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Inhibition by sildenafil of contractility of isolated non-pregnant human myometrium.

Winston AB, Vazhudhi K, Sen S, Thomas E, Benjamin S, Peedicayil J - J Pharmacol Pharmacother (2015 Jul-Sep)

Bottom Line: To investigate the ability of sildenafil to inhibit the contractility of isolated non pregnant human myometrium.The inhibitory effect of three concentrations (3, 10, and 30 µM) of sildenafil on 55 mM KCl-induced contractility of isolated non-pregnant human myometrium was studied.The results suggest that sildenafil does so by opening BKCa channels.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology and Clinical Pharmacology, Christian Medical College, Vellore, Tamil Nadu, India.

ABSTRACT

Objective: To investigate the ability of sildenafil to inhibit the contractility of isolated non pregnant human myometrium.

Materials and methods: The inhibitory effect of three concentrations (3, 10, and 30 µM) of sildenafil on 55 mM KCl-induced contractility of isolated non-pregnant human myometrium was studied. The ability of the guanylyl cyclase inhibitor ODQ (10 µM), the adenylyl cyclase inhibitor MDL-12,330A (10 µM), the non-specific potassium channel blocker TEA (2 mM), and the calcium-sensitive potassium (BKCa) channel blocker iberiotoxin (100 nM) to reverse the inhibition of 10 µM sildenafil on KCl-induced myometrial contractility was also studied.

Results: Sildenafil produced a concentration-dependent inhibition of KCl-induced myometrial contractility that was statistically significant at all three concentrations of sildenafil used. The inhibition by 10 µM sildenafil of KCl-induced myometrial contractility was not reversed by the concurrent administration of ODQ or MDL-12,330A. The inhibition of 10 µM sildenafil of myometrial contractility was partially reversed by concurrent administration of TEA and totally and significantly reversed by the concurrent administration of iberiotoxin.

Conclusions: These results suggest that sildenafil inhibits the contractility of isolated non-pregnant human myometrium. The results suggest that sildenafil does so by opening BKCa channels.

No MeSH data available.


Sample traces from the second study phase: (a) Contractile effect of 55 mM KCl before (left side) and after (right side) addition of 10 µM sildenafil. (b) Contractile effect of 55 mM KCl before (left side) and after (right side) addition of 100 nM iberiotoxin and 10 μM sildenafil
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Figure 2: Sample traces from the second study phase: (a) Contractile effect of 55 mM KCl before (left side) and after (right side) addition of 10 µM sildenafil. (b) Contractile effect of 55 mM KCl before (left side) and after (right side) addition of 100 nM iberiotoxin and 10 μM sildenafil

Mentions: The results of the effect of DMSO and sildenafil on KCl-induced contractility of isolated non-pregnant human myometrium are shown in Table 1. As shown, DMSO did not significantly inhibit KCl-induced myometrial contractility, whereas sildenafil produced a concentration-dependent inhibitory effect of KCl-induced myometrial contractility that was statistically significant at all three concentrations of sildenafil used. The results of the effects of the reversal agents on sildenafil-induced myometrial relaxation are shown in Tables 2 and 3. ODQ and MDL-12,330 A were not found to reverse the inhibitory effect of sildenafil on KCl-induced myometrial contractility. TEA partially reversed the inhibitory effect of sildenafil on myometrial contractility. Iberiotoxin completely and significantly reversed the inhibitory effect of sildenafil on myometrial contractility. Sample tracings of the effect of sildenafil on KCl-induced myometrial contractility and the effects of the reversal agents on 10 μM sildenafil's inhibition of KCl-induced myometrial contractility are shown in Figures 1 and 2.


Inhibition by sildenafil of contractility of isolated non-pregnant human myometrium.

Winston AB, Vazhudhi K, Sen S, Thomas E, Benjamin S, Peedicayil J - J Pharmacol Pharmacother (2015 Jul-Sep)

Sample traces from the second study phase: (a) Contractile effect of 55 mM KCl before (left side) and after (right side) addition of 10 µM sildenafil. (b) Contractile effect of 55 mM KCl before (left side) and after (right side) addition of 100 nM iberiotoxin and 10 μM sildenafil
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4544134&req=5

Figure 2: Sample traces from the second study phase: (a) Contractile effect of 55 mM KCl before (left side) and after (right side) addition of 10 µM sildenafil. (b) Contractile effect of 55 mM KCl before (left side) and after (right side) addition of 100 nM iberiotoxin and 10 μM sildenafil
Mentions: The results of the effect of DMSO and sildenafil on KCl-induced contractility of isolated non-pregnant human myometrium are shown in Table 1. As shown, DMSO did not significantly inhibit KCl-induced myometrial contractility, whereas sildenafil produced a concentration-dependent inhibitory effect of KCl-induced myometrial contractility that was statistically significant at all three concentrations of sildenafil used. The results of the effects of the reversal agents on sildenafil-induced myometrial relaxation are shown in Tables 2 and 3. ODQ and MDL-12,330 A were not found to reverse the inhibitory effect of sildenafil on KCl-induced myometrial contractility. TEA partially reversed the inhibitory effect of sildenafil on myometrial contractility. Iberiotoxin completely and significantly reversed the inhibitory effect of sildenafil on myometrial contractility. Sample tracings of the effect of sildenafil on KCl-induced myometrial contractility and the effects of the reversal agents on 10 μM sildenafil's inhibition of KCl-induced myometrial contractility are shown in Figures 1 and 2.

Bottom Line: To investigate the ability of sildenafil to inhibit the contractility of isolated non pregnant human myometrium.The inhibitory effect of three concentrations (3, 10, and 30 µM) of sildenafil on 55 mM KCl-induced contractility of isolated non-pregnant human myometrium was studied.The results suggest that sildenafil does so by opening BKCa channels.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology and Clinical Pharmacology, Christian Medical College, Vellore, Tamil Nadu, India.

ABSTRACT

Objective: To investigate the ability of sildenafil to inhibit the contractility of isolated non pregnant human myometrium.

Materials and methods: The inhibitory effect of three concentrations (3, 10, and 30 µM) of sildenafil on 55 mM KCl-induced contractility of isolated non-pregnant human myometrium was studied. The ability of the guanylyl cyclase inhibitor ODQ (10 µM), the adenylyl cyclase inhibitor MDL-12,330A (10 µM), the non-specific potassium channel blocker TEA (2 mM), and the calcium-sensitive potassium (BKCa) channel blocker iberiotoxin (100 nM) to reverse the inhibition of 10 µM sildenafil on KCl-induced myometrial contractility was also studied.

Results: Sildenafil produced a concentration-dependent inhibition of KCl-induced myometrial contractility that was statistically significant at all three concentrations of sildenafil used. The inhibition by 10 µM sildenafil of KCl-induced myometrial contractility was not reversed by the concurrent administration of ODQ or MDL-12,330A. The inhibition of 10 µM sildenafil of myometrial contractility was partially reversed by concurrent administration of TEA and totally and significantly reversed by the concurrent administration of iberiotoxin.

Conclusions: These results suggest that sildenafil inhibits the contractility of isolated non-pregnant human myometrium. The results suggest that sildenafil does so by opening BKCa channels.

No MeSH data available.