Systemic Physiological and Ecotoxicological Research (SPHERE), Department of Biology, University of Antwerp, Antwerp 2020, Belgium
Systemic Physiological and Ecotoxicological Research (SPHERE), Department of Biology, University of Antwerp, Antwerp 2020, Belgium.
J Exp Biol. 2019 Dec 10;222(Pt 23):jeb212035. doi: 10.1242/jeb.212035.
Nitrite is a widespread form of pollution that directly lowers the blood oxygen carrying capacity of aquatically respiring species. It is unknown if this impairment of oxygen transport translates into an increased susceptibility to elevated temperatures. We hypothesised that nitrite exposure would lower blood oxygen carrying capacity and decrease both aerobic scope (maximum-standard metabolic rate) and heat tolerance. To test these hypotheses, juvenile European carp () were exposed to two levels of nitrite (0 mmol l or 1 mmol l) for 7 days and haematological parameters, critical thermal maxima (CT) and aerobic scope were assessed. Nitrite exposure reduced total haemoglobin by 32.9%. Aerobic scope remained unchanged in fish exposed to nitrite; however, marked declines in CT (1.2°C reduction) were observed in nitrite-exposed fish. These findings demonstrate that nitrite exposure can significantly impair heat tolerance, even when aerobic capacity is maintained.
亚硝酸盐是一种广泛存在的污染形式，它会直接降低水生呼吸物种的血液携氧能力。目前尚不清楚这种氧气运输的损害是否会导致对高温的敏感性增加。我们假设亚硝酸盐暴露会降低血液的携氧能力，并降低有氧范围（最大标准代谢率）和耐热性。为了验证这些假设，我们将幼年欧洲鲤鱼暴露于两种亚硝酸盐水平（0mmol/L 或 1mmol/L）下 7 天，并评估血液学参数、临界热极值（CT）和有氧范围。亚硝酸盐暴露使总血红蛋白减少了 32.9%。暴露于亚硝酸盐的鱼类的有氧范围保持不变；然而，在亚硝酸盐暴露的鱼类中观察到 CT（降低 1.2°C）明显下降。这些发现表明，即使有氧能力得到维持，亚硝酸盐暴露也会显著降低鱼类的耐热性。
