Histochemical demonstration of lysosomal hydrolase activity in endometrial mononuclear cells. I. Normal endometrium

Interstitial cell reactivity for lysosomal hydrolases was demonstrated in 67 endometrial specimens with histochemical techniques. Cyclic changes in the number of reactive cells corresponded to the stage of the menstrual cycle. Techniques for galactosidase and glucuronidase showed increasing numbers of reactive cells through the late secretory stage. Staining for glucosaminidase and nonspecific esterase also increased in late secretory endometrium. In contrast, acid phophatase activity was biphasic, and that of leucine aminopeptidase remained relatively constant. Only minimal interstitial staining was seen in prepubertal and postmenopausal specimens.