高盐胁迫对黄边糙鸟蛤(Trachycardium flavum)呼吸排泄和免疫酶活性的影响

为了探讨急性高盐胁迫对黄边糙鸟蛤(Trachycardium flavum)生理代谢和免疫酶活性的影响,分析了盐度自31骤升至37后2、12、24、48和72 h黄边糙乌蛤耗氧率、排氨率和不同组织Na+/K+-ATP酶、超氧化物歧化酶(SOD)、酸性磷酸酶(ACP)和碱性磷酸酶(ALP)的活性.结果显示,处理后2h耗氧率先降低,然后逐渐升高,在24和72 h显著高于对照组(P＜0.05);排氨率在2h极显著降低(P＜0.01),且在各时间点均低于对照组.外套膜、肝胰腺中Na+/K+-ATP酶活力在12 h显著降低(P＜0.05),肌肉和鳃中活力与对照组无显著差异.外套膜、肝胰腺和鳃中SOD活力在24 h达到最高值,显著高于对照组(P＜0.05),其后逐渐降低;肌肉中SOD活力在48 h达到最高值后降低.外套膜和鳃中ACP活力先升高后降低,肝胰腺中ACP活力显著降低(P＜0.05)后逐渐升高,肌肉中ACP活力与对照组无显著差异.肝胰腺和鳃中ALP活力先降低后显著升高(P＜0.05),与对照组相比,外套膜和肌肉中ALP活力无显著差异.结果表明,急性高盐胁迫对黄边糙鸟蛤的代谢水平和免疫酶活性均有显著影响且表现出时间效应性,高盐胁迫对免疫酶活性的影响具有组织特异性.

Effects of Acute Hyperosmotic Stress on Metabolic Rates and Immune-Related Enzymatic Activities in Clam (Trachycardium flavum)

To investigate the effects of acute hypersaline stress on the physiological metabolism and immunity of clam Trachycardium flavum. The oxygen consumption rate, ammonia excretion rate and activities of Na+/K+-ATPase, superoxide dismutase (SOD), acid phosphatase (ACP) and alkaline phosphatase (ALP) in different tissues were measured at 2, 12, 24, 48 and 72 h as water salinity increased from 31 to 37. Results showed that the oxygen consumption rate of clams in treatment group decreased at 2 h and then gradually increased, and was significantly higher than the control group at 24 and 72 h (P<0.05). The ammonia excretion rate significantly decreased (P<0.01) at 2 h and was lower than the control group at all time points. At 12 h, the clams showed significant lower Na+/K+-ATPase activity (P<0.05), but no significant difference of Na+/K+-ATPase activity in muscle was found between the control and treatment groups. SOD activities in mantle, hepatopancreas and gill reached maximum values at 24 h, which was significantly higher than the control group(P<0.05), and then decreased; SOD activity in muscle reached a peak at 48 h and then declined. ACP activity in mantle and gill showed similar variation as SOD. ACP activity was significantly reduced (P<0.05) and then gradually rose. No significant difference of enzymatic activity in muscle was found between the control and treatment groups. ALP activity in hepatopancreas and gill decreased followed by significant increase (P<0.05). Compared with the control group, no significant difference of enzymatic activity in mantle and muscle was found. The results suggested that acute hypersalinet stress significantly affected the metabolism and immunity of T. flavum, and such effects varied with time. The impact of hypersaline on the immune enzymatic activities is tissue-specific.