Environmental contaminants can elicit physiological alterations in alligators. The extent to which such changes are due to developmental exposure and to which they are temporary alterations from later exposure has yet to be determined. Three molecular biomarkers, glutathione-S-transferase (GST), lactate dehydrogenase (LDH), and metallothionein (MT), were evaluated in juvenile alligators from field and developmental studies to determine if developmental toxin exposure induces permanent physiological alterations. Juvenile alligators were collected from contaminated (Apopka) and reference (Woodruff) sites and hepatic GST, LDH, and MT were analyzed. LDH activity and MT levels were elevated in Apopka males, indicating aerobic stress and heavy metal exposure, respectively. GST activity was not significantly different. In the developmental study, eggs were collected from the same sites, incubated, and raised under identical conditions. Hepatic GST, MT and LDH were evaluated for organizational changes. Significant depression of GST activity in Apopka females suggests that GST is altered by developmental contaminant exposure but is elevated to physiologically normal levels in response to post-developmental exposure. LDH and MT did not differ between sites, suggesting they are not developmentally altered but are activated in response to toxins at later life stages.

The Effects of Developmental Contaminant Exposure on Physiology in American Alligators, Alligator Mississipiensis