HYPERGLYCEMIA OR HYPERTREHALOSAEMIA - THE EFFECT OF INSECT NEUROPEPTIDES ON HEMOLYMPH SUGARS

Haemolymph of various insect species (four cockroaches, one tenebrionid beetle and one stick insect) was purified by isocratic high performance liquid chromatography on an amino-phase support. The purified sugars were detected and quantified using a refractive index monitor. Injection of 10 pmol of the respective native synthetic neuropeptide caused an increase in the trehalose concentration in all species, but no significant changes in the glucose level. In stick insects, the hypertrehalosaemic effect could be detected only in ligated animals, the haemolymph of non-ligated insects showing no change in any sugar component after neuropeptide injection.