Endometrial lysosomal enzyme activity in ovulatory dysfunctional uterine bleeding, IUCD users and post-partum women

The aim of this study was to evaluate the role of lysosomal enzymes in excessively heavy menstruation by comparing women with menorrhagia due to dysfunctional bleeding or intrauterine contraceptive device (IUCD) use with those with normal menstrual periods or with amenorrhoea associated with breastfeeding. This was a prospective cohort investigation of the activity of four endometrial lysosomal enzymes in three contrasting groups: (i) women with ovulatory dysfunctional uterine bleeding and users of intrauterine contraceptive devices; (ii) breastfeeding post-partum women in whom there are long periods of amenorrhoea, particularly in the early months post-partum; and (iii) normal cycling women. It was found that the total activity of lysosomal enzymes, particularly acid phosphatase and N-acetyl-beta-D-glucosaminidase, was markedly elevated (P < 0.001) in IUCD-exposed endometrium, and endometrium from women with dysfunctional uterine bleeding when compared with endometrium from women with a history of entirely normal menstrual periods or that in post-partum breastfeeding women. The activity of alpha-L-fucosidase was moderately elevated in IUCD users (P < 0.05) and ovulatory dysfunctional uterine bleeding (P < 0.05), whereas alphaD-mannosidase activity was elevated in ovulatory dysfunctional uterine bleeding (P < 0.05), but decreased in IUCD users (P < 0.01). No significant differences were observed in the lysosomal enzyme activities of breastfeeding post-partum women and normal cycling women. These results show that total endometrial tissue activity of four lysosomal enzymes was substantially increased throughout the cycle in most circumstances in women with two different causes for increased menstrual bleeding. This suggests a contributory role to the increased bleeding.