Postgraduate Program in Pharmaceutical Sciences, Department of Pharmaceutical Sciences, Federal University of Espírito Santo, Vitória, ES, Brazil.
Department of Physiology, Faculty of Health & Medical Sciences, University of Auckland, Grafton, Auckland, 1142, New Zealand.
Cardiovasc Toxicol. 2019 Dec;19(6):548-564. doi: 10.1007/s12012-019-09528-7.
Previous studies showed that chlorpyrifos (CPF) acute exposure impaired cardiorespiratory reflexes. Evidence also indicates that continuous exposure to organophosphorus compounds impairs cardiovascular function. However, the effect of intermittent exposure to CPF, as may be experienced in the real world, on tonic and reflex cardiorespiratory function remains unexplored. Wistar rats were injected with saline or CPF for 4 weeks (3 times/week) or 12 weeks (once/week) at the doses of 7 mg/kg and 10 mg/kg. After exposure, blood pressure (BP), heart rate (HR), respiratory rate (f), tidal volume (V), and minute volume (V) were recorded. Systolic BP and pulse interval (PI) variability, HR spectrum, spontaneous baroreflex and chemoreflex function were also evaluated. Plasma butyrylcholinesterase and brainstem acetylcholinesterase activities were quantified. Enzymatic activity of the CPF animals was reduced after both treatment periods. Baseline BP, HR, and f, as well as systolic BP and PI variability indices, did not change, after CPF treatment. V and V were elevated in CPF animals. CPF exposure increased the very low-frequency component of the HR spectrum. Baroreflex gain was reduced after CPF 4-week exposure. Chemoreflex bradycardia was reduced in the CPF-treated rats. These data show that intermittent exposure to CPF impairs cardiorespiratory function in rats. These results may have important clinical implications for workers seasonally exposed to these compounds.
先前的研究表明，毒死蜱（CPF）急性暴露会损害心肺反射。有证据表明，持续接触有机磷化合物会损害心血管功能。然而，间歇性暴露于 CPF 的影响（如在现实世界中可能经历的那样）对紧张和反射性心肺功能的影响仍未得到探索。Wistar 大鼠接受生理盐水或 CPF 注射，持续 4 周（每周 3 次）或 12 周（每周 1 次），剂量分别为 7mg/kg 和 10mg/kg。暴露后，记录血压（BP）、心率（HR）、呼吸频率（f）、潮气量（V）和分钟通气量（V）。还评估了收缩压和脉搏间隔（PI）变异性、HR 谱、自主血压反射和化学反射功能。测定血浆丁酰胆碱酯酶和脑乙酰胆碱酯酶活性。两种治疗期后 CPF 动物的酶活性均降低。CPF 处理后，BP、HR 和 f 的基线以及收缩压和 PI 变异性指数均未改变。CPF 动物的 V 和 V 升高。CPF 暴露增加了 HR 谱的极低频成分。CPF 4 周暴露后，血压反射增益降低。CPF 处理的大鼠化学反射性心动过缓减少。这些数据表明，间歇性暴露于 CPF 会损害大鼠的心肺功能。这些结果可能对季节性接触这些化合物的工人具有重要的临床意义。
