Cyclic AMP in developing muscle of the rhesus monkey: effect of prostaglandin E.

Cyclic AMP levels, measured by a competitive protein-binding assay and by a prelabeling technique with adenine-14 C, were determined on fetal, infant, and adult heart, diaphragm, and skeletal muscle of the rhesus monkey (Macaca mulatta); the effect of PGE on cyclic AMP accumulation was also studied. The levels of cyclic AMP were higher in the 3 types of muscle from 150-day fetuses (91% of term) than in adult muscles and even higher at 78-100 days fetal age, and histological evidence indicated that by 65 days gestation, the majority of the rhesus skeletal muscle cells are in the myotube stage. These data agree with the observation in cell cultures that a decrease in cyclic AMP is correlated with fusion of myoblasts to form myotubes. PGE (2.8 MUM) stimulated cyclic AMP accumulation in all the fetal series, even in the earliest series (47% of term), as well as in all the adult series.