Plasma iron, copper, and zinc in lizard Dipsosaurus dorsalis: effects of bacteria injection.

The effects of inoculation of desert iguanas (Dipsosaurus dorsalis) with heat-killed Aeromonas hydrophila on the plasma concentrations of iron, copper, and zinc, and the total iron-binding capacity have been determined. Plasma iron concentration and total iron-binding capacity fell significantly in inoculated lizards maintained at temperatures corresponding to those selected during fever. Plasma copper concentration did not change in response to inoculation (as determined at 24 h postinjection). Plasma zinc concentration fell in inoculated lizards regardless of whether the lizards were maintained at temperatures corresponding to those selected by afebrile or febrile lizards. There were no effects of varying the zinc concentration (corresponding to those observed in noninfected lizards, infected lizards, or at subnormal levels) on the in vitro growth rate of A. hydrophila. We hypothesize that the reduction in plasma zinc observed in infected mammals, and now in infected lizards, may have an effect (perhaps by some indirect pathway) on the in vivo growth rate of A. hydrophila.