Oxytocics reverse the tocolytic effect of glyceryl trinitrate on the human uterus

Mar 10, 2001BJOG : an international journal of obstetrics and gynaecology

Oxytocin-like drugs reverse the relaxing effect of glyceryl trinitrate on the human uterus

AI simplified

Circadian Biology on OpenScience ↗PubMed ↗DOI ↗

Abstract

Glyceryl trinitrate reduced the amplitude and frequency of spontaneous uterine contractions in a concentration-dependent manner, with complete inhibition occurring at concentrations ranging from 44-705 microM.

The sensitivity of myometrial strips to glyceryl trinitrate varied significantly among specimens.
Inhibition of uterine contractions by glyceryl trinitrate was reversed by oxytocin, ergometrine, and prostaglandin F2alpha.
Oxytocin at 20 mU/mL and ergometrine and prostaglandin F2alpha at 6.15 microM restored uterine contractility to levels higher than untreated strips.
Glyceryl trinitrate is identified as a potent uterine relaxant in vitro.

AI simplified

OBJECTIVES: To investigate the effect of glyceryl trinitrate on isolated human pregnant uterine strips and whether the uterine relaxation induced by glyceryl trinitrate could be reversed by oxytocics used in current clinical practice.

DESIGN: In vitro pharmacological study.

SETTING: Department of Obstetrics & Gynaecology, National University of Singapore, National University Hospital.

PARTICIPANTS: Eighteen women who delivered by caesarean section at term.

METHODS: Myometrial strips were preloaded with an initial tension of 1.5g in organ baths containing Krebs-Henseleit solution which was aerated with oxygen in 5% carbon dioxide and maintained at 37 degrees C, pH 7.4. The effect of glyceryl trinitrate was studied in strips displaying regular spontaneous contractions. The ability of oxytocin, ergometrine or prostaglandin F2alpha to stimulate uterine contractions was assessed in strips where uterine activity was significantly inhibited by glyceryl trinitrate.

RESULTS: Glyceryl trinitrate reduced the amplitude and frequency of spontaneous uterine contractions in a concentration-dependent manner, although the sensitivity of the myometrial strips varied considerably from one specimen to another. The concentration of glyceryl trinitrate producing complete inhibition of myometrial contractions ranged from 44-705 microM. In the presence of glyceryl trinitrate which markedly depressed spontaneous contractions, oxytocin (20 mU/mL), ergometrine (6.15 microM) and prostaglandin F2alpha (6.15 microM) were capable of reversing the uterine activity to either higher than or the untreated level of contractility.

CONCLUSIONS: This study demonstrates that glyceryl trinitrate is a potent uterine relaxant in vitro and that the tocolytic effect could be reversed with ease by oxytocics.

Full Text

Full text is available at the source.

View full text ↗

Oxytocics reverse the tocolytic effect of glyceryl trinitrate on the human uterus

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief