McComb-Renjifo A, Ange-van Heugten K, Valdes EV, Luginbuhl JM. 2011. Evaluation of Carotene 15, 15’-Monoozygenase conversion in two anura species. In Ward A, Coslik A, Maslanka M, Eds. Proceedings of the Ninth Conference on Zoo and Wildlife Nutrition, AZA Nutrition Advisory Group, Kansas City, MO.
It is unknown whether pro-vitamin A supplements used in captive diets of amphibian insectivores provide the animals with nutrients they can convert for their vitamin A needs. This research sought to evaluate if activity of ?–carotene 15,15’-monooxygenase was present in the liver and small intestine of two anura species, as gauged by the conversion of ?–carotene to retinal. Liver and small intestine from wild adult cane toads (Bufo marinus; n=9) and Cuban tree frogs (Osteopilus septentrionalis; n=3) were processed to achieve an enzyme fraction and then incubated at 37C for 30 minutes with either a blank (hexane) or treatment (?–carotene in hexane) solution. Chicken duodenum and liver were used as comparison standards. Reverse phase-high performance liquid chromatography was used to quantify the retinal found. There was no difference in the amount of retinal found between the blank and ?–carotene treatment samples of anura livers (2.61 and 3.45 pmol/mg protein/30min, respectively; P = 0.7469) and small intestines. The lack of conversion suggests the inability of these species to use ?–carotene as a vitamin A source in their fully metamorphosized, adult life stage. These findings warrant further investigation on the conversion capability of other amphibian species and also their various life stages.22_McComb.pdf     86 KB