The effects of nitric oxide on the contractility of isolated uterine and aortic rings from pregnant rats

T. Okawa, A. S. Syal, Y. P. Vedernikov, G. R. Saade, K. Chwalisz, R. E. Garfield

Research output: Contribution to journalArticlepeer-review

18 Scopus citations


OBJECTIVE: The object was to compare the effects of nitric oxide on isolated uterus and aorta of pregnant rats. STUDY DESIGN: Rings of uterus and thoracic aorta without endothelium from Sprague-Dawley rats at mid and late gestation were used for isometric tension recording. The concentration- response curve for diethylamine/nitric oxide was studied in the presence or absence of oxyhemoglobin (10-5 mol/L), or oxyhemoglobin was added after the response to diethylamine/nitric oxide. RESULTS: Diethylamine/nitric oxide concentration dependently inhibited uterine contractions, and the effect was attenuated by previous treatment with oxyhemoglobin at mid gestation (n = 8). The effects were negligible at late gestation (n = 8). The relaxation of aortic rings by diethylamine/nitric oxide and its attenuation by previous treatment with oxyhemoglobin were similar at mid (n = 6) and late (n = 6) gestation. The sensitivity of aortic rings to diethylamine/nitric oxide is significantly higher than that of uterine rings. Oxyhemoglobin partly restored inhibited diethylamine/nitric oxide phenylephrine tension in aortic rings and had no effect on diethylamine/nitric oxide-inhibited uterine rings. CONCLUSIONS: Uterine smooth muscle is less sensitive to nitric oxide than is aortic smooth muscle. Nitric oxide sensitivity of rat uterus but not aorta decreases toward term.

Original languageEnglish (US)
Pages (from-to)721-726
Number of pages6
JournalAmerican journal of obstetrics and gynecology
Issue number3 I
StatePublished - 1998
Externally publishedYes


  • Aorta
  • Myometrium
  • Nitric oxide
  • Oxyhemoglobin
  • Pregnancy

ASJC Scopus subject areas

  • Obstetrics and Gynecology


Dive into the research topics of 'The effects of nitric oxide on the contractility of isolated uterine and aortic rings from pregnant rats'. Together they form a unique fingerprint.

Cite this