The effect of betamethasone on glucose utilization and oxidation by sheep.

Abstract

SUMMARY Continuous infusions of tracer amounts of [U-14C]glucose were used to measure the effect of a single intramuscular injection of 0·5 mg betamethasone/kg on the rates of glucose entry in six sheep eating 900 g/day chopped hay containing 49 g protein. In four of the sheep the rates of oxidation of glucose to CO2 were also measured. Hyperglycaemia occurred with a maximum plasma glucose concentration occurring 24 h after administration of the steroid. The mean glucose entry rates, expressed as mg/min/kg ± s.e.m., rose from 1·27 ± 0·11 (6) to 1·75 ± 0·16 (6). The difference between these means is significant (P < 0·001). The mean proportion of CO2 derived from glucose after administration of betamethasone (11·64 ± 1·4% (4)) was not significantly different (P > 0·5) from that derived before its administration (12·47 ± 0·34% (4)). The amounts of glucose available for synthetic purposes increased because the total production rates increased. The mean extra amount available was 11·3 ± 2·1 (4) mg C/min. These results are discussed in the light of other findings relating to the actions of the glucocorticosteroids on glucose metabolism.