Comparison of the carcinogenicity of methylazoxymethanol-beta-D-glucosiduronic acid in conventional and germfree Sprague-Dawley rats.

Methylazoxymethanol-beta-D-glucosiduronic acid (MAM-GlcUA) was administered to young adult male Sprague-Dawley rats by oral and ip routes. Most neoplasms developed in rats that had received the compound orally. The most prevalent site for the neoplasms was the intestinal tract, predominantly the colon.

Granular cell tumors of the central nervous system of rats.

On the basis of our study of 12 cases of granular cell tumors in the brains of rats of different inbred strains, it seems that granular cell tumors are not rate in the central nervous system of untreated, aging BN/Bi rats. In none were metastases found. Awareness of the occurrence of these tumors in the central nervous system of these rats may stimulate further studies into the cellular origin of granular cell tumors that form in the central nervous system of the rat and might help to elucidate the origin of these tumors in general.

Intellectual deficit associated with transplacentally induced microcephaly in the rat.

Fischer rats injected with methylazoxymethanol late in pregnancy produce young with considerably reduced cerebral hemispheres. They appear normal otherwise. As adults these animals make many more errors in the Hebb-Williams maze than do control animals.

Tumor induction in germfree rats with methylazoxymethanol (MAM) and synthetic MAM acetate.

The glucoside cycasin, an effective hepatotoxin and carcinogen in conventional rats, fails to produce these effects when administered to germfree rats. The hepatotoxic and carcinogenic effects of cycasin can also be elicited after prior hydrolysis to the aglycone. The aglycone (MAM) and the synthetic aglycone acetate ester produce all the effects in germfree rats of which the intact glucoside is capable only when fed to conventional rats.

THE BRAIN LESION OF GOLDTHIOGLUCOSE OBESITY.

The development of hypothalamic lesions due to goldthioglucose are described. The initial extensive necrotic lesion occurs in close to 100 per cent of animals injected with LD(50). Within 2 weeks the necrotic material has been removed and a narrow scar results.