INCREASED PLASMA-GLUCOSE LEVELS AFTER HYPNORM(R) ANESTHESIA, BUT NOT AFTER PENTOBARBITAL(R) ANESTHESIA IN RATS

The effects of the fentanyl fluanisone combination (Hypnorm(R)) and pe ntobarbitone sodium (Pentobarbital(R)) anaesthesia on blood glucose, i nsulin and glucagon were tested in rats in the fed and fasted state. B lood glucose was measured before and at 10, 20 and 30 min after inject ion of the anaesthetic agents. At 30 min the rats were sacrificed, and blood was drawn for measurement of glucagon and insulin. Pre-anaesthe tic values for insulin and glucagon were established in separate group s of fasted and fed rats. In fasting rats given Hypnorm(R), blood gluc ose and plasma insulin were unchanged while there was a non-significan t increase in plasma glucagon. The fasted rats given Pentobarbital(R) had unchanged blood glucose and plasma insulin and a non-significant d epression of glucagon. The fed rats given Hypnorm(R) had a significant increase in blood glucose at 10 min and nearly a doubling of glucose values at 20 and 30 min (P < 0.001). Glucagon increased far less than in the fasted group, whereas insulin was doubled from preanaesthetic v alues (P < 0.05). The fed rats given Pentobarbital(R), had unchanged b lood glucose, a slight non-significant depression of glucagon and a si gnificant increase in insulin (P < 0.01). Thus Hypnorm(R) induced hype rglycaemia in fed but not in fasted rats, probably because more glucos e was available in the fed state. Fed animals are a modification of th e standard fasted animal model, and may be preferable when exploring h yperglycaemic or other reactions to anaesthetic agents.