myo-Inositol action on gerbil intestine. Association of phosphatidylinositol metabolism with lipid clearance.

The synthesis and turnover of phosphatidylinositol as well as clearance were studied in the intestines of lipodystrophic gerbils treated with or without an intraperitoneal dose of myo-inositol by monitoring the incorporation of 32Pi and the retention of absorbed [1-14C] palmitic acid. 1. myo-Inositol deficiency produced an intestinal lipodystrophy with a large lipid accumulation and a decreased level of phosphatidylinositol. Upon myo-inositol repletion, the intestinal phosphatidylinositol rapidly returned to the control level by h, at which time the removal of excess lipid still remained in a lag phase. 2. myo-Inositol injection caused an increase in the incorporation of 32Pi into phosphatidylinositol mainly due to an increased phosphatidylinositol synthesis de novo. As a result, the turnover of phosphatidylinositol molecules might increase because of an expanded pool size. 3. The stimulation of phosphatidylinositol synthesis was then followed by an enhanced clearance of absorbed [14C] palmitate and by an intestinal recovery which was monitored by the loss of accumulated triacylglycerol. 4. This study indicates that myo-inositol availability appears to regulate the in vivo biosynthesis of phosphatidylinositol which, in turn, may play a crucial role in normal lipid transport across gerbil intestine.