PFOS对中华倒刺鲃幼鱼爆发游泳及运动后代谢恢复的影响

EFFECTS OF PFOS ON BURST SWIMMING PERFORMANCE AND METABOLIC RECOVERY IN JUVENILE SPINIBARBUS SINENSIS

为探究水体全氟辛烷磺酸(PFOS)污染对鱼类爆发游泳及其代谢恢复能力的影响,将中华倒刺鲃幼鱼(Spinibarbus sinensis)暴露在不同浓度(0、0.32、0.8、2和5 mg/L)PFOS后,测定PFOS暴露对其静止代谢率(RMR)、爆发游泳速度(Uburst)以及运动力竭后代谢恢复特征的影响。结果发现,暴露浓度对实验鱼的Uburst和相对爆发游泳速度(rUburst)均影响显著(P<0.05),5 mg/L PFOS暴露导致Uburst和rUburst分别下降了17.4%和10.8%,PFOS对rUburst的影响表现出"非单调剂量效应";暴露浓度对实验鱼的RMR影响显著(P<0.05),5 mg/LPFOS暴露导致RMR显著升高,但PFOS对运动后代谢峰值(MMR)、代谢率增量(MS)、代谢变化倍率(F-MS)、力竭运动后过量氧耗(EPOC)无显著影响(P>0.05)。研究结果提示:PFOS污染改变实验鱼能量代谢水平的下限,而对其代谢水平的上限无明显的限制性作用;PFOS污染将可能对鱼类捕食——逃避捕食者、穿越激流寻找适宜生境等生存关联的生命活动起到负面影响,但对无氧代谢关联的代谢恢复能力无显著的生态毒理效应。

To assess the effects of PFOS pollution on burst swimming performance and metabolic recovery of fish,juvenile Spinibarbus sinensis were exposed to different PFOS concentrations(0,0.32,0.8,2 and 5 mg/L)for 28d.There after,the burst swimming speed(Uburst),relative Uburst(rUburst),resting metabolic rate(RMR)and metabolic recovery after exhaustive swimming of the fish were measured.The results showed that PFOS had a profound effect on the Uburst and rUburst of fish(P<0.05).The Uburst and rUburst were reduced by 17.4%and 10.8%,respectively,upon exposure to 5 mg/L PFOS.A possible non-monotonic dose response was found in rUburst to PFOS.Moreover,PFOS significantly increased RMR(P<0.05),but did not have a marked effect on maximum metabolic rate(MMR),metabolic scope(MS),factorial metabolic scope(F-MS)and excess post-exercise oxygen consumption(EPOC)(P>0.05).The results indicated that PFOS had more dramatical effect on RMR than MMR of the experimental fish.Presumably,PFOS negatively impact survival-related activities such as capturing prey,avoiding predators,hunting for suitable habitats without significant ecotoxicological effects on metabolic recovery associated with anaerobic metabolism.