ groups (p<0.01). The N[Glom] of the IR group was increased by 35.6% when compared to group I and did not present significant differences when compared to the S and SR groups (p=0.01), and the IQ was higher in 28.3% when compared to group I, which decreased in relation to the S and SQ groups (p<0.01). Renal weight and volume and VWGV showed no significant difference among groups. Conclusions: Arteriovenous warm renal ischemia promotes a great damage to the functional tissue of the kidney and previous administration of resveratrol or quercetin has protective effects on the renal cortex, suggesting that these compounds can be used preventively in partial nephrectomy.