It is commonly thought that uterine leiomyomas result from hyperstimulation of myometrium by ovarian hormones. Some observations suggest that cytokines and growth factors are intermediate elements through which the ovarian hormones may exert their growth-stimulatory effects on leiomyomas. Human myometrium and uterine leiomyomas of various weights were homogenised and extracted with 1 M acetic a...

Human labour is associated with increased prostaglandin synthesis within the uterus. The aim of this study was to examine the expression of the type-IV cytosolic phospholipase A2 (cPLA2-IV) and the type IIA secretory phospholipase A2 (sPLA2-IIA) in myometrium in association with labour onset at term and preterm deliveries. These enzymes are important for the release of the prostaglandin precurs...

Telocytes (TCs) have been described in various organs and species (www.telocytes.com) as cells with telopodes (Tps) - very long cellular extensions with an alternation of thin segments (podomers) and dilated portions (podoms). We examined TCs using electron microscopy (EM), immunohistochemistry (IHC), immunofluorescence (IF), time-lapse videomicroscopy and whole-cell patch voltage clamp. EM sho...

There is evidence for hormonal receptor desensitisation in human myometrium, but little is known about the mechanisms involved in the loss of myometrial response to agonists such as beta(2)-adrenergic agonists, prostaglandin gamma and oxytocin. It is well known that the receptors for these hormones are coupled to G-proteins. The first step of receptor desensitisation is the phosphorylation of a...

Endometrial cancer is the most common gynecological malignancy in Croatia. The aim of this study was to determine the immunohistochemical expression of estrogen receptors (ER) and progesterone receptors (PGR) in cancer cells and in the myometrium and to correlate it with prognostic factors of endometrial carcinoma. ER positivity in carcinoma cell nuclei was found in 42 cases (73.7%) and PGR pos...

Activation of voltage-dependent Ca2+ channels by high K+ (40 mM) increased the cytosolic Ca2+ level ([Ca2+]i) (estimated by fura-PE3 fluorescence ratio) and force in myometrium isolated from pregnant (21 days after gestation) and non-pregnant (estrus) rats. 12-Deoxyphorbol 13-isobutyrate (DPB, 1 mM) decreased the high (K+)-stimulated [Ca2+]i and force in a concentration-dependent manner. The in...

DNA fragmentation factors 40 and 45 (DFF40 and DFF45) and B-cell lymphoma 2 (Bcl-2) 16 expression were evaluated in the normal human endometrium and myometrium. DFF40, DFF45, 17 and Bcl-2 expression was assessed via immunohistochemistry in the proliferative, secretory, and 18 atrophic endometrium and myometrium collected postmenopausally and premenopausally during 19 the proliferative and secre...

This study aimed to compare vascular parameters between fibroid and myometrium. From 10 uteri, specimens were taken from small fibroids (<0.5 cm), from the inner and outer parts of large fibroids (>3 cm), and from myometrium. Antibodies to endothelial cell markers CD31, CD34, factor VIII-related antigen (FVIII), and Ulex europaeus lectin were used in routine immuno- and lectin chemistry protoco...

The pseudocapsule surrounding fibroids consists of compressed myometrium containing nerves and blood vessels that continue into adjacent myometrium. Oxytocin (OXT) is thought to affect wound healing after myomectomy. We determined the presence of OXT and protein gene product 9.5 (PGP9.5) immunoreactive nerve fibers in pseudocapsule compared to adjacent myometrium. Samples (N=106) of pseudocapsu...

The ideal agent for prevention and treatment of uterine abnormal contractility has not been found. The polyphenol resveratrol possesses a wide spectrum of pharmacologic properties, but its influence on the contractility of human myometrium is not defined. The present study evaluated the effect of resveratrol on the oxytocin-induced contractions of human term pregnant myometrium in vitro and the...