Author/Editor		Novak-Antolič, Ž
Title		Študij mediatorskih sistemov v humanem miometriju
Type		monografija
Place		Ljubljana
Publisher		Medicinska fakulteta
Publication year		1989
Volume		str. 91
Language		slo
Abstract		The nature of the enormous increase of myometrial responsiveness observed at parturition compared to the low responsiveness during pregnancy is still poorly understood. The changes involved with the phenomenon occur at several levels: in the ratios of circulating estrogen/progesterone levels and in the concentration of different hormone receptors on the myometrial cell membrane. Furthermore, the morphologic changes occur within the myocardial cells and in uterine innervation. Compared to other systems, there are relatively few data in the literature on the detailed role and behaviour of the components of the cholinergic system in the pregnant and parturient human uterus. Consequently, we decided to evaluate two components of the cholinergic system in the control group, where the labour process has not yet started, and in the study group, where labour was well advanced. In both groups either elective or urgent cesarean sections were performed, respectively, for maternal and/or fetal indications. Activity of cholinesterases in myometrium was significantly higher in the study group. In contrast to some previous reports, only traces of activity of cholineacetyltransferase were found in the myometrium of either group. The cholinergic innervation may still be functioning, but the muscle/nerve mass-ratio is quite high in the pregnant myometrium near term and for such a dilute enzyme the assay method might not be sensitive enough. Cytochemically, the reaction products of the acetylcholinesterase and butyrylcholinesterase activities were found in the cell membrane, nuclear membrane and sarcoplasmic reticulum. No differences between the groups were found as far as subcellular localization of the reaction products is concerned. (Abstract truncated at 2000 characters).
Descriptors		MYOMETRIUM ACETYLCHOLINESTERASE BUTYRYLCHOLINESTERASE LABOR UTERINE CONTRACTION HISTOCYTOCHEMISTRY PLACENTA PREGNANCY