TY - JOUR
T1 - Intrathecal methiothepin and thyrotropin-releasing hormone effects on penile erection
AU - Holmes, Gregory M.
AU - Stephens, Robert L.
AU - Bresnahan, Jacqueline C.
AU - Beattie, Michael S.
N1 - Funding Information:
This study was supported by NIH research grant NS-31193 and American Paralysis Association grant no. BA2-9604. The authors wish to thank J.H. Komon, Jr., C.A. Tovar and M.J. Van Meter for their technical assistance.
PY - 2001
Y1 - 2001
N2 - Intrathecal thyrotropin-releasing hormone (TRH) potently inhibits penile erection at all doses (100, 500, 1000 or 5000 pmol) tested so far. Since the serotonin receptor antagonist methiothepin (MT) inhibits TRH responses in other systems, this study tested the hypothesis that MT-sensitive receptors mediate the effect of TRH on penile erection in rats. When compared to controls, the highest doses of IT TRH (0, 10 or 500 pmol) or MT (5 or 50 nmol) significantly altered penile reflex latency. When coadministered (50 nmol MT/500 pmol TRH), the effect of TRH was reversed, suggesting that the high dose of MT antagonized the inhibitory actions of TRH. The low dose of MT (5 nmol) did not block the 500 pmol TRH inhibition of reflex latency. These data further suggest that MT sensitive receptors are important in (1) mediating normal penile reflexes and (2) mediating the inhibitory response to TRH.
AB - Intrathecal thyrotropin-releasing hormone (TRH) potently inhibits penile erection at all doses (100, 500, 1000 or 5000 pmol) tested so far. Since the serotonin receptor antagonist methiothepin (MT) inhibits TRH responses in other systems, this study tested the hypothesis that MT-sensitive receptors mediate the effect of TRH on penile erection in rats. When compared to controls, the highest doses of IT TRH (0, 10 or 500 pmol) or MT (5 or 50 nmol) significantly altered penile reflex latency. When coadministered (50 nmol MT/500 pmol TRH), the effect of TRH was reversed, suggesting that the high dose of MT antagonized the inhibitory actions of TRH. The low dose of MT (5 nmol) did not block the 500 pmol TRH inhibition of reflex latency. These data further suggest that MT sensitive receptors are important in (1) mediating normal penile reflexes and (2) mediating the inhibitory response to TRH.
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U2 - 10.1016/S0031-9384(01)00440-1
DO - 10.1016/S0031-9384(01)00440-1
M3 - Article
C2 - 11399295
AN - SCOPUS:0034992316
VL - 73
SP - 59
EP - 64
JO - Physiology and Behavior
JF - Physiology and Behavior
SN - 0031-9384
IS - 1-2
ER -