Effect of diphenylhydantoin administration on the growth of the functional components of rat skull.

With the purpose of studying the effect of diphenylhydantoin (DPH) administration on the growth of the functional components of the rat skull, male Wistar rats weighing 61.6 +/- 0.6g were assigned to 1 out of 4 different groups. One of them received saline and was taken as normal control. The others were injected once daily with 25, 50 or 100 mg/kg of b.w. of DPH i.p. for 20 days. Another group of rats was put under a restricted diet (RD) (20% of normal intake) for the same time for evaluation of the cranial dimensions. On day 21 the rats were killed by ether overdose and fifteen cranial dimensions were evaluated as previously described employing Pucciarelli's method. The body weight gain of DPH injected rats was up to 20.7% lower independently of drug dose. The rats of the RD group showed a similar reduction. The amount of food consumed by DPH rats was 16% lower than that consumed by controls independently of drug doses. The concentration of alkaline phosphatase and hemoglobin in rats treated with 50 or 100 mg/kg b.w. of DPH was lower than in controls and RD-animals. However, urea and total calcium in plasma were unchanged in DPH-treated rats as compared to controls. Mean appetite quotient, efficiency of protein and energy utilization did not appear to change in response to the treatment with DPH or maintained under a restricted diet. The cranial dimensions of rats, injected with 25 mg/kg b.w. of DPH were not statistically different from those of the control and RD-groups. When the dose of DPH injected was 50 mg/kg b.w. the neurocranial width and height and the spachnocranial length were significantly lower than controls and RD-values. Moreover, all the dimensions corresponding to neurocranium and splachnocranium (width, height and length) of the rats injected with 100 mg/kg b.w. of DPH were significantly lower than those of control and RD-groups. The disharmonius growth of the skull do not appear to be dependent on suboptimal energy intake, efficiency of protein, energy utilization renal failure and anemia.