Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: 3/14/2003
Publication Date: 3/14/2003
Citation: Orellana, R.A., O'Connor, P.M., Nguyen, H.V., Bush, J.A., Thivierge, M.C., Suryawan, A., Liu, C.W., Fiorotto, M.L., Davis, T.A. 2003. Modulation of muscle protein synthesis by insulin is maintained during acute neonatal endotoxemia [abstract]. Federation of American Societies for Experimental Biology Conference. Part I, 17(4):A739. Interpretive Summary: Not needed for an Abstract
Technical Abstract: Sepsis promotes insulin resistance and reduces protein synthesis in skeletal muscle of adults. The effect of sepsis on insulin-stimulated muscle protein synthesis has not been determined in neonates, a highly anabolic population that is uniquely sensitive to insulin. Neonatal pigs were infused for 8 h with endotoxin [LPS, 0 and 10 ug/(kg.hr)]. Glucose and BCAA were maintained at fasting levels, insulin was clamped either at fasting or fed (2 or 10 uU/ml) levels, and fractional protein synthesis rates (FSR) were determined after 8 hours. LPS infusion induced a septic-like state as indicated by a sustained elevation in body temperature, heart rate, and cortisol. In the presence of fasting insulin levels, LPS reduced FSR in longissimus dorsi (LD, -29%) and gastrocnemius (-27%), had no effect on masseter, and stimulated FSR in liver (+27%). Increasing insulin to fed levels accelerated FSR in LD (controls, +44%; LPS +54%), gastrocnemius (controls, +43%; LPS +70%) and diaphragm (controls, +66%; LPS +81%), and the response to insulin was similar in LPS and controls. Insulin did not alter FSR in liver, kidney, and jejunum in both groups. These findings suggest that acute endotoxemia moderately lowers basal fasting muscle protein synthesis in neonates, but does not alter their high sensitivity and responsiveness to insulin.