Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9034572 | Toxicology | 2005 | 10 Pages |
Abstract
Ursodeoxycholic acid (UDCA) has been widely used for treating cholestatic liver diseases. However, in a recent review of clinical trial articles, its therapeutic benefits were not proven. Therefore, we investigated whether UDCA prevents or potentiates glycochenodeoxycholic acid (GCDCA)-induced apoptosis in isolated rat hepatocytes. Hepatocellular cytotoxicity was assessed by lactate dehydrogenase (LDH) release, and apoptosis evaluated by DNA fragmentation, caspase activities, release of cytochrome C from mitochondria, and mitochondrial membrane potential change (ÎÏ). When hepatocytes were co-incubated with GCDCA and UDCA for a short time (2-6Â h), GCDCA-induced LDH release was significantly reduced, while prolonged co-incubation (12-20Â h) increased it. Similarly, the same co-incubation for a short time resulted in the inhibition of caspase activities and cytochrome C release, while prolonged incubation enhanced them compared with the incubation with GCDCA alone. Furthermore, UDCA significantly promoted the GCDCA-induced ÎÏ decline after 4Â h of incubation. These results demonstrated that UDCA reduced GCDCA-induced apoptosis in short incubation, but potentiated it in prolonged incubation. Based on these, we propose a hypothesis that induction of ÎÏ decrease from earlier stage of incubation may be responsible for the aggravation of GCDCA-induced apoptosis in long-term exposure, and would like to raise caution about clinical long-term use of UDCA.
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Authors
Shinichi Utanohara, Mayumi Tsuji, Shusuke Momma, Yuri Morio, Katsuji Oguchi,