Marginal zinc deficiency affects maternal brain microtubule assembly in rats

The possible physiological role of Zn in tubulin polymerization was studied. Tubulin assembly in vitro was characterized in brain supernatants from rats fed a marginally Zn-deficient diet (10 micrograms Zn/g) during pregnancy and lactation. The initial rate of tubulin polymerization was significantly lower (27%) in brain supernatants from the marginally Zn-deficient animals than from controls. This was associated with a lower Zn concentration in the brain supernatants from the marginally deficient rats. Total protein and tubulin concentrations were the same in the supernatants from both groups. These data show that Zn is necessary for normal tubulin assembly and indicate that one biochemical defect underlying brain alterations in Zn deficiency could be abnormal microtubule function.