PHYSIOLOGICAL CHANGES IN SIGANUS CANALICULATUS AFTER SHALLOW WATER STRESS AND THE ANTI-STRESS EFFECTS OF TAURINE

In this study several physiological indicators to stress of rabbitfish were investigated after the subject were shortly (4min) exposed to the shallow water stress. The recovery process were studied at 20, 40, 60, 80min post stress. In addition, the anti-stress effects of taurine were evaluated. The results showed that the serum adrenaline level was significantly increased from (2.000.22) ng/mL to (15.121.04) ng/mL after the exposure to stress (P0.05), and then gradually returned back to basal levels. No significant changes were observed in serum cortisol and cholesterol concentrations (P0.05). The serum glucose level reached the maximum level (7.100.38) mmol/L at 20min post the stress, which was 3.5 times higher than the basal level (P0.05). The expression of HSP70 mRNA in brain reached the maximum level at 60min post the stress, which was 11.54 times higher than the basal level (P0.05). Besides, the incubation with 20 ppm taurine significantly reduced the serum adrenaline, glucose and brain HSP70 mRNA levels after stress (P0.05). These results suggested that sympathetico-chromaffin system might be, if not all, at least one of the apparatus that account for rabbitfishs response to the acute stress. During this process adrenaline is released to elevate the blood glucose level which results in the boost in the energy. The increase in brain HSP70 expression also enhances the protective effect of organism. Noticeably taurine has the anti-stress effects in rabbitfish to certain extent.