Effects of Thiamine Deficiency and Octanoate Administration,in Vivo,on Gluconeogenesis in Rat Kidney Slices and on Amino Acid Profile in Rat Liver

Abstract

Summary

The effects of a single dose of octanoate (3.7 mmoles/kg, ip) on gluconeo-genesis in kidney slices and on amino acid profile in liver were determined in thiamine-deficient and pair-fed control rats. Kidney slices from the deficient rats produced glucose, from lactate or pyruvate, at greatly reduced rates. Octanoate, in vivo, increased the rates of glucose synthesis in slices from both control and deficient rats.

Thiamine deficiency caused increased levels of threonine and decreased levels of aspartate but glutamate, glutamine, serine, glycine and alanine were unchanged. Octanoate administration, in vivo, to both control and diabetic rats, reduced the concentrations of all liver amino acids, except glycine.

It was concluded that thiamine-deficiency inhibited gluconeogenesis indirectly, possibly via a primary lesion at pyruvate dehydrogenase, but that the inhibition could be circumvented by providing a fatty acid (e.g., octanoate).

This work was supported by Army Research Grant #DAHC 19-68G0039. The authors thank Halvor Sornson for his excellent technical assistance and Dr. W. Ryan for the use of his amino acid analyzer.