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.
Itoh
Roichi
R
Department of Home Economics, Tokyo Kasei Gakuin University, 2600 Aiharamachi, Machida-city, Tokyo 194-0292, Japan. roytoh@kasei-gakuin.ac.jp
Kimura
Kayoko
K
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