The metabolism of glycerol in the locust Schistocerca gregaria during flight

The concentration of glycerol in locust haemolymph increases 10-fold during 1 hr flight but decreases rapidly when flight ceases. ¹⁴C]Glycerol is rapidly metabolized by locusts in vivo. Trehalose and diacyl glycerol are the main products to appear in the haemolymph but the proportion of diacyl glycerol is increased in flown insects or when adipokinetic hormone is injected. Trehalose and diacyl glycerol are also the main products formed when isolated fat body is incubated with ¹⁴C]glycerol. Adipokinetic hormone increases the proportion of diacyl glycerol formed.It is proposed that during flight glycerol is produced by hydrolysis of diacyl glycerol in the flight muscles. It is then transported to fat body for esterification with fatty acid produced during conversion of triacyl glycerol stores to diacyl glycerol.