Tissue content and metabolism of myo-inositol in normal and lipodystrophic gerbils.

Experiments were conducted to evaluate the effect of diet and sex difference on the development of an intestinal lipodystrophy due to myo-inositol deficiency. Tissue contents of free and lipid-bound myo-inositol as well as the activities of L-myo-inositol-l-phosphate synthase (EC 5.5.1.4) and phosphatase (EC 3.1.3.25), and myo-inositol oxygenase (EC 1.13.99.1) were determined in male and female gerbils under various conditions. The enzyme study proved that the essentiality of dietary myo-inositol for this species was not due to the lack of such enzyme activity. The lower susceptibility of male gerbils to myo-inositol deficiency could be explained by the contribution of the biosynthesis of myo-inositol in the testis, as shown by a difference between intact and castrated animals. Although feeding coconut oil to the myo-inositol-deficient female gerbils produced greater myo-inositol depletion as well as more severe intestinal lesion than the feeding of safflower oil, the difference in myo-inositol status could be only in part responsible for different degrees of lipodystrophy. Additionally, neither dietary type of fat nor exogenous myo-inositol altered the activities of either hepatic or intestinal synthase and phosphatase, or kidney oxygenase. Thus, this study indicates that both sex and dietary factors might influence myo-inositol status to varying extents, but the diet-induced change in tissue myo-inositol was not reflected by the enzyme activity as measured in vitro.