Inhibition of contractile responses of human myometrium and intramyometrial arteries by potassium channel openers.

OBJECTIVES

The effects of cromakalim and pinacidil on the contractile activity of the isolated human myometrium and intramyometrial arteries were studied.

MATERIAL AND METHOD

Myometrial strips and pieces of uterine arteries were obtained from women undergoing hysterectomy. Contractions were recorded under isometric conditions.

RESULTS

Both compounds (10(-9) M-5 x 10(-6) M) inhibited the spontaneous activity of the myometrium and vasopressin induced contractions of myometrium and intramyometrial arteries. There was no statistically significant difference in the responses of both tissues to cromakalim or pinacidil. Both compounds reduced responses of myometrium and intramyometrial arteries to low concentration of K+ (< 40 mM) but did not decrease contractions induced by 40 mM and 80 mM.

CONCLUSION

The combined effect on the uterus and intrauterine vasculature would suggest a potential in the use of cromakalim or pinacidil for the treatment of dysmenorrhea.