The response to mechanical distension of the non-pregnant human uterus in vivo

Abstract: The ability of the uterus to contract in response to mechanical distension has been utilized in the development of a method, hysterometry, for the quantification of hormonal and pharmacological effects on the human myometrium in vivo. The method has been built up with due consideration for laws from mechanics of materials and hydrodynamics. By applying mathematical theorems and accepting certain approximations, the basic results of recordings of intrauterine pressure are transformed inte wall tension, allowing for the size of the uterus. The equivalent of an elasticity modulus in the myometrium has been used as a synthetic discriminator (without any real physiologic correlation) for the evaluation of hormonal and pharmacological effects.Hysterometry har been used for the evaluation of uterine tonicity during the menstrual cycle. It was demonstrated that uterine tonicity is higher in the proliferative than in the secretory phase. The uterine tonicity correlated well with the concentrations in serum of estradiol and progesterone at the time of the examination.Hysterometry has also been used for the evaluation of effects of inhibitors of prostaglandin synthesis (Naproxen Sodium and Naproxen acid) and of a selective beta-2-receptor stimulator (Salbutamol) upon the uterus in women with primary dysmenorrhea. It was shown that uterine tonicity was high on the first day of menstruation in untreated or placebo-treated dysmenorrheic women. Administration of inhibitors of prostaglandin synthesis or beta-2-receptor stimulating agents markedly decreased the uterine tonicity and relieved the menstrual pain.