Halothane, enflurane, methoxyflurane, and isolated human uterine muscle

The depressant effects of halothane, enflurane and methoxyflurane at 0.5, 1.0 and 1.5 MAC on isolated human gravid uterine muscle have been studied. The muscle samples were obtained from women undergoing caesarean section at between 38 and 41 weeks gestation. All three agents produced depression of uterine muscle contractility and of contraction frequency. There were no significant differences between the degree of depression of the uterine muscle at equipotent concentrations of the three volatile agents. Differing concentrations of the same agent over the range 0.5 to 1.5 MAC produced no significant change in the uterine muscle depression.