Role of microsomal triglyceride transfer protein in induction of fatty liver in suncus

Abstract

It has previously been shown that fatty liver was easily induced in suncus by starvation and that it was easily reversed by refeeding. It was also previously reported that a defect in the assembling process of apolipoprotein (apo) B-containing lipoprotein (very low density lipoprotein, VLDL) may be one of the reasons for induction of fatty liver by starvation in suncus. Microsomal triglyceride transfer protein (MTP) is recently proposed to be an important protein during the assembly of plasma VLDL. In this study, the hepatic and intestinal MTP activities in suncus and the effect of nutritional state on them were investigated. The results indicate that the MTP activity in suncus liver was significantly lower than that in rat liver. On the other hand, the basal MTP activity in suncus intestinal mucosa was comparable to that of rat. The hepatic activity was not affected by starvation but was enhanced by refeeding significantly in suncus. This evidence suggests that the low activity of MTP is specific to the liver in suncus and may play a role in induction of fatty liver observed in starved suncus because refeeding led to enhancement of the activity as well as reversal of fatty liver.