Endometriosis impairs glycogen synthesis in human endometrium

Glycogen content in endometrium with endometriosis was about half of that without endometriosis at the secretory phase, whereas no difference was found in the proliferative phase. The activity of glycogen synthetase in endometrium with endometriosis was reduced to 25% and 23% of that without endometriosis in the late proliferative and midsecretory phase, respectively. The activity of glycogen phosphorylase was also significantly lower in endometrium with endometriosis in the late proliferative phase. However, the activity increased conspicuously in the midsecretory phase, and thus there was no difference in activity in endometrium with or without endometriosis. The observed lowered capacity of glycogen synthesis may lead to understanding the mechanism of infertility associated with endometriosis.