The influence of insulin on the flux of lipid metabolism in vivo.

The effects of insulin on the balance of lipid metabolism have been investigated by measuring the relative in vivo incorporation of 3H- and 14C-labelled glycerol into the major tissues and lipid classes of diabetic mice over a three day period. Several significant alterations in the relative uptake of label were caused by the insulin treatment. Generally, there were indications of decreased synthesis and degradation of lipids in most tissues, but with an increased synthesis of hepatic triacylglycerol being a notable exception to these trends. These data indicate that insulin treatment produces widespread changes in the relative emphasis of lipid metabolism, and allow a detailed description of these responses in relation to the individual tissues and lipid classes of the living animal. The implications of these metabolic changes have been discussed in relation to hormonal effects, and tissue specific and whole body aspects of the regulation of lipid metabolism.