Diacylglycerol-transporting lipoproteins and flight in Locusta

• Published in: Journal of insect physiology Vol. 27; no. 1; pp. 47 - 50
• Main Authors: Mwangi, R.W., Goldsworthy, G.J.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 1981
• Subjects: animal physiology; arthropods; entomology
• ISSN: 0022-1910; 1879-1611
• DOI: 10.1016/0022-1910(81)90031-7

Evidence from chromatographic and heparin precipitation studies shows that the ‘heparin-soluble’ lipoprotein, A +, forms in the haemolymph during flight. In locusts flown continuously for 60 min, lipoprotein A + occurs in the haemolymph at low concentrations but accumulates during a short rest period following flight. After injections of tissue extracts containing adipokinetic hormone (AKH), A + accumulates in the haemolymph but disappears more rapidly in flying locusts than in resting locusts. This difference in the rate of disappearance of diacylglycerol from the lipoprotein A + can be used to estimate its rate of utilization during sustained flight (approx. 100μg. min −1 from 45–90 min of flight). It is suggested that lipoprotein A + is the major carrier of diacylglycerol from the fat body to the flight muscles during prolonged flight. The steady state concentrations of total diacylglycerol and ‘heparin-soluble’ diacylglycerol during continuous flight are unaffected when tissue extracts containing AKH are injected before flight. This suggests that there is a close homeostatic control over the steady state concentration of haemolymph lipid during flight.