Effect of a Trehalase Inhibitor, Validoxylamine A, on Three Species of Flies

Abstract

Effects of a trehalase inhibitor, validoxylamine A (VAA), on the activity and haemolymph components were studied in three species of flies, Musca domestica, Boettcherisca peregrina and Calliphora nigribarbis. Haemolymph components were analyzed by NMR spectrometry. Overall activity of the housefly was suppressed by VAA injection (2.5 μg/fly) and 30% of them died in 2 days. The activity of the fleshfly also decreased but without death (2μg/fly). VAA injection (5 μg/fly) acted, however, stimulatively rather than suppressively on the blowfly flight. Trehalose concentration in the haemolymph rose by VAA injection in a day to 2.6, 3.3 and 3.7 times in M. domestica, B. peregrina and C. nigribarbis, respectively. The trehalose accumulation seemed to be caused by inhibition of trehalose metabolism and by active synthesis of the trehalose from glucose by inhibition of trehalose metabolism and by active synthesis of the trehalose from glucose which was not affected by VAA injection. The result that inhibition of trehalose metabolism did not evoke the reduction of the flight activity in the blowfly, suggests the use of alternative energy source in its body.