Marginal copper deficiency in rats. Aortal morphology of elastin and cholesterol values in first-generation adult males.

A marginal, 2 parts per million (ppm) copper diet (experimental) was fed to female rats for 4 months prior to breeding, through gestation/lactation, and to the weaned offspring to determine the consequences in adult, male offspring on cholesterol values and aortal morphology. Liver copper concentrations of the dams and pups at day 21 of lactation and of the 117-day-old offspring who consumed the experimental diet were lower (P less than 0.0001) than corresponding rats fed a 10 ppm copper diet (control). However, statistically significant differences due to dietary treatments were not evident in pre- or post-weaning gain in body weight, litter size, cannibalism of pups, or total cholesterol concentrations of the serum and aorta. Ultrastructural examination of experimental offspring aortas revealed focally abnormal features of endothelial cells, the subendothelial space, collagen fibers, smooth muscle cells, and particularly elastin. The ultrastructural irregularities of elastin included discontinuous regions of the internal elastic lamina comprised of stained clumps of elastin of irregular size and shape. The results of this study suggest that a marginal copper nutriture begun in utero will elicit morphologic abnormalities of the aorta in rats that are otherwise without overt signs of copper deficiency.