Acute superior cervical ganglionectomy depresses the postcastration rise of gonadotropins in male rats.

In male rats, superior cervical ganglionectomy (SCGx) delayed the rise of serum FSH and LH induced by orchidectomy by 24 h. SCGx resulted in a decrease of median eminence norepinephrine (NE) content 16 h after surgery and in an increase of medio-basal hypothalamic cAMP synthesis and receptor occupancy. These data indicate that NE release from degenerating terminals originating in the superior cervical ganglion neurons modifies the regulatory mechanisms controlling the rise of gonadotropins after orchidectomy in rats.