Composition of the Dura Mater in Chronic Bovine Hypervitaminosis A

The decreased cerebrospinal fluid (CSF) pressure of chronic hypervitaminotic A animals has been attributed to lowered resistance to bulk absorption of CSF. Since the tentorium cerebelli portion of the dura is a site of bulk absorption, this tissue from 23 male Holstein calves fed for 12 weeks either 54, 108, 8,800 or 17,600 µg of vitamin A per kilogram of live weight/day, was analyzed. Hydroxyproline was not significantly different between calves fed the control intakes (54 and 108 µg) and calves fed the hypervitaminotic levels (8,800 and 17,600 µg). Dry matter of the duras was less in the hypervitaminotic groups as well as total mucopolysaccharides, particularly the chondroitin sulfate fraction. The hypervitaminotic calves had in addition, lower RNA concentrations, greater DNA, smaller ratios of RNA to DNA and slightly lower nitrogen concentrations. The decrease in the mucopolysaccharide matrix of the dural tissue may be responsible for the decreased CSF pressures in vitamin A toxicity.