ERYTHROCYTE METALLOTHIONEIN IN RELATION TO OTHER BIOCHEMICAL ZINC INDEXES IN PREGNANT AND NONPREGNANT WOMEN

Erythrocyte metallothionein (E-MT) is considered a promising index of zinc status in humans, since it may be more sensitive than other bioch emical indices to changes in dietary zinc. However, conditions of high zinc demand with substantial redistribution of tissue zinc and specif ic changes in hormone profile, such as pregnancy, may have an influenc e on E-MT levels in addition to dietary zinc. In this study, Mie compa red E-MT concentrations in relation to other biochemical zinc indices in healthy pregnant women at delivery (n = 40) and nonpregnant women ( n = 22) with similar habitual dietary zinc intakes (average 13.3 mg/d) . Pregnant women had lower serum zinc and albumin-bound serum zinc, bu t higher levels of alpha 2-macroglobulin-bound serum zinc than the non pregnant women. Erythrocyte zinc (E-Zn) was similar in both groups, bu t E-MT (mean +/- SE) was slightly but significantly (p < 0.05) higher in the pregnant women (2.9 +/- 0.09 nmol/g protein) compared to nonpre gnant women (2.6 +/- 0.06 nmol/g protein). A significant correlation w as observed between E-MT and E-Zn in the nonpregnant women (r = 0.70; p < 0.001), consistent with the role of intracellular zinc in the regu lation of metallothionein synthesis. However, such correlation was not observed in the pregnant women, suggesting that E-MT levels in pregna ncy may be influenced by factors related to the pregnant state.