ABSTRACT
In vitro studies have established that tissue plasminogen activator (t-PA) expression can be stimulated directly by a plethora of chemical and environmental conditions. A number of hormones and growth factors, many reflecting the apparent biological roles that t-PA has been associated with in vivo, have been shown to directly regulate t-PA production. Studies of the process of ovulation originally suggested that breakdown of the follicle wall to release the mature oocyte was dependent on plasminogen activator activity. Tissue plasminogen activator has also been found in studies of neural development in the rat. In developing rat nervous tissue, high levels of t-PA mRNA were found at the cluster of floor plate cells lining the ventral midline of the ventricular cavity. The mouse promoter region is similar to that of the rat and contains some of the same consensus sequences. The studies defining t-PA gene regulation in the mouse were performed employing the F9 cells undergoing differentiation with retinoic acid and cAMP.
