BLOOD AND TISSUE ENZYME ACTIVITIES IN BEARDED DRAGONS (POGONA VITTICEPS)

Bearded dragons (<i>Pogona vitticeps</i>) are a common reptile species kept under human care and suffer from a wide range of diseases for which plasma biochemistry is used as a first-line diagnostic test. There is limited information available regarding tissue enzyme activities and origin that could assist in interpreting the bearded dragon plasma biochemistry enzymology profile. The aim of this study was to characterize the tissue activities of seven enzymes routinely used in the reptile biochemistry panel: alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), glutamate dehydrogenase (GLDH), lactate dehydrogenase (LDH), and creatine kinase (CK) in 12 adult inland bearded dragons in 13 tissues, plasma, and red blood cells. CK activity was highest in skeletal muscle followed by cardiac muscle; ALT and AST were distributed in several tissues and were relatively non-specific for all organs, additionally hepatic fat accumulation reduced AST hepatic activity on a weight per weight basis. ALP and GGT activities were mostly high in the kidneys; LDH activity was elevated in cardiac muscle and skeletal muscle followed by liver; and GLDH had primarily high enzyme activities in liver. Low red blood cell enzyme activities suggest that hemolysis is unlikely to artifactually increase AST or LDH plasma concentrations. These results provide a stepping stone to improve the interpretation of biochemistry results in bearded dragons, especially as it compares to other reptile species.