The major side effect of cyclosporin A is severe nephrotoxicity. It is likely that cyclosporin A causes vasoconstriction leading to hypoxia-reperfusion injury; therefore, these experiments were designed to attempt to obtain physical evidence for hypoxia and free radical production in kidney following cyclosporin A. Rats were treated daily with cyclosporin A (25 mg/kg ig) for 5 days, and pimonidazole, a hypoxia marker, was injected 2 h after the last dose of cyclosporin A. A dose of α-(4-pyridyl-1-oxide)- N- tert-butylnitrone (4-POBN) was injected 3 h after cyclosporin A to trap free radicals. Cyclosporin A doubled serum creatinine and decreased glomerular filtration rates by 65% as expected. Pimonidazole adduct binding in the kidney was increased nearly threefold by cyclosporin A, providing physical evidence for tissue hypoxia. Moreover, cyclosporin A increased 4-POBN/radical adducts nearly sixfold in the urine but did not alter levels in the serum. Glycine, which causes vasodilatation and prevents cyclosporin A toxicity, minimized hypoxia and blocked free radical production; however, it did not alter cyclosporin A blood levels. These results demonstrate for the first time that cyclosporin A causes hypoxia and increases production of a new free radical species exclusively in the kidney. Therefore, it is concluded that cyclosporin A causes renal injury by mechanisms involving hypoxia-reoxygenation, effects which can be prevented effectively by dietary glycine.

No abstract

It is known that women develop hepatic injury more rapidly and with exposure to less ethanol than men; however, mechanisms remain unclear. The purpose of this study was to determine if an enteral alcohol delivery model could be used to study susceptibility of females to alcohol-induced liver injury. Male and female Wistar rats (age- or weight-matched) were given ethanol (11-12 g.kg-1.day-1) continuously for up to 4 wk via intragastric feeding, and control rats received a high-fat diet without ethanol. There were no significant differences in body weight among the groups studied. Furthermore, mean ethanol concentrations, their cyclic pattern in urine, and rates of ethanol elimination were also not different between the genders under these conditions. Ethanol treatment elevated serum aspartate aminotransferase levels in male rats to 126 +/- 10 IU/l after 4 wk. In females, however, values increased more rapidly and reached significantly higher values at 4 wk (168 +/- 18 IU/l). Steatosis, inflammation, and necrosis assessed histologically also developed more rapidly and were more severe in females than males. Steatosis due to ethanol exposure, which was localized in centrilobular areas in males, was panlobular in the female. Moreover, endotoxin in plasma, intercellular adhesion molecule 1 expression in hepatic sinusoidal-lining cells, and the number of infiltrating inflammatory cells in the liver were 2-2.5-fold greater in females than males. These changes possibly account for increased hepatic injury due to ethanol in the female.

Coffee consumption after colectomy was safe and was associated with a reduced time to first bowel action.