gamma-Glutamyl transpeptidase activity in Ascaris suum

Using histochemical techniques gamma-glutamyl transpeptidase activity has been localized mainly in the cuticle-hypodermis in Ascaris suum. The specific activity of gamma-glutamyl transpeptidase was 3.87 +/- 0.49 mumol h-1 (g tissue)-1 in cuticle-hypodermis as compared to gastrointestinal tract, where it was 0.07 +/- 0.02 mumol h-1 (g tissue)-1, and muscle and reproductive tract where it was less than 0.001 mumol h-1 (g tissue)-1. When cuticle sections were incubated with labelled glutamine a large portion of the glutamine nitrogen was recovered as ammonia which indicated glutamine uptake and utilization by the cuticle-hypodermis. Collectively these histochemical and biochemical data support the fact that gamma-glutamyl transpeptidase activity is found in the cuticle-hypodermis of A. suum and this may be an indication that amino acid absorption could occur through the cuticle via the gamma-glutamyl cycle.