Significance of a new isovolumetric technique for the study of the myometrial dynamics in vitro.

: Above usual values for active tension are measured in 10 uterine horns of rat under electric stimulation through an original isovolumetric technique. At the maximum length increase attained were 1.79 +/- 0.2 kg/cm2, with passive tension from 9--10% total tension. These values are within the range for other smooth and striated muscles. The isometric techniques efficacy to record total uterine tension, as well as the application of isometric activity to the analyse of uterine dynamics are discussed.