Iperplasia Collaterale Nella Oncogenesi Sperimentale Del Ratto: Rilievi in corso di trattamento con Vitamina A

33 rats were inoculated with 10 mg of 3,4-benzpyrene. One month later, 18 of them were orally treated with 1000 I.U. of vitamin A weekly. After the tumour had developed, skin fragments from the area overlying the tumor and from the contralateral region were removed. In comparison with the controls not treated with vitamin A, it was observed 1) a reduction of the hyperplastic-dysplastic phenomena associated with hair hypoplasia and hypotrophy, both on the skin overlying the tumor and, to a less extent, in the apposite side, 2) a moderate reduction of the epidermal activity, 3) a marked decrease of hyperplasia and hypertrophy of the sebaceous glands, and 4) a more pronounced fibrillogenesis in the tumour capsule.