Glibenclamide Effects on Renal Function and Histology after Acute Hemorrhage in Rats under Sevoflurane Anesthesia

Autophagy and Oxidative Balance Mediate the Effect of Carvedilol and Glibenclamide in a Rat Model of Renal Ischemia-Reperfusion Injury

BACKGROUND: Reactive oxygen species and cytokines are the main players in the development of renal ischemia-reperfusion (I/R) injury. AIM: The current study aimed to evaluate the effects of carvedilol and/or glibenclamide and the interaction between autophagy and oxidative stress. METHODS: 50 male rats were divided into five groups: Control, IR injury (IRI), carvedilol pretreated, glibenclamide pretreated, and combined carvedilol and glibenclamide pretreated. Measurements of renal blood flow (RBF), creatinine clearance, serum blood urea nitrogen (BUN), histopathological, and immunohistochemical evaluation of autophagy marker Becl-1 in the rat kidney were performed. Beclin-1and light chain 3 (LC3) Mrna expression was detected by real time polymerase chain reaction. RESULTS: IRI was associated with significant increases in BUN, tumor necrosis factor-alpha, nuclear factor κB, and histo (H) score value of Becl-1. However, there was a significant decrease in RBF, creatinine clearance, and glutathione peroxidase compared to the control group. There was significant increase in Beclin-1 and LC3 mRNA gene expression in carvedilol, glibenclamide, and combined treatment groups as compared to IRI and control groups. Combination of carvedilol and glibenclamide significantly restored IRI changes when compared with the other pretreated groups. CONCLUSION: This study suggests that carvedilol and glibenclamide are promising reno-protective drugs to reduce renal injury induced by I/R through their antioxidant and autophagy stimulation.

Nicorandil prevents the nephrotoxic effect of cyclosporine-A in albino rats through modulation of HIF-1α/VEGF/eNOS signaling

Despite that cyclosporine-A (CsA) is a widely used immunosuppressive drug, its nephrotoxic effect limits its long-term administration. Herein we tried to investigate its renal effect on endothelial dysfunction targeting the hypoxia-inducible factor (HIF-1α) / vascular endothelial growth factor (VEGF) / endothelial nitric oxide synthase (eNOS) pathway and the possible modulation by nicorandil. Eight groups of adult male Wistar rats were included: (1) control; (2) vehicle group (received oil); (3) glibenclamide 5 mg·kg-1·day-1 administered orally; (4) nicorandil 10 mg·kg-1·day-1 administered orally; (5) CsA 25 mg·kg-1·day-1 administered orally; (6) combined administration of CsA and nicorandil; (7) glibenclamide was added to CsA; and (8) both CsA and nicorandil were combined with glibenclamide. The treatment continued for six weeks. Combined nicorandil with CsA improved renal function deterioration initiated by CsA. CsA decreased the renal expression levels (P < 0.001) of HIF-1α, eNOS, and VEGF, inducing endothelial dysfunction and triggering inflammation, and upregulated the profibrotic marker transforming growth factor (TGF-β). Nicorandil fixed the disturbed HIF-1α/VEGF/eNOS signaling. Nicorandil corrected the renal functions, confirmed by the improved histological glomerular tuft retraction that was obvious in the CsA group, without significant influence by glibenclamide. Proper protection from CsA-induced nephrotoxicity was achieved by nicorandil. Nicorandil reversed the disturbed HIF-1α/VEGF/eNOS pathway created by CsA.

Effects of a Single Dose of Parecoxib on Inflammatory Response and Ischemic Tubular Injury Caused by Hemorrhagic Shock in Rats

Parecoxib, a selective COX-2 inhibitor, is used to improve analgesia in postoperative procedures. Here we evaluated whether pretreatment with a single dose of parecoxib affects the function, cell injury, and inflammatory response of the kidney of rats subjected to acute hemorrhage. Inflammatory response was determined according to serum and renal tissue cytokine levels (IL-1α, IL-1β, IL-6, IL-10, and TNF-α). Forty-four adult Wistar rats anesthetized with sevoflurane were randomized into four groups: placebo/no hemorrhage (Plc/NH); parecoxib/no hemorrhage (Pcx/NH); placebo/hemorrhage (Plc/H); and parecoxib/hemorrhage (Pcx/H). Pcx groups received a single dose of intravenous parecoxib while Plc groups received a single dose of placebo (isotonic saline). Animals in hemorrhage groups underwent bleeding of 30% of blood volume. Renal function and renal histology were then evaluated. Plc/H showed the highest serum levels of cytokines, suggesting that pretreatment with parecoxib reduced the inflammatory response in rats subjected to hemorrhage. No difference in tissue cytokine levels between groups was observed. Plc/H showed higher percentage of tubular dilation and degeneration, indicating that parecoxib inhibited tubular injury resulting from renal hypoperfusion. Our findings indicate that pretreatment with a single dose of parecoxib reduced the inflammatory response and tubular renal injury without altering renal function in rats undergoing acute hemorrhage.

Serum concentrations and renal expressions of IL-1 and TNF-a early after hemorrhage in rats under the effect of glibenclamide

PURPOSE

To investigate changes in the serum concentration and renal expression of IL-1 and TNF-α cytokines in rats that received sevoflurane and glibenclamide prior to hemorrhage.

METHODS

Two groups of sevoflurane-anesthetized Wistar rats (n=10): G1 (control) and G2 (glibenclamide, 1 µg/g i.v.); hemorrhage of 30% blood volume (10% every 10 min), with replacement using Ringer solution, 5 ml/kg/h. Serum concentrations of IL-1 and TNF-α were studied in the first hemorrhage (T1) and 50 min later (T2), renal expression, at T2.

RESULTS

In serum, G1 TNF-α (pg/mL) was T1=178.6±33.5, T2=509.2±118.8 (p<0.05); IL-1 (pg/mL) was T1=148.8±31.3, T2=322.6±115.4 (p<0.05); in G2, TNF-α was T1=486.2±83.6, T2=261.8±79.5 (p<0.05); IL-1 was T1=347.0±72.0, T2= 327.3±90.9 (p>0.05). The expression of TNF-α and IL-1 in the glomerular and tubular cells was significantly higher in the G2 group.

CONCLUSIONS

Hemorrhage and glibenclamide elevated TNF-α and IL-1 concentrations in serum and kidneys. High levels of TNF-α already present before the hemorrhage in the glibenclamide group may have attenuated the damages found in the kidneys after the ischemia event.