THE ROLE OF BIOGENIC-AMINES IN THE CONTROL OF BLOOD-GLUCOSE LEVEL IN THE DECAPOD CRUSTACEAN, CARCINUS-MAENAS L

1. Administration of biogenic amines into intact Carcinus maenas induces dose- and time-dependent elevation of hemolymph glucose level. 2. Removal of the neurosecretory centre containing the crustacean hyperglycemic hormone (CHH) by ablation of the eyestalks did not induce hypoglycemia. 3. Injection of dopamine (DA) into eyestalkless crabs showed no hyperglycemic effect, while serotonin (5-HT), epinephrine (E), norepinephrine (NE), and octopamine (OA) elevated glucose levels. 4. The dopaminergic effect was significantly reduced by administration of trifluoperazine (TFP). 5. 5-HT and OA were found to be strong elevators of glucose levels, while the other biogenic amines had moderate effects only. 6. The results indicate, that DA exerts its hyperglycemic effect by stimulating the release of CHH from the eyestalk neurosecretory centre. Elevation of hemolymph glucose level by 5-HT, OA, E, and NE, occurs independently of CHH.