title: Characterization of gamma-glutamyltranspeptidase in the liver of the frog: 1. Comparison to the rat liver enzyme.
abstract: The characteristics of the enzyme gamma-glutamyltranspeptidase were determined in frog liver and compared to those of the rat. In Rana pipiens, tissue distribution studies indicated the order of activity to be: kidney >>> liver >> nerve > egg > lung > heart > skeletal muscle in homogenates. In the Rana pipiens relative to the Fischer 344 rat, the activity of the liver enzyme was somewhat greater (1.8-fold) and the kidney enzyme substantially less (25-fold). Frog liver gamma-glutamyltranspeptidase displayed strain-dependent differences in activity with Rana pipiens and Rana sylvatica exhibiting comparable activities and Xenopus laevis exhibiting 20-fold lower activities. No influence of sex was apparent in Rana pipiens in contrast to the sex dependent differences observed in the Fischer 344 rat: female:male = 7:1. In homogenates and plasma membrane fractions of Rana pipiens, Xenopus laevis and the Fischer 344 rat, high, and comparable relative specific activities, were observed, 8-11, coupled with protein yields of 2.2-2.5 per cent indicating the enzyme to be plasma membrane bound and associated with the sinusoidal surface of the liver cell.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Physiology, College of Medicine, University of Saskatchewan.
authors.forename: S J
authors.initials: SJ
authors.lastname: Sulakhe-Hemmings
authors.forename: H
authors.initials: H
authors.lastname: Xing
mesh_terms: D000818:Animals; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D006358:Hot Temperature; D007555:Isoxazoles / Q000494:pharmacology; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008297:Male; D008298:Maleates / Q000494:pharmacology; D011898:Ranidae / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344 / Q000378:metabolism*; D013045:Species Specificity; D014982:Xenopus laevis / Q000378:metabolism*; D005723:gamma-Glutamyltransferase / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism*
chemical_list: D007555:Isoxazoles; D008298:Maleates; D005723:gamma-Glutamyltransferase; C006303:acivicin