Modulation by biogenic amines for the hemocyte count and prophenoloxidase exocytosis via receptors in Litopenaeus vannamei

Abstract

Hemocyte counts and phenoloxidase (PO) activity were examined after hemolymph being incubated in dopamine (DA), noradrenaline (NE) and serotonin (5-HT). Results showed that all the three biogenic amines (BAs) had a significant impact on total hemocyte count (THC), differential hemocyte count (DHC), and intracelluar and extracelluar phenoloxidase (PO) activity. Among these Bas, DA had the strongest effect on the above parameters, whereas 5-HT had the least effect. Preincubation with D1 receptor antagonist SCH23390, D2 receptor antagonist Sulpiride and 1:1 admixture of the two could significantly inhibit the effect of DA on these parameters. SCH23390 showed a stronger inhibitory effect than Sulpiride, and the admixture exhibited the strongest effect. These results suggested that the change of hemocyte count and activation of prophenoloxidase (proPO) system in Litopenaeusvannamei hemocyte can be regulated by BAs, and DA modulates the two parameters via its receptors.

Neuroendocrine‐immune regulation mechanism in crustaceans: A review

“…It has been reported that BA plays a vital role in crustacean immune defence by regulating the total haemocyte count and the activity of prophenoloxidase (proPO) system in L. vannamei. 99 Besides, only one small molecule transmitter aminobutyric acid (GABA) was formally detected in the pericardial organ of crustacean (Cancer borealis and Cancer productus) via immunoreactivity. 98,100 In addition, it has been shown that gas transmitter (nitric oxide) was produced in the SG of Procambarus clarkia (P. clarkia).…”