硫化物胁迫对日本沼虾呼吸代谢和能量代谢酶的影响

Effects of sulphide on the enzyme of respiratory metabolism and energy metabolism of Macrobrachium nipponense

研究了硫化物暴露后日本沼虾细胞色素氧化酶(CCO)、琥珀酸脱氢酶(SDH)、延胡索酸还原酶(FRD)和乳酸脱氢酶(LDH)4种呼吸代谢酶及能量代谢酶—精氨酸激酶(AK)活性的变化规律。将日本沼虾暴露于0.6mg·L-1、2mg·L-1的2个硫化物质量浓度组和不含硫化物的对照组水体中,暴露后0、2、12、24、48h和解除暴露后48h取肝胰腺和肌肉组织进行酶活性分析。结果显示:肝胰腺和肌肉组织SDH和CCO活性随硫化物质量浓度升高或暴露时间延长而显著降低(P<0.05)。FRD、LDH和AK活性随硫化物质量浓度升高或暴露时间延长而显著升高(P<0.05)。解除硫化物暴露后48h,各质量浓度组酶活性与对照组无显著差异。上述酶活性还存在组织差异,肝胰腺呼吸代谢酶活性高于肌肉中相应酶活性,而AK活性与此相反。结果表明,硫化物胁迫导致日本沼虾有氧呼吸代谢减弱,无氧呼吸代谢增强,并动用其能量贮存物质磷酸精氨酸,产生更多ATP以适应外界不良环境。

In this paper, series of Macrobrachiurn nipponense enzyme activity changing after exposing to different concentrations of sulphide were investigated. The investigated enzymes included respiratory metabolic enzymes_cytochrome c oxidase （CCO）, succcinate dehydrogenase （SDH）, fumarate reductase （FRD）, lactate dehydrogenase （LDH）; energy metabolic enzymes_arginine kinase （AK）. The sulphide concentrations were set at 0.6 and 2 mg-L^-1 and the control with no sulphide. Hepatopancreas and muscle tissues were sampled at 0, 2, 12, 24 and 48 h. Enzyme activities were tested after 48 h of sulphide exposure removal. The results indicated that with the duration of sulphide exposure and the increase of concentration, CCO and SDH activities were significantly decreased （with P 〈 0.05）, meanwhile FRD, LDH and AK activities were significantly increased （with P 〈 0.05）. After 48 h of sulphide exposure removal, enzyme activities of respiratory metabolic enzymes and AK returned to normal level and there was no significant difference between the experimental groups and the control group. The enzymes showed tissue dependent. Respiratory metabolic enzymes in hepatopancreas showed higher enzyme activities than that of musle＇s while AK activities of hepatopancreas were lower than that of muscle＇s. It suggested after exposing to sulphide that aerobic metabolism decreased and anaerobic metabolism increased. Arginine phosphate was consumed and transferred its high-energy phosphate bond to ATP as a response to sulphide environment.