IMP-GMP 5'-nucleotidase in reptiles: occurrence and tissue distribution in a crocodile and three species of lizards.
IMP-hydrolyzing activity (which is reactive with goose anti-pig lung IMP-GMP 5'-nucleotidase (c-N-II: EC.3.1.3.5) serum) was detected in extracts from several tissues (liver, heart, kidney, spleen, stomach, lung and skeletal muscle) from constitutively uricotelic reptiles: a crocodile (Crocodylus siamensis), and three species of lizard (Furcifer oustaleti, Tupinambis rufescens and Varanus gouldi). The activities were markedly high in the livers: 3.0 units/g in the crocodile and 1.4-2.9 units/g in the lizards. These were similar to those previously reported for the livers from chicken and snakes (also constitutively uricotelic), and 4- to 10-fold higher than those in ammoniotelic or ureotelic vertebrates. These findings suggest that the high activity of IMP-GMP 5'-nucleotidase in the liver is a feature of constitutive uricotelism, and that the enzyme may participate in the production of uric acid as an end product of amino acid catabolism.
Department of Home Economics, Tokyo Kasei Gakuin University, 2600 Aiharamachi, Machida-city, Tokyo 194-0292, Japan. roytoh@kasei-gakuin.ac.jp
Roichi
R
Itoh
Kayoko
K
Kimura
D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000737:chemistry / Q000378:metabolism*; D000489:Alligators and Crocodiles; D000818:Animals; D001391:Azo Compounds / Q000494:pharmacology; D004396:Coloring Agents / Q000494:pharmacology; D006868:Hydrolysis; D007291:Inosine Monophosphate / Q000737:chemistry*; D007668:Kidney / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D008116:Lizards; D009708:Nucleotidases / Q000378:metabolism; D013045:Species Specificity; D014018:Tissue Distribution
D001391:Azo Compounds; D004396:Coloring Agents; D007291:Inosine Monophosphate; D009708:Nucleotidases; D015106:3',5'-Cyclic-GMP Phosphodiesterases