Estrone sulfatase activity in uterine leiomyoma and overlying endometrial tissue

ABSTRACT

Estrone sulfatase activity was measured in endometrial, leiomyoma and myometrial tissues of the same uterus in 10 patients with uterine leiomyoma who did hysterectomy in the period between December 1991 and December 1992. Four samples were obtained from each uterus for analysis, the first from normal myometrium, the second from the leiomyoma, the third from the endometrium overlying normal myometrium, and the fourth from the endometrium overlying the leiomyoma. The samples were incubated with 200 um 4-methylumbeliferone sulfate for 30 minutes then the liberated methylumbeliferone was measured fluorometrically. The average value of estrone sulfatase was 0.799 nmol/hour/mg in normal myometrium, 0.711 nmol/hour/mg in leiomyoma, 2.255 nmol/hour/mg in endometrium over normal myometrium and 2.74 nmol/hour/mg in endometrium over leiomyoma. The estrone sulfatase was significantly higher [p <0.001] in endometrium overlying leiomyoma than in endometrium overlying normal myometrium. Estrone sulfatase activity in normal endometrium was significantly higher compared with that in leiomyoma or myometrial tissues. It was also found that estrone sulfatase activity was significantly different [p <0.02] between leiomyoma and normal myometrial tissues. These results suggested that an increase in estrone sulfatase activity in the local endometrium and not in leiomyoma is what may be related to enlargement of uterine leiomyoma