Journal of Neuroscience, Vol 7, 1607-1612, Copyright © 1987 by Society for Neuroscience
The major pelvic ganglion: androgen control of postnatal development
JE Melvin and RW Hamill
Previously we reported the effects of postnatal castration on the
postorganizational development of the sympathetic hypogastric ganglion
(Hamill and Guernsey, 1983; Melvin and Hamill, 1986). "Postorganization"
implies an activational role for gonadal hormones, in contrast to the
permanent organizing effects that occur perinatally. We now report results
that suggest that the major pelvic ganglion (PG), a mixed parasympathetic
and sympathetic ganglion, is similarly regulated by testosterone during
development. Choline acetyltransferase (CAT) and tyrosine hydroxylase
(T-OH) activities were used to examine normal PG ontogeny. The normal
development of these biochemical indices occurs primarily after day 10.
Postnatal castration at 10-11 d of age completely prevented the
postorganizational developmental increase of T- OH activity. At 12
postoperative weeks T-OH activity in castrates was approximately 6% that of
the control animals (control, 2880 +/- 127 pmol/ganglion X hr; castrated,
161 +/- 16 pmol/ganglion X hr; p less than 0.001). In fact, by only 1
postoperative week, T-OH activity was already significantly reduced in
castrated animals (control, 480 +/- 69 pmol/ganglion X hr; castrated, 179
+/- 6 pmol/ganglion X hr; p less than 0.001). CAT activity and total
ganglion protein were also significantly reduced by 1 postoperative week.
In contrast to T-OH activity, however, these indices continued to develop
at diminished rates. By 12 postoperative weeks CAT activity and total
ganglion protein in castrates were 30 and 50% of control values,
respectively, resulting in a significant developmental abnormality in
CAT-specific activity. Testosterone replacement reversed the
castration-induced developmental deficits of T-OH and CAT
activities.(ABSTRACT TRUNCATED AT 250 WORDS)