The Effect of Methyl-Prednisolone on the Turnover of Lactate and the Conversion of Lactate to Glucose in Dogs

Abstract

The effects of methyl-prednisolone on the turnover of lactate and the incorporation of carbon atoms from plasma lactate into glucose have been studied in non-anaesthetized dogs by a tracer method using L-(+)-lactate-U-¹⁴C as tracer. Treatment with 4 mg/kg.day methyl-prednisolone for 7 days caused a sevenfold increase in the concentration of lactate in the blood plasma and a threefold increase in the rates of lactate production and utilization. Identical fractions of the carbon atoms utilized as lactate were incorporated into the 6th carbon atoms of circulating glucose molecules before and after the treatment with steroids. Thus lactate is not utilized preferentially as substrate for the increased gluconeogenesis caused by the steroid. The ratio of total ¹⁴C incorporated into circulating glucose and the ¹⁴C incorporated into the 6th carbon atom was found to be 5:1. This ratio was not changed significantly by steroid treatment.

Key words

Turnover of Lactate - Lactate-Glucose Transformation - Methyl-Prednisolone - Adrenal Cortex