Lm. Freeman et al., DISTRIBUTION OF ANDROGEN RECEPTOR IMMUNOREACTIVITY IN THE SPINAL-CORDOF WILD-TYPE, ANDROGEN-INSENSITIVE AND GONADECTOMIZED MALE-RATS, Journal of neurobiology, 27(1), 1995, pp. 51-59
The polyclonal antiserum PG21 was used to detect androgen receptor (AR
) protein in three motoneuronal pools of the male rat lumbar spinal co
rd, In gonadally intact, wild-type males, the spinal nucleus of the bu
lbocavernosus (SNB), dorsolateral nucleus (DLN), and retrodorsolateral
nucleus (RDLN) all displayed immunolabeling of cell nuclei. The perce
ntage of motoneurons displaying such labeling was highest in the SNB a
nd lowest in the RDLN, This pattern of AR immunocytochemical labeling
agrees well with previous steroid autoradiographic studies of androgen
accumulation in the rat spinal cord, In contrast, virtually no motone
urons in any of the three pools displayed nuclear AR immunostaining in
longterm gonadectomized males or in gonadally intact males carrying t
he Tfm mutation, which renders the AR incompetent, In gonadectomized m
ales, labeling was restored in the SNB and DLN, but not the RDLN, 30 m
in after an injection of replacement testosterone. Eight hours of test
osterone exposure restored immunolabeling in all three motor nuclei, A
pparent cytoplasmic staining was seen in SNR motoneurons of untreated
castrates and Tfm rats, but not intact rats, suggesting that AR residi
ng in the cytoplasm translocates to the nucleus on binding to androgen
in these motoneurons. (C) 1995 John Wiley and Sons, Inc.