EFFECT OF INCREASED LEVELS OF ENDOGENOUS NERVE GROWTH-FACTOR ON MOUSE SYMPATHETIC-GANGLIA

Treatment of mice with a range of doses of testosterone propionate [TP] led to significant weight increase of the superior cervical ganglia (SCG). In all cases this was accompanied by elevation of the level of nerve growth factor (NGF) in the submandibular glands (SMG) and, with the exception of animals treated with the lowest dose of TP, by increase of the SMG. Hypertrophy of the SCG was also found in mice treated with 5.alpha.-dihydrotestosterone which therefore excludes the possibility of the hypertrophy being due to a general metabolic effect of TP. Treatment of mice with isoproterenol and of rats with TP resulted in hypertrophy of the SMG but had no effect on levels of NGF in the glands or on the weight of the SCG. These findings exclude the possiblity that hypertrophy of the SCG in TP-treated mice is a consequence of an increase in size of the SMG. Hypertrophy of the SCG In TP-treated mice evidently results from the action of increased levels of endogenous NGF. The route of access of NGF responsible for the hypertrophy is discussed and a comparison is made of the effects produced by systemically administered NGF and increased levels of endogenous NGF.