title: Inhibition by sildenafil of contractility of isolated non-pregnant human myometrium.
abstract: OBJECTIVE
  To investigate the ability of sildenafil to inhibit the contractility of isolated non pregnant human myometrium.
  
  
  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.
authors: Department of Pharmacology and Clinical Pharmacology, Christian Medical College, Vellore, Tamil Nadu, India.
authors: Aruldhas Blessed
authors: AB
authors: Winston
authors: Department of Pharmacology and Clinical Pharmacology, Christian Medical College, Vellore, Tamil Nadu, India.
authors: Kaysina
authors: K
authors: Vazhudhi
authors: Department of Pharmacology and Clinical Pharmacology, Christian Medical College, Vellore, Tamil Nadu, India.
authors: Sumalya
authors: S
authors: Sen
authors: Department of Obstetrics and Gynaecology, Christian Medical College, Vellore, Tamil Nadu, India.
authors: Elsy
authors: E
authors: Thomas
authors: Department of Obstetrics and Gynaecology, Christian Medical College, Vellore, Tamil Nadu, India.
authors: Santhosh
authors: S
authors: Benjamin
authors: Department of Pharmacology and Clinical Pharmacology, Christian Medical College, Vellore, Tamil Nadu, India.
authors: Jacob
authors: J
authors: Peedicayil
keywords: Contractility; myometrium; non-pregnant; sildenafil