Effects of isoflurane, pentobarbital, and urethane on apoptosis and apoptotic signal transduction in rat kidney

Background: Renal cell apoptosis contributes significantly to the pathogenesis of acute renal failure. Anesthetic agents have been shown to modulate apoptotic signal transduction in various tissues. We examined the effects of 6 h of different general anesthetic techniques on renal cell apoptosis in rat kidneys. Methods: Twenty-one male Sprague-Dawley rats were randomly allocated into four groups: (i) control, non-anesthetized rats (n = 3) and rats anesthetized with (ii) inhaled isoflurane (n = 6), (iii) intraperitoneal pentobarbital (n = 6), and (iv) intraperitoneal urethane (n = 6). Animals were sacrificed 6 h after the induction of anesthesia. Results: Apoptosis was assessed by terminal deoxynucleotidyl transferase-fluorescein end-labeling analysis. RNA was extracted from the left kidney to probe cDNA microarrays. Gene expression was measured as a percentage of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and subsequently confirmed using reverse transcriptase-polymerase chain reaction (RT-PCR). Compared with the control (no anesthesia), urethane significantly (P < 0.001) induced apoptosis in both the renal cortex and medulla. Isoflurane significantly (P < 0.001) inhibited apoptosis in the medulla. Microarray analysis revealed that urethane up-regulated more (74) genes than pentobarbital (16) and isoflurane (10). Isoflurane down-regulated more genes (85) than pentobarbital (74) and urethane (12). These anesthetic-induced modulations were significant (P < 0.05) for 60 isoflurane-, 30 pentobarbital- and 4 urethane-modulated genes. Conclusion: Our results suggest that general anesthetic drugs have an effect on renal cell apoptosis and apoptotic signal transduction, and thus may potentially affect the risk of subsequent acute renal failure.