The effect of ursodeoxycholic acid on glycochenodeoxycholic acid-induced apoptosis in rat hepatocytes.
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 (Deltapsi). When hepatocytes were co-incubated with GCDCA and UDCA for a short time (2-6 h), GCDCA-induced LDH release was significantly reduced, while prolonged co-incubation (12-20 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 Deltapsi decline after 4h 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 Deltapsi 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.
Utanohara
Shinichi
S
Department of Pharmacology, School of Medicine, Showa University, Hatanodai 1-5-8, Tokyo 142-8555, Japan.
Tsuji
Mayumi
M
Momma
Shusuke
S
Morio
Yuri
Y
Oguchi
Katsuji
K
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D020169:Caspases / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D045304:Cytochromes c / Q000378:metabolism; D053938:DNA Fragmentation / Q000187:drug effects; D004587:Electrophoresis, Agar Gel; D005999:Glycochenodeoxycholic Acid / Q000494:pharmacology*; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014580:Ursodeoxycholic Acid / Q000494:pharmacology*
D005999:Glycochenodeoxycholic Acid; D014580:Ursodeoxycholic Acid; D045304:Cytochromes c; D020169:Caspases