Influence of progesterone on myometrial contractility in pregnant mice treated with lipopolysaccharide

  • Hiroshi Anbe
  • , Toshiaki Okawa
  • , Noboru Sugawara
  • , Hidenori Takahashi
  • , Akira Sato
  • , Yuri P. Vedernikov
  • , George R. Saade
  • , Robert E. Garfield

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

Aim: To evaluate the effect of progesterone on interleukin (IL)-6, prostaglandin (PG) E2 and nitric oxide (NO) metabolite (NOx) production and contractile activity by NO in pregnant mice treated with lipopolysaccharide (LPS). Methods: Pregnant C57BL mice on day 14 of gestation were killed 6 h after i.p. injection of LPS (400 μg/kg) or vehicle. Progesterone (2 mg) was subcutaneously injected 2 h before LPS treatment. Uterine rings were equilibrated in Krebs-Henseleit solution (37°C) bubbled with 20% O2 and 5% CO2 (pH 7.4) for sampling and isometric tension recording. IL-6, PGE2 and NOx productions were measured from the bathing solution. Changes in spontaneous contractile activity in response to cumulative concentrations of l-arginine, diethylamine/nitric oxide (DEA/NO, the NO donor), and 8-bromo-cGMP (8-br-cGMP) were compared. Integral contractile activity over 10 min after each concentration was calculated and expressed as percentage change from basal activity. Statistical analyses were performed using one-way anova followed by Dunnett's test (significance was defined as P < 0.05). Results: Interleukin-6 (34.7 ± 6.0 pg/g tissue), PGE2 (66.8 ± 6.7 pg/g tissue) and NOx (51.0 ± 5.4 pmol/2 mL/g wet tissue) production were significantly stimulated by LPS treatment (138.2 ± 23.2, 147.0 ± 29.0, 98.6 ± 16.2, respectively; P < 0.05). l-arginine, DEA/NO and 8-br-cGMP concentration-dependently inhibited spontaneous contractions in uterine rings both in LPS-treated and -untreated animals. Treatment with LPS significantly attenuated the maximal inhibition induced by l-arginine, DEA/NO and 8-br-cGMP in uterine rings from pregnant mice. Progesterone significantly decreased the levels of IL-6 production (74.9 ± 12.1, P < 0.05), but not PGE2 and NOx production, and contractile responses by l-arginine, DEA/NO and 8-br-cGMP. Conclusions: The administration of LPS is associated with increases in IL-6, PGE2 and NO, and these increases may or may not have a role to play in LPS-induced preterm labor. Progesterone reduced the LPS-induced increase in IL-6 production and this may be one of the ways that progesterone reduces the risk of preterm labor.

Original languageEnglish (US)
Pages (from-to)765-771
Number of pages7
JournalJournal of Obstetrics and Gynaecology Research
Volume33
Issue number6
DOIs
StatePublished - Dec 2007

Keywords

  • Contractility
  • IL-6
  • Lipopolysaccharide
  • Myometrium
  • Nitric oxide
  • PGE

ASJC Scopus subject areas

  • Obstetrics and Gynecology

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