Inhibition of protein breakdown by glutamine in perfused rat skeletal muscle

AbstractWe have assessed the effects of glutamine (Gln) availability on protein breakdown in perfused rat hindlimb by measuring net phenylalanine (Phe) production (an index of protein balance), the dilution of [15N]Phe labelling (an index of mixed protein breakdown) and rate of production of 3-methylhistidine (3-MeH) (an index of myofibrillar breakdown). 15 mM Gln significantly inhibited net protein loss and protein breakdown compared to rates obtained in its absence (net protein loss, 200±230 vs 2080±200 nmol Phe/hindlimb per h; protein breakdown, 4566±480 vs 1614±180 nmol Phe/hindlimb per h; both p