鱼类低温适应机制的研究——(Ⅰ)驯化温度对草鱼和鲮鱼几种同工酶活性及酶谱的影响

STUDY ON THE MECHANISM OF LOW TEMPERATURE ADAPTATION IN FISH I. EFFECTS OF ACCLIMATION TEMPERATURE ON ISOZYME ACTIVITIES AND ISOZYME PATTERNS IN TISSUES OF GRASS CARP AND MUD CARP

采用分光光度法测呈了25℃和10℃驯养的草鱼、鲮鱼、二代混精鲮鱼及对照组混精鲮鱼的肌肉和肝脏组织中乳酸脱氨酶(LDH)、6-磷酸葡糖脱氨酶(G6PDH)和异柠檬酸脱氢酶(IDH)活性的变化;采用电泳法对LDH、酯酶(EST)和超氧化物歧化酶(SOD)的同工酶酶谱进行了比较研究。实验结果表明,草鱼肝脏组织在低温下发生了代谢途径的转换和重组,而鲮鱼的肌肉组织和肝脏组织都只采取了增加酶浓度的方式。鲮鱼代谢转换机制的不完善,可能是鲮鱼不耐低温的重要原因之一。三组鲮鱼肝脏组织的酯酶(EST)同工酶谱在不同适应温度下的变化表明,鲮鱼肝脏组织的酯代谢在低温下发生了变化。最后,作者对混精授精法提高鲮鱼耐寒能力的作用进行了评价。

Spectrophotometric techniques were used to monitor the changes of isozyme activities in liver and muscle tissues ol the grass carp,mud carp,second successive generation mud carp derived from eggs fertilized with mixed-milt,and linebred progeny of mud carp originally derived from eggs fertilized with mixed -milt as control after thermal acclimation. The results showed that some metabolic reorganizations occurred in the liver tissue of the grass carp during cold acclimation ,and that increasing enzyme concentration was the major or only response in the tissues of the mud carp. The authors consider that the mechanism of metabolic reorganizations is not perfect in the tissues of mud carps,which is the major reason why they can not tolerate temperature lower than 6 - 7℃. The changes in the isozyme patterns of esterase (EST)in liver tissue of the three tested mud carp sets indicated that some changes must have occurred in the lipid metabolism of their liver tissues during thermal acclimation. The effect of the Mixed - milt Fertilization Method on improving the capacity for low temperature tolerance in mud carp was discussed at the end of the paper.