Thorndyke, MichaelKristineberg Marine Research Station, Fiskebäckskil, Sweden
Author
Holmgren, SusanneDepartment of Zoophysiology, Göteborg University
Author
Abstract
The role of nitric oxide ( NO) in the control of bioluminescence ( light production) in the crustacean Meganyctiphanes norvegica ( krill) was investigated using pharmacological and immunohistochemical methods. All nitrergic drugs tested failed to induce bioluminescence per se but modulated light production stimulated by 5-hydroxytryptamine (5-HT). NO donors [ sodium nitroprusside ( SNP) and S-nitroso-N-acetylpenicillamine ( SNAP)] injected in live specimens significantly reduced light production stimulated by 5-HT, whereas inhibition of the enzyme NO synthase ( NOS) with L-NAME (N-G-nitro-L-arginine methyl ester) resulted in an enhancement of the 5-HT response. The effects of NO do not seem to be mediated via production of cGMP as injections of a cGMP analogue (8-Bromoguanosine 3',5'-cyclic monophosphate) gave inconclusive effects on the 5-HT-stimulated light response. Inhibition of cGMP production with ODQ (1H-[1,2,4] oxadiazolo[4,3-a] quinoxalin-1-one) did not affect the light response. Moreover, a few individuals showed a considerably higher response to 5-HT in April and June compared with specimens collected in the autumn and winter. Furthermore, both NOS-like and 5-HT-like materials were detected by immunohistochemistry inside the light organs. NOS-like immunoreactivity was primarily observed in structures associated with vessels inside the light organs, whereas 5-HT-like material was abundant in nerve fibres throughout the whole light organ. The results suggest that NO has a modulatory role at several levels in the control of light production in M. norvegica and that NO and 5-HT interact in this regulation.
Kronstrom, J., Dupont, S., Mallefet, J., Thorndyke, M., & Holmgren, S. (2007). Serotonin and nitric oxide interaction in the control of bioluminescence in northern krill, Meganyctiphanes norvegica (M. Sars). The Journal of Experimental Biology, 219(18), 3179-3187. https://doi.org/10.1242/jeb.002394 (Original work published 2007)