Although it is well known that progesterone alters uterine contractility and plays an important role in maintenance of pregnancy, the biochemical mechanisms by which progesterone alters uterine contractility in human gestation are less clear. In this investigation we sought to identify progesterone-induced adaptations in human myometrial smooth muscle cells that may alter Ca2+signaling in respo...

BACKGROUND Deciding whether to treat postmenopausal women suffering from climacteric symptoms with Continuous Combined Hormone Replacement Therapy (CCHRT) has become increasingly difficult after the release of the Women's Health Initiative results. As a result, development of alternatives to CCHRT is required. Tibolone, which is a synthetic steroid that has estrogenic, progestogenic and androge...

BACKGROUND Recently published data suggest that hormone replacement therapy (HRT) may increase cardiovascular risk during the early months of therapy. Activation of the immune system is known to be involved in several types of cardiovascular disease. In this cross-sectional study, serum C3, C4, IgG and IgM levels were evaluated in healthy post-menopausal women receiving two different short-term...

Most individuals latently infected with Mycobacterium tuberculosis (M.tb) contain the infection by a balance of effector and regulatory immune responses. This balance can be influenced by steroid hormones such as glucocorticoids. The widely used contraceptive medroxyprogesterone acetate (MPA) possesses glucocorticoid activity. We investigated the effect of this hormone on immune responses to BC...

BACKGROUND Hormone therapy (HT) after the menopause is associated with increased risk of venous thromboembolism (VTE). Tibolone has pharmacodynamic properties different from other hormone preparations. We compared the effect of a combined HT and tibolone on the inhibition of haemostasis. METHODS Thirty-eight post-menopausal women were randomly assigned to 1.25 or 2.5 mg per day of tibolone or...

BACKGROUND Inflammation plays an important role in the response to endoluminal vascular injury. Estrogen (17beta-estradiol, E2) inhibits neointima formation in animal models, and the progestin medroxyprogesterone acetate (MPA) blocks this effect. This study tested the hypothesis that E2 inhibits the migration of inflammatory cells, particularly granulocytes, into the rat carotid arteries after ...

The endothelial effects of progestogens are poorly investigated. Actin remodeling and cell movement are fundamental for endothelial function and are controlled by the actin-binding protein moesin. In this work, we studied the effects of progesterone and medroxyprogesterone acetate (MPA) on actin remodeling, moesin activation and cell movement in human endothelial cells. Our findings show that p...

Fomin, Victor P., Blair E. Cox, and R. Ann Word. Effect of progesterone on intracellular Ca21 homeostasis in human myometrial smooth muscle cells. Am. J. Physiol. 276 (Cell Physiol. 45): C379–C385, 1999.—Although it is well known that progesterone alters uterine contractility and plays an important role in maintenance of pregnancy, the biochemical mechanisms by which progesterone alters uterine...

Increased proliferation and breast cancer risk has been observed in postmenopausal women receiving estrogen (E) + progestin hormone replacement therapy (HRT). Progestin action is mediated through two progesterone receptor (PR) isoforms, PRA and PRB, with unique transcriptional activity and function. The current study examines hormonal regulation of PR isoforms in the normal postmenopausal human...

In endometrial cancer, decreased expression of progesterone receptor (PR) isotypes A and B (PRA and PRB) is a feature of poorly differentiated tumours. In distant metastases, PRB is the predominantly expressed isotype and endometrial cancer cells that express PRB have been observed to be more invasive. Furthermore, PRB-associated in vitro invasion is markedly inhibited by progestagens. In the p...