The effects of dehydroepiandrosterone (DHEA)/DHEA-sulfate (DHEAS) on the contraction responses of the clitoral cavernous smooth muscle from female rabbits.
BACKGROUND
Dehydroepiandrosterone (DHEA) is a multifunctional steroid that is increasingly available as a supplement aimed at improving libido and well-being in postmenopausal women in the recent times. Together with its sulfate version, DHEA-sulfate (DHEAS), it is the most abundant steroid in humans. The clitoris is an important component of the female sexual response, with its increased vascular response during sexual arousal that results in erection.


OBJECTIVE
To elucidate the direct effects of DHEA/DHEAS on the vasomotor reactivity of the rabbit clitoral cavernosum.


METHODS
Twenty New Zealand white female rabbits weighing approximately 2.5-3 kg were used in the study.


METHODS
The contractile response of clitoral cavernous smooth muscle strips in response to phenylephrine (PE; 10(-9)-10(-4) M) were observed in rabbits. Additionally, DHEA/DHEAS effects on phenylephrine-induced contraction and/or acetylcholine-induced relaxation of phenylephrine-induced contraction were measured.


RESULTS
DHEA/DHEAS did not elicit any remarkable response in the resting state. However, both DHEA and DHEAS evoked dose-dependent relaxations of PE-induced contraction. The contractile responses to high potassium were significantly decreased in the DHEA/DHEAS-pretreated strips, compared with the DHEA/DHEAS-nontreated strips. Additionally, contractions by Bay K 8644 (10(-7)-10(-6) M) treatment were also significantly inhibited by DHEA/DHEAS. DHEA-induced relaxation responses were stronger than DHEAS-induced relaxation responses. Various K channel blockers, tetraethylammonium (TEA; 1 mM, 10 mM), 4-aminopyridine (10 microM) and glibenclamide (10 microM) did not affect the DHEA/DHEAS-induced relaxation on muscle strips contracted by PE. Relaxation responses by acetylcholine or sodium nitroprusside (SNP) were not changed after DHEA/DHEAS pretreatment.


CONCLUSIONS
DHEA/DHEAS was found to induce a relaxation response in rabbit clitoral cavernosal smooth muscle, and this is thought to be mediated by direct inhibition of a voltage-dependent calcium channel.
Lee
Shin Young
SY
Chung-Ang University College of Medicine-Department of Urology, Seoul, Korea.
Myung
Soon Chul
SC
Lee
Moo Yeol
MY
Kim
Tae Hyoung
TH
Kim
Sae Chul
SC
Kim
Kyung Do
KD
Park
Soo Hyun
SH
Kim
Won Yong
WY
D000704:Analysis of Variance; D000818:Animals; D001143:Arousal / Q000187:drug effects; D015220:Calcium Channels / Q000187:drug effects; D002987:Clitoris / Q000187:drug effects*; D003687:Dehydroepiandrosterone / Q000494:pharmacology; D019314:Dehydroepiandrosterone Sulfate / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D011817:Rabbits; D012726:Sexual Behavior, Animal / Q000187:drug effects; D014666:Vasomotor System / Q000187:drug effects
D015220:Calcium Channels; D003687:Dehydroepiandrosterone; D019314:Dehydroepiandrosterone Sulfate