Myocardial insulin resistance during acute endotoxin shock in XXXX .

@entity4485 @entity2491 @entity296 @entity697 @entity235 @entity26 @entity12870 @entity413
Myocardial insulin responsiveness was determined in open-chest @entity4485 -anesthetized @entity235 before and after endotoxin administration. Animals were instrumented to measure mean arterial blood pressure (MABP), heart rate (HR), and coronary blood flow. Myocardial @entity413 uptake and myocardial @entity26 uptake (MVO2) were determined during a basal control period and after a @entity12870 over a wide range of insulin concentrations. The clamp was accomplished by intravenously infusing insulin (0-4000 mU/min) and 20% @entity413 in sufficient amounts to maintain arterial @entity413 concentrations within 5 mg/dl of the control value. In a separate series of experiments, @entity296 responsiveness was determined by use of a single dose of insulin (4000 mU/min). This was done to determine whether antecedent insulin infusions during the sequential clamp procedure would affect the responsiveness of the heart. In control experiments, myocardial @entity413 uptake increased without any changes in HR, MVO2, or MABP. Maximum myocardial @entity413 uptake occurred at an insulin infusion rate between 400 and 4000 mU/min. A single concentration of insulin resulted in similar increases in myocardial @entity413 uptake as with the sequential clamp protocol. @entity697 was induced by bolus injection of 1 mg/kg @entity2491 endotoxin (Difco Labs, Detroit, MI). One hour after administration of endotoxin, basal myocardial @entity413 uptake was decreased compared with the control animals. After 1 h of endotoxin shock, the heart was refractory to all concentrations of insulin, suggesting the site for altered insulin response was being mediated by a postreceptor mechanism.
