Stimulatory effects of bioamines norepinephrine and dopamine on locomotion of Pyrrhocoris apterus (L.): is the adipokinetic hormone involved?
In the present paper we studied the effects of five biogenic amines - norepinephrine, dopamine, octopamine, serotonin and histamine - on the locomotory activity and mobilization of lipids in the adult females of the firebug, Pyrrhocoris apterus (L.). We tested the hypothesis (1) whether the stimulation of walking activity in the bugs injected with the bioamines is associated also with their hyperlipaemic effects, like in the case of adipokinetic hormones (AKHs), and (2) whether these effects are direct or mediated through a release of the AKHs into the hemolymph. The results demonstrated that all five tested biogenic amines mobilized the fat body lipids, but only norepinephrine and dopamine were capable to enhance the walking activity simultaneously with an elevation of the lipid level in the hemolymph. Those two amines had no effect on the level of AKHs in CNS, but modulated the AKHs level in hemolymph: norepinephrine increased it, while dopamine decreased it. The results indicate an apparent feedback between AKH characteristics and dopamine and norepinephrine actions occurring in this insect species. While the stimulatory effects of norepinephrine on lipid mobilization and walking activity could involve the release of bug's own AKHs, dopamine probably employs an independent stimulatory pathway.
Socha
Radomír
R
Institute of Entomology, Biology Centre ASCR, Branisovská 31, Ceské Budejovice, Czech Republic.
Kodrík
Dalibor
D
Zemek
Rostislav
R
D000818:Animals; D004298:Dopamine / Q000494:pharmacology* / Q000502:physiology; D005216:Fat Body / Q000378:metabolism; D005260:Female; D006458:Hemolymph / Q000378:metabolism; D020062:Heteroptera / Q000187:drug effects / Q000502:physiology*; D006632:Histamine / Q000494:pharmacology / Q000502:physiology; D007301:Insect Hormones / Q000502:physiology*; D050356:Lipid Metabolism; D008124:Locomotion / Q000187:drug effects / Q000502:physiology*; D009638:Norepinephrine / Q000494:pharmacology* / Q000502:physiology; D009655:Octopamine / Q000494:pharmacology / Q000502:physiology; D009842:Oligopeptides / Q000502:physiology*; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives*; D012701:Serotonin / Q000494:pharmacology / Q000502:physiology
D007301:Insect Hormones; D009842:Oligopeptides; C044833:adipokinetic hormone; D009655:Octopamine; D012701:Serotonin; D006632:Histamine; D011761:Pyrrolidonecarboxylic Acid; D004298:Dopamine; D009638:Norepinephrine