Cortisol and citrate metabolism

¹ Department of Pediatrics, Johns Hopkins University School of Medicine, and the Pediatric Division, Baltimore City Hospital, Baltimore, Maryland

Determinations of citrate concentrations in serum and tissues were made in fluoroacetate-injected rats given cortisol. The increment of serum citrate is less in the cortisol treated rats than in controls injected with fluoroacetate, but the accumulation of citrate in heart and small intestine following fluoroacetate is equally great in both groups. Lower concentrations of citrate in the kidneys of cortisol-treated rats are probably due to differences in citrate of tubular urine. In the adrenalectomized rat fluoroacetate causes a greater rise of serum citrate than in the intact rat but there is no greater increase of tissue citrate. Calculation of citrate distribution ratios, i.e. the ratio of the concentration of citrate in intracellular water to that of extracellular fluid, indicates that the distribution ratio following fluoroacetate is increased by cortisol and decreased by adrenalectomy. Cortisol does not apparently influence the intracellular accumulation of citrate but alters the distribution of citrate between cells and extracellular fluid, possibly due to an effect upon the efflux of citrate from cells.