Human Reproduction, Vol. 18, No. 1, 148-151,
January 2003
© 2003 European Society of Human Reproduction and Embryology
Effects of L-arginine and sodium nitroprusside on the spontaneous contractility of human non-pregnant uterus
1 Department of Obstetrics and Gynaecology and 2 Laboratory of Pharmacology, Grenoble University Hospital, Grenoble, BP219, 38043 Grenoble, Cedex 9 and 3 Department of obstetrics and Gynaecology and Reproductive Endocrinology, Hospital Antoine Béclère, Clamart, France 4 To whom correspondence should be addressed. e-mail: PHoffmann{at}chu-grenoble.fr
BACKGROUND: The aim of this study was to investigate, in isolated human non-gravid myometrium, the involvement of the cyclic guanosine monophosphate (cGMP) pathway in nitric oxide (NO) induced relaxation. METHODS: Strips of human myometrium from hysterectomized women were suspended in organ baths for recording of isometric tension. Cumulative concentration-response curves for L-arginine and sodium nitroprusside were performed in the presence of methylene blue (10 µmol/l) or vehicle (control). The effect of increasing concentrations of 8-bromo-cGMP on uterine spontaneous contraction was also studied. RESULTS: L-arginine and sodium nitroprusside induced a concentration-dependent decrease in the amplitude of the myometrial spontaneous contractions. Pre-treatment with methylene blue enhanced the inhibitory effect of L-arginine and sodium nitroprusside on myometrial spontaneous contractions. In addition, 8-bromo-cGMP had no effect on spontaneous contractions in human myometrium. CONCLUSIONS: These data provide evidence that L-arginine and sodium nitroprusside inhibit the spontaneous contractions of the non-pregnant human uterus through a cGMP independent pathway.
Key words: cGMP pathway/human non-pregnant uterus/methylene blue/nitric oxide