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ABSTRACT: Introduction
Hydrochlorothiazide has a negative influence on penile erection but little is known about the mechanism(s) involved.Aims
To characterize the effects of this diuretic on mouse corpus cavernosum (CC) smooth muscle in vitro and ex vivo.Methods
CC strips of C57BL/6 mice (12-16 weeks old) were mounted in organ baths containing Krebs-Henseleit solution and tissue reactivity was evaluated. Expression of genes encoding diuretic targets and enzymes involved in penile erection were evaluated by polymerase chain reaction.Main outcome measures
Stimulation-response curves to phenylephrine (10 nmol/L-100 ?mol/L) or to electrical field stimulation (1-32 Hz) were constructed, with or without hydrochlorothiazide. Strips of CC from mice after long-term hydrochlorothiazide treatment (6 mg/kg/day for 4 weeks) with or without amiloride (0.6 mg/kg/day for 4 weeks) in vivo also were studied. Nitric oxide and Rho-kinase pathways were evaluated.Results
Hydrochlorothiazide (100 ?mol/L) increased the maximum response to phenylephrine by 64% in vitro. This effect was unaffected by the addition of indomethacin (5 ?mol/L) but was abolished by N((?))-nitro-L-arginine methyl ester (100 ?mol/L). Hydrochlorothiazide (100 ?mol/L) potentiated electrical field stimulation-induced contraction in vitro, but not ex vivo. Long-term treatment with hydrochlorothiazide increased the maximum response to phenylephrine by 60% and resulted in a plasma concentration of 500 ± 180 nmol/L. Amiloride (100?mol/L) caused rightward shifts in concentration-response curves to phenylephrine in vitro. Long-term treatment with hydrochlorothiazide plus amiloride did not significantly increase the maximum response to phenylephrine (+13%). Reverse transcriptase polymerase chain reaction did not detect the NaCl cotransporter in mouse CC. Hydrochlorothiazide did not change Rho-kinase activity, whereas amiloride decreased it in vitro and ex vivo (approximately 18% and 24% respectively). A 40% decrease in Rock1 expression also was observed after long-term treatment with hydrochlorothiazide plus amiloride.Conclusion
Hydrochlorothiazide potentiates contraction of smooth muscle from mouse CC. These findings could explain why diuretics such as hydrochlorothiazide are associated with erectile dysfunction.
SUBMITTER: Gagliano-Juca T
PROVIDER: S-EPMC5005312 | biostudies-literature | 2016 Jun
REPOSITORIES: biostudies-literature
Sexual medicine 20160319 2
<h4>Introduction</h4>Hydrochlorothiazide has a negative influence on penile erection but little is known about the mechanism(s) involved.<h4>Aims</h4>To characterize the effects of this diuretic on mouse corpus cavernosum (CC) smooth muscle in vitro and ex vivo.<h4>Methods</h4>CC strips of C57BL/6 mice (12-16 weeks old) were mounted in organ baths containing Krebs-Henseleit solution and tissue reactivity was evaluated. Expression of genes encoding diuretic targets and enzymes involved in penile ...[more]