The Insulin Resistance And The Changes Of Expression Of Insulin Receptor MRNA Of Leukocytes During Normothermic CPB In Infants And Young Children

Objective: To observe the plasma glucose (Glu) and insulin (Ins) levels, andcalculate the insulin sensitivity index [1/ ( I × G ) ]during normothermic cardiopulmonary bypass (CPB) to observe the procedure of insulin resistance associated with CPB in infants and young children. And by observing the alteration of the expression of the insulin receptor mRNA in peripheral leukocytes as the target cells by the In Situ Hybridization (ISH) , to discuss the molecular biological mechanism at genic transcription level and its the accepted meaning on clinic during CPB in young babies.Methods: 30 infants and young children with congenital heart disease of left toright shunt were tested by drawing respectively the heparinized blood samples for plasma glucose and insulin level at the time spot in every 15minutes after anesthesia induction(T₁), 15minutes after CPB(T₂),10 minutes after aortic declamping(T₃), 30 minutes after weaning off pump(T₄), 6 hours after operation(T₅), 24 hours after operation(T₆). Calculate the insulin sensitivity index [1/ (I×G) ] at each time spot. And investigate the expression of insulin receptor mRNA of peripheral white blood cells by the In Situ Hybridization (ISH) and the relations to the changes of plasma glucose, insulin, and insulin sensitivity index.Results: The plasma glucose was increased since starting CPB (P <0.01), and at its peak 10min after declamping of aorta(P <0.01). The insulin was increased afterstarting CPB (P <0.01), and at its peak at 30min after weaning off CPB (P <0.01), and dropped down gradually in 6 hours after the operation, until 24 hours postoperatively it is still slightly higher than that of preoperation. The significant decrease of insulin-sensitivity index was observed at 30min after ending CPB(P <0.01). ISH shows that the expression of insulin receptor mRNA of peripheral leucocytes is obviously inhibited during CPB(P <0.01), and recoveries gradually 6 hours after the cardiac surgery^ <0.01).Cone I us i ons:1. There is no significant inhibition on the insulin secretion of pancreas of the infants and young children during normothermic cardiopulmonary bypass.2. The insulin resistance can be observed during this procedure because of the strong stress.3. The expression of insulin receptor mRNA of peripheral leukocytes shows an obvious decrease during normothermic CPB and a close relationship with the changes of plasma glucose, insunlin and the insulin sensitivity index.4. The insulin resistance should be considered and treated properly in these infants and young children with congenital heart disease on normothermic CPB.