EXPRESSION OF PLASMINOGEN-ACTIVATOR AND INHIBITOR, UROKINASE RECEPTORAND INHIBIN SUBUNITS IN RHESUS-MONKEY TESTES

The expression and localization of mRNAs for tissue plasminogen activa tor (tPA), urokinase PA (uPA), uPA receptor (uPAR) and inhibin subunit s, alpha, beta(A) and beta(B) in monkey testes was investigated. Using in-situ hybridization with digoxigenin-labelled cRNA probes (dig-cRNA ), we demonstrated that tPA and plasminogen activator inhibitor type 1 (PAI-1) were expressed in testes of both immature and mature rhesus m onkeys. tPA mRNA was localized predominantly in Sertoli cells. Express ion level was low in immature testis, increased dramatically in the ad ult and varied with seminiferous cycle. PAI-1 mRNA was localized mainl y in germ cells except late spermatids. uPA mRNA was expressed stage-s pecifically in Sertoli cells of adult testis. uPA receptor mRNA was lo calized in germ cells of mature testis but not in spermatogonia or lat e spermatids. Assayed by fibrin overlay technique, PA activity in cond itioned media of purified Sertoli cells (Sc) was negligible, PA activi ty in media obtained from co-cultured Sertoli and Leydig cells (LS), h owever, was significantly increased, although Leydig cells alone were not capable of producing any PA activity. Addition of follicle stimula ting hormone (FSH) to the incubation medium remarkably increased PA se cretion in both Sc and LS cultures. Human chorionic gonadotrophin (HCG ) had no significant effect on PA activity in the Sc culture but drama tically stimulated PA activity in the co-culture system. Dihydrotestos terone (DHT) did not mimic the effect of HCG. PAI-1 activity was secre ted mainly by germ cells and did not differ between the two culture sy stems. FSH and forskolin inhibited PAI-1 secretion. Inhibin alpha, bet a(A) and beta(B) subunit mRNAs were localized in Sertoli cells of adul t monkey testes, with no obvious difference in the expression levels. These data suggest that PA/PAI-1 and other related factors are express ed in rhesus monkey testis under the control of various hormones, semi niferous cycle and cell-cell interactions through paracrine or autocri ne regulation. Locally generated fibrinolysis may play an important ro le in the process of spermatogenesis.