Sinvastatina e lesão renal aguda isquêmica em ratos

Morphofunctional study on the effects of passive smoking in kidneys of rats

Objective

To analyze whether passive inhalation of cigarette smoke causes morphological, structural, and functional changes in kidneys of rats.

Methods

Wistar rats, aged eight weeks, weighing on average 260g, were divided into Control Group and Smoking Group. Each group was subdivided into four groups of ten animals for morphofunctional analysis, in a period of seven and 28 days. The Smoking Group was exposed to smoke of 40 cigarettes per day, at certain times and in automated equipment for cigarette burning, called smoking machine (SM-MC-01). After the exposure period, urine and blood samples were collected for the functional analyses, and the kidneys were dissected and submitted to histological procedures for morphoquantitative analyses.

Results

After exposure of animals of the Smoking Group, the following were observed: lower weight gain; lower water and feed intake; decreased renal weight, diameter, and volume; reduction in cortical thickness and glomerular volume density; decrease in glomerular and capsular diameter; increase in mesangial density; decreased urine volume; increased levels of glucose, serum creatinine and microalbuminuria; decreased urinary creatinine levels and creatinine clearance rate.

Conclusion

Passive smoking negatively influences renal morphology and glomerular filtration rate, with effects similar to those described in the literature regarding active smoking.

The impact of pretreatment with simvastatin on kidney tissue of rats with acute sepsis

It has been reported that changes in cytokine levels affect mitochondrial functions, levels of hypoxia-inducible factor α (HIF-1α), and tissue damage during sepsis. We aimed to investigate the effects of simvastatin pretreatment on mitochondrial enzyme activities, and on levels of ghrelin, HIF-1α, and thiobarbituric acid reactive substances (TBARS) in kidney tissue during sepsis. Rats were separated into four groups, namely, control, lipopolysaccharides (LPS) (20 mg/kg), simvastatin (20 mg/kg), and simvastatin + LPS. We measured the levels of mitochondrial enzyme activities and TBARS in the kidney using spectrophotometry. The histological structure of the kidney sections was examined after staining with hematoxylin and eosin. Tumor necrosis factor α (TNF-α), IL-10, HIF-1α, and ghrelin immunoreactivity were examined using proper antibodies. In tissue, TNF-α (p < 0.01) and HIF-1α (p < 0.05) levels were increased in the simvastatin + LPS and LPS groups. TBARS levels were higher in the LPS group than in the other groups (p < 0.01), but they were similar in the simvastatin + LPS and control groups (p > 0.05). Ghrelin immunoreactivity was lower in the LPS group (p < 0.05) and higher in the simvastatin + LPS group than in the LPS group (p < 0.01). We observed tubular damage in the sections of the LPS group. There were no differences in mitochondrial enzyme activities between the groups (p > 0.05). We observed that pretreatment of simvastatin caused favorable changes on ghrelin and TBARS levels in rats with sepsis.

Antioxidant protection of statins in acute kidney injury induced by sepsis

Objective Evaluating the effect of preconditioning with simvastatin in acute kidney injury induced by sepsis. Method Male adult Wistar rats were divided into the following groups: SHAM (control); SHAM+Statin (0.5 mg/kg simvastatin, orally); Sepsis (cecal puncture ligation – CPL); Sepsis+Statin. Physiological parameters, peritoneal fluid culture, renal function, oxidative metabolites, severity of acute kidney injury and animal survival were evaluated. Results The treatment with simvastatin in induced sepsis showed elevation of creatinine clearance with attenuation of generation of oxidative metabolites, lower severity of acute kidney injury and reduced mortality. Conclusion This investigation confirmed the renoprotection with antioxidant principle of the simvastatin in acute kidney injury induced by sepsis in an experimental model.