Trace and non-trace elements in blood cells of bottlenose dolphins (Tursiops truncatus): variations with values from liver function indicators.

Alterations in trace and non-trace element homeostasis have been associated with both normal physiologic and pathologic processes of many species. Changes in copper and zinc, for instance, have been associated with liver disease in humans and dogs. While liver disease has been documented in marine mammals, associations of liver disease with trace and non-trace elements have not been determined. The goal of this study was to assess potential elemental associations with clinically relevant changes in liver enzymes of bottlenose dolphins (Tursiops truncatus) and to compare observed associations to what has been reported in other species. Blood cell samples were collected from 37 healthy bottlenose dolphins, maintained by the Navy Marine Mammal Program (MMP), between 1991 and 1992. Twenty-one trace and non-trace elements were assessed along with a standard liver enzyme function profile, and trace element associations to specific liver enzymes were determined. In this study, of the 21 blood cell elements assessed, 19 were measured within detectable limits in at least one of the blood samples, and 10 trace elements were found to be associated with at least one of the liver function indicators. Many of these same associations have been documented in various forms of liver disease in other species, including the associations of increases in copper and decreases in zinc with both elevated alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT). The observed analogous associations between changes in blood trace and non-trace elements and liver function indicators of bottlenose dolphins and other species may indicate similar pathologic processes and functions of some elements. Given the results of this study, additional research is warranted to further elucidate associations of trace and non-trace elements to liver disease in bottlenose dolphins.