Glucuronic acid pathway activity in adipose tissue

Abstract

Paired samples of rat adipose tissue were incubated with glucose-U-C¹⁴ and the effect of unlabeled glucuronolactone on C¹⁴O₂ production from glucose determined. Glucuronolactone significantly diluted C¹⁴O₂ production in tissue from starved or alloxan diabetic rats, but not in tissue from normal fed animals. A dilution effect was observed in tissue from fed rats incubated with growth hormone; this effect was also observed with glucose-6-C¹⁴, but not with glucose-1-C¹⁴. In tissue from starved rats incubated with insulin, glucuronolactone did not dilute C¹⁴O₂ production from glucose. A dilution effect was observed in tissue from normal rats after the injection of growth hormone, or barbital, which is known to stimulate this pathway in liver. The relative significance of the contribution of the glucuronic acid pathway to total CO₂ production from glucose appears to be greater in tissue from starved or diabetic rats than in tissue from normal fed animals; it appears to be increased by growth hormone in vitro or in vivo, but in tissue from starved animals insulin appears to decrease it.