家蚕氟中毒对雌雄个体Na^+-K^+-ATPase活性的影响

Effects of Fluoride on Na^+-K^+-ATPase Activity in Bombyx mori of Different Sexes

为探明家蚕的耐氟性机制以及耐氟性在不同性别蚕体间的差异,以家蚕耐氟品种T6和氟化物敏感品种734为材料,从5龄起蚕开始分雌、雄喂食清水和经200mg/kg NaF浸泡的新鲜桑叶,检测家蚕头部酶液中Na+-K+-ATPase的活性变化,研究发现:敏感品系734各组酶活随处理天数的不同而不同,对照组在第3天酶活达到最低,而添氟组酶活则在第2天出现最低值,从第3天开始添氟组酶活均高于对照组;雌、雄间酶活亦有差异,734雌蚕对照组各天的酶活均高于雄蚕对照组,平均活力为雄蚕的1.6倍,而添氟组雄蚕的Na+-K+-ATPase平均酶活为雌蚕的1.11倍.耐氟品种T6各组酶活及其随处理天数的变化趋势均与对照组较为一致;雌、雄间酶活都有差异,雌蚕对照组Na+-K+-ATPase平均酶活是雄蚕对照组的1.11倍,雌蚕添氟组Na+-K+-ATPase平均酶活是雄蚕添氟组的1.10倍.推测氟化物处理后耐氟家蚕品种仍然能够保持Na+-K+-ATPase活力水平,从而表现对氟化物的耐受性;添氟前后雌雄间的Na+-K+-ATPase活性差异在2个蚕品种间有所不同,可能暗示T6耐氟性的产生与雌蚕的解毒能力增强有关.

To explore the mechanism（s） of fluoride resistance in Bombyx mori and the difference in resistance between male and female B.mori larvae,the fluoride-resistant silkworm variety T6 and the fluoride-sensitive variety 734 were used as experimental materials.The 5th instar newly exuviated larvae of both sexes were fed with mulberry leaves which had been soaked in clean water or in 200 mg/kg NaF solution and the variation in Na＋-K＋-ATPase activity in their head was examined.Na＋-K＋-ATPase activity in the head of the 5th instar larvae of 734 reached the lowest values at day 3 in the control group and at day 2 in the fluoride-treated group,and it was higher in the fluoride-treated group than in the control group from day 3.The activity of Na＋-K＋-ATPase in head of the 5th instar female larvae of 734 in the control group was higher,1.6 times in average,than that of the male larvae throughout the experimental period,but the average activity of Na＋-K＋-ATPase in male larvae of 734 in the fluoride-treated group was 1.11 times as high as that of the female larvae.The Na＋-K＋-ATPase activity and activity variation trend of the 5th instar larvae of T6 in the fluoride-treated group were similar to those of the control group;the average activity of Na＋-K＋-ATPase in female larvae of T6 in the control group was 1.11 times as high as that in male larvae,and the average activity of Na＋-K＋-ATPase in female larvae of T6 in fluoride-treated group was 1.10 times as high as that of the male larvae.It was assumed that Na＋-K＋-ATPase activity could be maintained in the fluoride-resistant silkworm variety T6 after fluoride treatment,thus conferring this variety with fluoride tolerance.The difference in Na＋-K＋-ATPase activity of different sexes between the control group and the fluoride-treatment group was inconsistent between the two silkworm varieties,which suggested that the resistance to fluoride of T6 may be associated with the enhanced detoxication ability of the female silkworm.