Abstract
Investigations were made on the P32 incorporation into the phospholipid fractions in thoracic muscle of dragon fly comparing with heart and femoral muscles of rat. The results obtained by the paperchromatographic method of Dawson were as follows :
1) The total phosphatidylserine, phosphatidylethanolamine and phosphatidylcholine content was more than 70% of the total phospholipids in thoracic muscle of dragon fly, but the diphospho-in ositide content was low.
2) The incoporation of P32 into phosphatidylserine reached its maximum three hours after the ingestion of P32, but those into phosphatidylcholine and two unidentified substances (Rf value of them was about 0.25 in paperchromatography by phenol-NH3) were gradually increased ouere period of 20 hours. After 20 hours of P32 ingestion, more than 80% of P32 incorporated into total phospholipids were in the fractions of phosphatidylcholine and two unidentified substances referred to above.
3) The composition of phospholipids of heart and femoral muscles of rat after intraperitoneal injection of P32 were almost the same as that of dragon fly. The P32 incorporation into diphospho-inositide and two unidentified substances of heart muscle of rat were greater than that of femoral muscle after 12 hours, while that of phosphatidylserine was the reverse.
The results were discussed as to the significance of phospholipids as an important endogenous substrate of muscles, especially of insect flight muscle.
