[Studies on correlation between liver drug metabolizing enzyme activities and microsomal membrane fluidity in...

By the use of ANS(1-anilinonaphthalene-8-sulfonate) and DPH(1, 6-diphenyl-1, 3, 5-hexatriene) as fluorescent probes, correlation between liver microsomal membrane fluidity and drug metabolizing enzyme activity has been studied in rats. phenobarbital(PB) ip treatment caused an increase in P-450 content, cytochrome C reductase.aminopyrine N-demethylase(AMD) and glutathione S-transferase(GST) activities by 78, 66, 270 and 52%, respectively. However, there was a simultaneous decrease in microsomal membrane fluorescent intensity and microviscosity, i.e. an increase in membrane fluidity. There is a positive linear correlation between microsomal membrane fluidity and cytochrome C reductase and AMD activities (r = 0.798, r = 0.781, respectively, P less than 0.05). This result suggests that there may be some relationship between microsomal membrane fluidity and drug-metabolizing enzymatic activities in PB-treated rats.