“ blocker , during preincubation for 45 min reduced the tissue concentrations (pmol/mg protein) of gamma-glutamylglutamate (… (+ acivicin)), gamma-glutamylglutamine (40.3 +/- 6.7 vs. 25.7 +/- 4.2 pmol/mg protein), glutamine (9.9 +/- 2.0 vs. 4.6 +/- 1.2 … vs. 0.56 +/- 0.18 nmol/mg protein).”