Some effects of postnatal zinc deficiency on developing rat brain.
A deficiency of dietary zinc during the suckling period of the rat results in a depression in normal growth, which is, in part, due to the inanition experienced by the dam. The pups from such zinc-deficient dams have smaller forebrains at all of the time intervals investigated in comparison with pups from both zinc-adequate controls. The cell number of the forebrain of the zinc-deficient pup was also reduced in comparison with the zinc-adequate pups. RNA concentration did not appear to be affected, although the total RNA content was reduced because of the smaller brain size. The amount of protein per cell was reduced at 6 and 15 days in the zinc-deficient forebrain and polysomal profiles displayed abnormal distribution of material between monosomes and polysomes in the zinc-deficient brain. Zinc deficiency during the suckling period thus appears to disadvantage the animal in terms of body, brain growth, accretion of cells into the forebrain, and normal protein metabolism.