Glycogen metabolism in vesicles of hydatidiform mole in vitro.

Glycogen content, glycogen synthetase, and glycogen phosphorylase were studied in placental tissue of normal pregnancy and in vesicles of hydatidiform mole. The glycogen content of placental tissue of normal pregnancy decreased significantly with increased gestational age: 6 to 10 weeks, 716.6 +/- 55.7 mg/100 gm wet weight (mean +/- standard error of the mean); 15 to 20 weeks, 216.1 +/- 11.2 mg/100 gm; and 37 to 41 weeks, 176.1 +/- 18.1 mg/100 gm. The decrease in placental glycogen content was accompanied by a corresponding decrease in the placental glycogen synthetase enzyme levels, whereas no remarkable change was found in the glycogen phosphorylase enzyme levels. The glycogen content of hydatidiform mole tissue from 10 patients (13 to 20 weeks of gestation) was 507.0 +/- 58.0 mg/100 gm and was significantly (P less than 0.005) higher than that of normal placental tissue with a corresponding period of gestation. A possible cause of this phenomenon may be the marked decrease in the glycogen phosphorylase enzyme level in hydatidiform mole tissue, which was about one-third that of the normal placental tissue.