Effect of ZVAD-fmk on hepatocyte apoptosis after bile duct ligation in rat.
OBJECTIVE
Retention and accumulation of toxic hydrophobic bile salts within hepatocyte may cause hepatocyte toxicity by inducing apoptosis. Apoptosis is a pathway of cell death orchestrated by a family of proteases called caspases. Z-Val-Ala-Asp (OMe)-fluoromethyl ketone (ZVAD-fmk) is a cell-permeable irreversible inhibitor of caspase. The purpose of this study was to evaluate the possible effect of ZVAD-fmk on hepatocyte apoptosis after bile duct ligation in the rat.


METHODS
Male Sprague-Dawley rats, weighing 250-300 g, were randomized to five groups of five rats each. Group 1 underwent common bile duct ligation and simultaneous treatment with ZVAD-fmk (dissolved in dimethylsulfoxide (DMSO)). Group 2 underwent common bile duct ligation and simultaneous treatment with Z-Phe-Ala-fluoromethyl ketone ( ZFA-fmk, dissolved in DMSO). Group 3 underwent sham operation and simultaneous treatment with the same amount of DMSO. Group 4 underwent sham operation and simultaneous treatment with the same amount of normal saline. Group 5 underwent common bile duct ligation without other manipulation. After three days, liver tissue was harv-ested for histopathologic analysis and measurements of apoptosis.


RESULTS
When compared with sham operation, common bile duct ligation significantly increased hepatocyte apoptosis (P = 0.008) and ductular proliferation (P = 0.007). ZVAD-fmk significantly diminished the increased hepatocyte apoptosis and ductular proliferation after common bile duct ligation (P = 0.008 and P = 0.007, respectively). ZFA did not show the same effects.


CONCLUSIONS
Hepatocyte apoptosis and ductular proliferation significantly increased after common bile duct ligation. ZVAD-fmk effectively diminished the increased hepatocyte apoptosis and ductular proliferation after common bile duct ligation, whereas ZFA-fmk did not.
Sheen-Chen
Shyr-Ming
SM
Department of Surgery, Chang Gung Memorial Hospital, Kaohsiung, 123 Ta-Pei Road, Niao-Sung Hsiang, Kaohsiung Hsien, Taiwan, China. smsheen@yahoo.com
Ho
Hsin-Tsung
HT
Chen
Wei-Jen
WJ
Eng
Hock-Liew
HL
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001651:Cholestasis, Extrahepatic / Q000188:drug therapy* / Q000473:pathology; D003135:Common Bile Duct / Q000473:pathology; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology*; D022781:Hepatocytes / Q000473:pathology*; D020287:In Situ Nick-End Labeling; D008026:Ligation; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
D000590:Amino Acid Chloromethyl Ketones; D015853:Cysteine Proteinase Inhibitors; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone