Lipogenesis from [2- 14 C] Glucose in Squirrel Monkeys

Abstract

Summary

[2-¹⁴C] Glucose was injected into squirrel monkeys (Saimiri sciurea), tissues were removed and frozen at 20 min, and analyzed for the incorporation of ¹⁴C into lipids. The specific activity of radiosubstrate incorporation was 2.5-16 times greater into adipose tissues than into liver. There were significant differences among adipose tissues in the distribution of ¹⁴C in triglycerides and phospholipids and also among that incorporated into the glycerol versus fatty acid moieties of triglycerides. Of the ¹⁴C present in all triglycerides and in liver phospholipids, 56-76% was in the fatty acid moiety, whereas only 14-31% of the ¹⁴C was present in the fatty acids of the adipose tissue phospholipids. There were significant differences between liver and adipose tissues as well as among some of the adipose tissues. Fatty acids 14:0, 16:0, and 16:1 were synthesized dc novo whereas no more than half of 18:0 and 18:1 would have arisen by de novo synthesis. [2-¹⁴C] Glucose can be a useful metabolite for in vivo lipogenic studies when there is concomitant understanding of the specific location of the ¹⁴C within the lipids.

I thank Lynne Bonnett and JoAnn Wolff for their technical assistance. This work was supported by U.S. Public Health Service Grants No. AM-12601 (C.F.H.), HE-09744 (Dr. O. W. Portman), and RR-00163 (Oregon Regional Primate Research Center). Publication No. 632 from the Oregon Regional Primate Research Center.