부산대학교 도서관

The present study was carried out to assess the effects of protease inhibitor (PI) therapy on basal whole body protein metabolism and its response to acute amino acid-glucose infusion in 14 human immunodeficiency virus (HIV)-infected patients. Patients treated with PIs (PI+, 7 patients) or without PIs (PI-, 7 patients) were studied after an overnight fast during a 180-min basal period followed by a 140-min period of amino acid-glucose infusion. Protein metabolism was investigated by a primed constant infusion of L-[1-[sup.13]C]leucine. Dual-energy X-ray absorptiometry for determination of fat-free mass (FFM) and body fat mass measured body composition. In the postabsorptive state, whole body leucine balance was 2.5 times (P < 0.05) less negative in the PI+ than in the PI- group. In HIV-infected patients treated with PIs, the oxidative leucine disposal during an acute amino acid-glucose infusion was lower (0.58 [+ or -] 0.09 vs. 0.81 [+ or -] 0.07 [micro]mol x kg FF[M.sup.-1] x [min.sup.-1] using plasma [[sup.13]C]leucine enrichment, P = 0.06; or 0.70 [+ or -] 0.10 vs. 0.99 [+ or -] 0.08 [micro]mol x kg FF[M.sup.-1] x [min.sup.-1] using plasma [[sup.13]C]ketoisocaproic acid enrichment, P = 0.04 in PI+ and PI-groups, respectively) than in patients treated without PIs. Consequently, whole body nonoxidative leucine disposal (an index of protein synthesis) and leucine balance (0.50 [+ or -] 0.10 vs. 0.18 [+ or -] 0.06 [micro]mol x kg FF[M.sup.-1] x [min.sup.-1] in PI+ and PI- groups respectively, P < 0.05) were significantly improved during amino acid-glucose infusion in patients treated with PIs. However, whereas the response of whole body protein anabolism to an amino acid-glucose infusion was increased in HIV-infected patients treated with PIs, any improvement in lean body mass was detected. leucine kinetics; protease inhibitor therapy; human immunodeficiency virus infection; amino acid requirements