Dopamine depresses the immune ability and increases susceptibility to Lactococcus garvieae in the freshwater giant prawn, Macrobrachium rosenbergii.
The total haemocyte count (THC), phenoloxidase activity, respiratory burst (release of superoxide anion), superoxide dismutase activity, and phagocytic activity and clearance efficiency to the pathogen Lactococcus garvieae were measured when freshwater giant prawns Macrobrachium rosenbergii (16.2 +/- 2.1 g) were individually injected with saline, or dopamine at 0.5, 5.0, or 50.0 pmol prawn(-1). The results show that a transient period of immunosuppression occurred between 2 and 8 h after injection of dopamine for all immune parameters except circulating haemocytes and all immune parameters returned to control values within 8-16 h after receiving dopamine. Injection of dopamine also significantly increased the mortality of M. rosenbergii challenged with the pathogen L. garvieae. These results suggest that stress-inducing dopamine suppresses the immune system, which in turn promotes the susceptibility to L. garvieae in M. rosenbergii.
Li
Jian-Tong
JT
Department of Aquaculture, National Pingtung University of Science and Technology, Taiwan.
Lee
Pai-Po
PP
Chen
Ou-Chuan
OC
Cheng
Winton
W
Kuo
Ching-Ming
CM
D000818:Animals; D000917:Antibody Formation / Q000187:drug effects*; D001772:Blood Cell Count; D004298:Dopamine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005618:Fresh Water; D007111:Immunity, Cellular / Q000187:drug effects*; D017045:Lactococcus; D014442:Monophenol Monooxygenase / Q000378:metabolism; D033541:Palaemonidae / Q000276:immunology* / Q000382:microbiology*; D010587:Phagocytosis / Q000187:drug effects; D016897:Respiratory Burst / Q000187:drug effects; D013482:Superoxide Dismutase / Q000378:metabolism; D013997:Time Factors
D014442:Monophenol Monooxygenase; D013482:Superoxide Dismutase; D004298:Dopamine