Renal histology and immunohistochemistry after acute hemorrhage in rats under sevoflurane and ketoprofen effect

Clinical and anatomopathological study of urolithiasis in feedlot lambs subjected to diets with different phosphorus concentrations

Abstract Obstructive urolithiasis is common in farmed sheep and has a multifactorial etiology, but inadequate nutritional management is considered the most relevant condition for its occurrence. The objectives of this study were to verify the influence of two diets with different concentrations of calcium (Ca) and phosphorus (P) on the development of obstructive urolithiasis, and to describe the clinical and anatomopathological findings of the urinary system in sheep. Thirty male crossbred Santa Inês and Ile de France lambs were randomly distributed into two groups: Group 1 (G1, n = 15) - Ca: 1.9:1 P and 0.42% P; Group 2 (G2, n = 15) - Ca: P 1.5:1 and 0.65% P. The diets consisting of Coast-cross hay, soybean meal, wheat, and corn were provided for 90 consecutive days with water ad libitum. After the diagnosis of the disease, the lambs were subjected to clinical and surgical treatment, when necessary. Urolithiasis was detected in 36.7% (11/30) of lambs, 26.7% were asymptomatic and 10% (3/30) had urethral obstruction. A lamb was unobstructed after amputation of the urethral process and urethral catheterization, one died of bladder and uroperitoneum rupture, and another was sacrificed after the failure of perineal urethrostomy and cystostomy. The most frequent renal histopathological changes were vascular congestion, dilation, and tubular degeneration. Proteins in the tubular lumen were more pronounced in G2. The diets were rich in concentrate and had adequate Ca:P ratios, but caused calculogenesis, showing that excess minerals and a small amount of roughage can cause disease in the herd.

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.

Sevoflurane Induces DNA Damage Whereas Isoflurane Leads to Higher Antioxidative Status in Anesthetized Rats

Taking into account that there are controversial antioxidative effects of inhalational anesthetics isoflurane and sevoflurane and absence of comparison of genotoxicity of both anesthetics in animal model, the aim of this study was to compare DNA damage and antioxidant status in Wistar rats exposed to a single time to isoflurane or sevoflurane. The alkaline single-cell gel electrophoresis assay (comet assay) was performed in order to evaluate DNA damage in whole blood cells of control animals (unexposed; n = 6) and those exposed to 2% isoflurane (n = 6) or 4% sevoflurane (n = 6) for 120 min. Plasma antioxidant status was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. There was no statistically significant difference between isoflurane and sevoflurane groups regarding hemodynamic and temperature variables (P > 0.05). Sevoflurane significantly increased DNA damage compared to unexposed animals (P = 0.02). In addition, Wistar rats anesthetized with isoflurane showed higher antioxidative status (MTT) than control group (P = 0.019). There were no significant differences in DNA damage or antioxidant status between isoflurane and sevoflurane groups (P > 0.05). In conclusion, our findings suggest that, in contrast to sevoflurane exposure, isoflurane increases systemic antioxidative status, protecting cells from DNA damage in rats.