HgCl2 inhibition of D-glucose transport in jejunal tissue from 2 day and 21 day chicks.

Chick jejunal slices that were exposed to HgCl2 exhibited markedly reduced uptakes of D-glucose. The carrier-mediated (phloridzin inhibitable), but not diffusive, component of uptake was affected by Hg. Within each age group, I50 values (concentration of HgCl2 causing 50% inhibition of mediated transport) for slices (mucosal plus serosal exposure) and sacs (mucosal exposure only) were nearly identical; values for brush border membrane vesicles were slightly lower (increased sensitivity). For each preparation, I50 values for 2 day chicks were consistently lower than corresponding values for 21 day chicks. Taken together, these data indicate that the jejunal brush border membrane is a site of HgCl2 action and that membrane sites in tissue from 2 day chicks are more sensitive to Hg than similar sites in tissue from 21 day chicks.