In vitro effects of noradrenaline on Sydney rock oyster (Saccostrea glomerata) hemocytes.
Our prior work has shown that the catecholamine hormone, noradrenaline, mediates environmental stress responses in Sydney rock oysters, resulting in impaired immunological function. In the current study, we tested the cellular basis of this stress response. Hemocytes were exposed to noradrenaline in vitro before cell morphology and viability were analyzed. Noradrenaline was shown to induce apoptotic markers, including the loss of mitochondrial membrane potential, DNA fragmentation and plasma membrane blebbing. F-actin appeared to play an important role in the changes observed in hemocytes, being concentrated mostly in the plasma membrane blebs of noradrenaline-treated hemocytes. This may explain why hemocyte adhesion and pseudopodia formation were inhibited by noradrenaline. Cellular dysfunction induced by norarenaline mainly affected the hyalinocyte sub-population of hemocytes, whilst the other major cell type, granulocytes, remained unaffected. Given that hyalinocytes are important immunological effectors, the results of this study help to explain why immunosuppression accompanies noradrenaline-mediated stress responses in oysters.
Aladaileh
Saleem
S
Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia.
Mohammad
Mohammad G
MG
Ferrari
Belinda
B
Nair
Sham V
SV
Raftos
David A
DA
D000199:Actins / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D017756:Aquaculture; D002448:Cell Adhesion / Q000187:drug effects; D006434:Hemocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology* / Q000378:metabolism; D007108:Immune Tolerance / Q000187:drug effects; D066298:In Vitro Techniques; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D009638:Norepinephrine / Q000494:pharmacology*; D010125:Ostreidae / Q000166:cytology / Q000187:drug effects* / Q000276:immunology* / Q000378:metabolism; D013312:Stress, Physiological
D000199:Actins; D009638:Norepinephrine