Because the levels of PGI synthase are comparable in the two muscle layers and do not vary with steroid treatments, it is tempting to conclude that the regulation of PGI2 production in the myometrium is regulated through the expression of PGHS-2. It is also interesting if not intriguing to see that the selective PGHS-2 inhibitor CGP 28238 not only inhibited the converting activity but also reduced the overexpression of PGHS-2 mRNA in response to PMA. Selective stimulation of PGHS mRNA and protein levels by PGE2 has been demonstrated in osteoclastic MC3T3-E1 and bone cells. canadian health and care mall
High amounts of PGs are produced by the endometrium and other intrauterine tissues during pregnancy and may influence myometrial contractility. However, present and previous data from our laboratory indicate the presence of endogenous PG regulatory pathways within the myometrium. An imbalance in the production of PG, particularly PGI2, may lead to the modification of uterine reactivity to exogenous regulators of uterine contractility. This concept is supported by our previous observation that the longitudinal layer, which produces large amounts of PGI2, concurrently expresses less connexin-43.