Uterine Muscle Relaxation Research Articles

Role of myometrial constriction in the induction of wavy ribs in rat fetuses.

Furosemide, a loop diuretic, was orally administered to pregnant Crj: CD (SD) rats at a dose of 300 mg/kg once on day 16 of gestation. Cartilage bone double staining of day 17 fetuses revealed a delay in ossification. Characteristic rib deformities were not seen until day 18 of gestation. Concomitant with this observation were reductions in the amount of amniotic fluid, compared to controls, on day 18 of gestation and thereafter. When isoxsuprine HCl (2 mg/kg, b.i.d.), a uterine muscle relaxant, was additionally injected ip to pregnant rats on days 17-19 of gestation, the incidence of wavy ribs was significantly (P less than or equal to .05) less than that seen after treatment with furosemide alone. These observations indicate that the myometrial constriction plays a significant role in the induction of furosemide-induced wavy ribs.

Terbutaline in diagnosis of interstitial fallopian tube obstruction.

Effectiveness of terbutaline, a potent uterine muscle relaxant, for differentiation of temporary and anatomic interstitial fallopian tube obstruction (IFTO) at hysterosalpingography (HSG) was explored. In 43 IFTO evaluated, HSG after terbutaline showed patency in only one of 16 tubes in which IFTO was caused by spasm or other temporary cause. We conclude that terbutaline is not helpful in differentiating temporary from anatomic tubal obstruction during HSG.

Buphenine and threatened abortion

One hundred and seventy patients with threatened abortion have been studied in two groups. Group 1 of eighty-five patients were treated with the uterine muscle relaxant, buphenine hydrochloride. The second group of eighty-five patients were given placebo. Pregnancy continuation was 90.6% in group 1 and 62.3% in group 2. Only three of 22 patients with history of recurrent abortion using buphenine aborted.

Influence of pregnancy and sex steroids on concentration, motor effect and receptor binding of VIP in the rabbit female genital tract.

The influence of sex steroid and pregnancy on the tissue concentration, uterine motor effect and receptor binding of VIP has been studied in the female genital tract of pregnant rabbits and oophorectomized rabbits during progesterone and/or oestrogen substitution. The concentration of immunoreactive VIP was high in the vagina and cervix, and lower in the uterine body of both pregnant and non-pregnant rabbits. A significant decrease in the VIP concentration (pmol/g wet weight) of the uterine body was observed toward term of pregnancy. The total uterine content of VIP, however, seems unchanged. Treatment of oophorectomized rabbits with ovarian steroids had no effect on the VIP concentration. The sensitivity for and potency of VIP on the relaxation of uterine muscle was significantly higher in oophorectomized rabbits treated with a combination of progesterone and oestrogen than in control rabbits. No difference was observed between non-pregnant and pregnant rabbits. The degradation and binding affinity for 125I-labelled VIP was highest in oophorectomized rabbits substituted with both oestrogen and progesterone. In the pregnant rabbits, the amount of receptors was decreased near term. In conclusion, sex steroids are able to influence the motor effect of VIP at the receptor level, but have no effect on the VIP concentration in the female genital tract.