Adrenal involvement in scrapie-induced obesity.

In previous studies we found an increase in body weight during the preclinical phase of disease in certain scrapie strain-mouse strain combinations. The effect was augmented by injection into the hypothalamus. In the present study, we found an increase in food consumption (compared to the normal mouse brain injection group) for both the 139A and ME7 scrapie groups, although only the ME7 group showed an increase in body weight. In a scrapie strain-mouse strain combination that showed an increase in body weight, the adrenal gland was the only organ that showed a significant increase in weight. The titer of scrapie in the adrenals was comparatively low. Adrenalectomy prevented the increase in body weight in two strains of mice injected with the ME7 scrapie strain. The results suggest that scrapie-induced obesity depends on an effect of scrapie on the hypothalamic-pituitary-adrenal axis.