RESUMEN
Certain scrapie strains cause obesity in several strains of mice. The potential association between obesity and altered glucose tolerance was assessed by monitoring body weight and glucose tolerance throughout the incubation period in scrapie strain-mouse strain combinations that do and do not produce obesity. Virtually all obese mice showed reduced glucose tolerance as shown by significantly higher blood glucose levels 2 h after a glucose overload. Mice injected with a scrapie strain that did not cause obesity showed normal tolerance. The scrapie infectivity titre of the pancreas of obese mice clinically affected with scrapie was very low. Adrenalectomy prevented both the increase in weight and aberrant glucose tolerance but had no other effect on the course of the disease. Following increasing dilution of the inoculum, the increase in body weight and the development of aberrant glucose tolerance reached an end-point that was similar to that of scrapie infectivity. The system described provides an inducible model of obesity with altered glucose tolerance.
Asunto(s)
Glucemia/metabolismo , Obesidad/sangre , Priones/fisiología , Scrapie/sangre , Adrenalectomía , Animales , Peso Corporal , Modelos Animales de Enfermedad , Femenino , Prueba de Tolerancia a la Glucosa , Hipotálamo/microbiología , Inyecciones Intraperitoneales , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos , Obesidad/etiología , Páncreas/microbiologíaRESUMEN
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.