Modification of the effect of nifedipine in the pregnant rat myometrium: The influence of progesterone and terbutaline

Judit Hajagos-Tóth, George Falkay, Róbert Gáspár

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Aims: The aims of the study were to investigate the effects of nifedipine on potassium chloride (KCl)-evoked rat uterine contractions on different days of pregnancy in vitro, and the alterations in the effects of nifedipine on combination with terbutaline or progesterone. Main methods: In rat myometrial rings taken on different days of pregnancy, rhythmic contractions were evoked with KCl in an isolated organ bath. Key findings: The relaxing effect of nifedipine was most expressed in the 25 mM KCl-induced uterine contractions, reaching the maximum on the last day of pregnancy (day 22). This effect was decreased by progesterone pretreatment in vivo. Synergism was observed in the uterus-relaxing effect of nifedipine +terbutaline, though the extent of potentiation depended on the sequence of administration of the two compounds. When terbutaline was added first in a single dose, the maximal inhibitory effect of nifedipine was lower. This decrease in the inhibition was suspended by a Ca2+-poor buffer, indicating the role of Ca2+ channel activating effect of terbutaline. Significance: It is concluded that the uterus-relaxing effect of nifedipine is weakened by progesterone and may be enhanced by low concentrations of β-mimetics. However, the administration of terbutaline cannot precede the administration of nifedipine.

Original languageEnglish
Pages (from-to)568-572
Number of pages5
JournalLife Sciences
Volume85
Issue number15-16
DOIs
Publication statusPublished - Oct 7 2009

Fingerprint

Terbutaline
Myometrium
Nifedipine
Progesterone
Rats
Uterine Contraction
Pregnancy
Uterus
Potassium Chloride
Baths
Buffers

Keywords

  • β-adrenoreceptor agonists
  • Calcium channel blockers
  • Pregnancy
  • Progesterone
  • Uterine contractility

ASJC Scopus subject areas

  • Pharmacology, Toxicology and Pharmaceutics(all)
  • Biochemistry, Genetics and Molecular Biology(all)

Cite this

Modification of the effect of nifedipine in the pregnant rat myometrium : The influence of progesterone and terbutaline. / Hajagos-Tóth, Judit; Falkay, George; Gáspár, Róbert.

In: Life Sciences, Vol. 85, No. 15-16, 07.10.2009, p. 568-572.

Research output: Contribution to journalArticle

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