Thirteen women who were scheduled for hysterectomy volunteered for the study. Nine women had a levonorgestrel-releasing intrauterine contraceptive device inserted between 36 and 49 days prior to surgery and four women were on oral levonorgestrel treatment for 7 days prior to surgery. After the surgical removal of the uterus, samples of endometrial, myometrial, fallopian tube and fat tissue were obtained. Methods for measuring tissue concentrations of levonorgestrel were developed and the uptake of levonorgestrel by fat tissue in vitro was studied. The concentrations of levonorgestrel in myometrial, fallopian tube and fat tissue were all of the same order, of between 1 and 5 ng/g of wet weight of tissue, in both the intrauterine device group and the orally treated group. In the endometrium the levonorgestrel concentrations were many-fold higher in the intrauterine device group. The in vitro experiments showed a rapid uptake of levonorgestrel and an unsaturability of the fat tissue by the steroid at the concentrations used. The fat tissue concentrations of levonorgestrel correlated with the plasma concentrations.
The effect of lumbar extradural analgmig on intervillous blood flow (IBF) during labour was studied in 26 healthy parturients using an i. v. bolus injection of xenon-133. There was a 19% decrease (n.s.) in mean IBF in six parturients (non-extradural control group). Mean IBF increased by 37.5% when 0.25% bupivacaine 10 ml was used and by 35.2% when 2% 2-chloroprocaine 10 ml was used (n.».). When the two extradural groups were combined, the mean difference between IBFi and IBF2 was 45+ 112mlmin"' dl" 1. This increase is statistically significant (P< 0.05). The improvement in IBF after extradural block was considered to be a result of the decreased uterine vascular resistance, as no significant changes were observed in arterial pressure, utenne activity or uterine tone.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.