Mode of insecticidal action studied with labelled systems. Phosphorylated compounds in the muscle of the adult housefly, Musca domestica, L

Abstract

The adult housefly was fed carrier-free P32O4. The radioisotope was incorporated into the acid-soluble phosphorylated compounds of thoracic tissue. These compounds were extracted and separated on paper chromatograms and assayed by an automatic radiometric scanning technique. The major fractions separated are tentatively indentified as adenosine triphosphate (ATP), adenosine diphosphate (ADP), muscle adenylic acid (AMP), glucose 6-phosphate, arginine phosphoric acid, phosphoglycerate and free orthophosphate. Evidence was obtained that all the P atoms of the ATP and ADP fractions were equally labelled. The histological distr. of the p32 was studied by an autoradiographic technique. A relatively high concentration of P32 in the gut of the thorax was found but appeared to be of the same chemical composition as that of the muscle. The effects of motor activity and cyclopropane anaesthesia upon the distribution of labelled intermediates appeared consistent with current views in muscle biochemistry. The phosphorylated compounds of resting housefly and mammalian muscle were compared. Relatively low phosphagen and high phosphoglycerate levels in the insect were noted.