RESUMO
Zinc and copper are components of many enzymes. Little information exists on the levels of trace elements in the plasma of the Mongolian gerbil (Meriones unguiculatus). We studied the age- and gender-related differences in the plasma Zn and Cu levels of healthy Mongolian gerbils. The 30 male and 30 female animals were allocated into three age groups (group A, 90 days old; group B, 180 days old; and group C, 360 days old), with 10 animals of each gender per group. They were housed under standard conditions with free access to pelleted rodent-maintenance diet (Zn, 95 mg/kg; Cu, 30 mg/kg) and water (Zn, undetectable; Cu, < 0.45 mg/liter). Overall, plasma Cu levels (mean 1 standard deviation) were significantly higher in female (2.03 0.41 mg/ml) than male (1.30 0.28 mg/ml; P < 0.0001) gerbils. Among the male rodents, those in group B had the lowest Cu levels, whereas among the females, the lowest values were in group A. In contrast, plasma Zn levels did not differ between genders (males, 2.96 0.43 mg/ml; females, 2.96 0.38 mg/ml) or age groups. In general, plasma Cu and Zn levels were higher in gerbils than rats. We conclude that gerbils may be an interesting model for studying the metabolism of these trace elements.