Time course expression data from Brown Norway rat livers treated with nevirapine or galactosamine or both

Nevirapine alone produces only mild hepatic hypertrophy in the rat. Single ip dose galactosamine produces transient hepatocellular apoptotic and oncotic cell death mimicking viral hepatitis with portal inflammatory infiltrate and biliary hypertrophy and hyperplasia. Damage is typically resolved within 7-10 days. However if rats are pretreated with nevirapine at specific doses for 7 days prior to the single galactosamine dose, bridging fibrosis is observed, 8 days after the single galactosamine dose is given. We used microarrays to detail the global programme of gene expression underlying the sequential responses of nevirapine alone, galactosamine alone, and the identified distinct classes of up-regulated genes during this process. 50 liver samples were analyzed. Liver samples were snap frozen in liquid nitrogen from rats dosed with nevirapine (150, 100,75 mg/kg) for 7 days before a single ip dose of galactosamine at 750 mg/kg and then euthanized eight days later (nevirapine group). Comparisons were made to rats dosed with nevirapine (75 mg/kg) only for 15 days (nevirapine group) and to rats dosed with a single ip galactosamine only dose (750 mg/kg) and euthanized after 8 days (galactosamine group). The purpose was to examine the 8 day period over which fibrosis occurred when the nevirapine and galactosamine co-administration produced fibrosis and the single drug dosages did not. Time points after galactosamine administration (3 hr, 24 hr, 48 hr and 8 days) were chosen for sampling.