Congenital hypothyroidism in latent obese (ob/ob) mice.

Activity of thyroid glands in latent-obese baby mice is below that of normal ones from birth on. Maturation of certain features, such as pinnae freeing, eye and ear opening, eruption of lower incisor teeth, is delayed in latent obese mice. After thyroxin injections maturation is normalized. Data support the hypothesis that the obese hyperglycemic syndrome in mice is characterized by congenital hypothyroidism.