TY - JOUR
T1 - Effect of rho-kinase inhibition on vasoconstriction in the penile circulation
AU - Mills, Thomas M.
AU - Chitaley, Kanchan
AU - Wingard, Christopher J.
AU - Lewis, Ronald W.
AU - Webb, R. Clinton
PY - 2001
Y1 - 2001
N2 - A recent report from this laboratory (Chitaley K, Wingard C, Webb R, Branam H, Stopper V, Lewis R, and Mills T. Nature Medicine 7: 119-122, 2001) showed that inhibition of Rho-kinase increased the erectile response (intracavernosal pressure and mean arterial pressure) by a process that does not require nitric oxide or cGMP. The present study investigated whether vasoconstrictor agents, which are active in the penis, act via the Rho-kinase pathway. Western analysis revealed RhoA and Rho-kinase protein in the penis. Treatment with the selective Rho-kinase inhibitor Y-27632 significantly increased the magnitude of the erectile response. Intracavernous administration of endothelin-1 (ET-1; 50 pmol) or methoxamine (10 μg/kg) reduced the erectile response to autonomic stimulation. If Y-27632 was given before ET-1 or methoxamine, the vasoconstrictor effect was reduced, and intracavernosal pressure and mean arterial pressure remained elevated. However, when given after methoxamine, Y-27632 had a reduced vasodilatory effect, and Y-27632 had no vasodilatory effect when given after ET-1. These findings suggest that ET-1 and methoxamine increase Rho-kinase activity in the cavernous circulation and support the hypothesis that the vasoconstriction that maintains the penis in the nonerect state is mediated, in part, by the Rho-kinase pathway.
AB - A recent report from this laboratory (Chitaley K, Wingard C, Webb R, Branam H, Stopper V, Lewis R, and Mills T. Nature Medicine 7: 119-122, 2001) showed that inhibition of Rho-kinase increased the erectile response (intracavernosal pressure and mean arterial pressure) by a process that does not require nitric oxide or cGMP. The present study investigated whether vasoconstrictor agents, which are active in the penis, act via the Rho-kinase pathway. Western analysis revealed RhoA and Rho-kinase protein in the penis. Treatment with the selective Rho-kinase inhibitor Y-27632 significantly increased the magnitude of the erectile response. Intracavernous administration of endothelin-1 (ET-1; 50 pmol) or methoxamine (10 μg/kg) reduced the erectile response to autonomic stimulation. If Y-27632 was given before ET-1 or methoxamine, the vasoconstrictor effect was reduced, and intracavernosal pressure and mean arterial pressure remained elevated. However, when given after methoxamine, Y-27632 had a reduced vasodilatory effect, and Y-27632 had no vasodilatory effect when given after ET-1. These findings suggest that ET-1 and methoxamine increase Rho-kinase activity in the cavernous circulation and support the hypothesis that the vasoconstriction that maintains the penis in the nonerect state is mediated, in part, by the Rho-kinase pathway.
KW - Endothelin-1
KW - Methoxamine
KW - Penile erection
KW - Penis
KW - Vasodilation
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U2 - 10.1152/jappl.2001.91.3.1269
DO - 10.1152/jappl.2001.91.3.1269
M3 - Article
C2 - 11509525
AN - SCOPUS:0034863248
SN - 8750-7587
VL - 91
SP - 1269
EP - 1273
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 3
ER -