Comparative evaluation of single and multiple exposure to PM_(2.5)in respirable air on cardiac physiology,structure and function in a Wistar rat model  

作　　者：Bhavana Sivakumar Gino A.Kurian 

机构地区：[1]Vascular Biology lab,School of Chemical and Biotechnology,SASTRA Deemed University,Thanjavur 613401,Tamil Nadu,India [2]School of Chemical and Biotechnology,SASTRA Deemed University,Tirumalaisamudram,Thanjavur 613401,Tamil Nadu,India

出　　处：《Journal of Environmental Sciences》2025年第4期66-77,共12页环境科学学报(英文版)

基　　金：the Indian Council of Medical Research(No.3/1/2(22)/Env/2021-NCD-II);Department of science and technology,India(CRG/2021/000227)for funding this research.

摘　　要：Many studies have shown the negative relationship between long term exposure to PM_(2.5)and cardiac dysfunction.Recently,studies have shown that even a single exposure of PM_(2.5)from air sample in permissible range can induce very mild cardiac pathological changes.In the present study,we revisited the toxic effect of PM_(2.5)on rat heart by adopting single and multiple exposure durations.FemaleWistar ratswere exposed to PM_(2.5)at a concentration of 250μg/m3 daily for 3 hr for single(1 day)and multiple(7,14,21 days)durations.The major pathological changes noted in 21 days exposed myocardium comprised of an elevated ST segment(the segment between the S wave and the T wave),development of cardiac fibrosis,hypertrophy,cardiac injury,tissue inflammation and declined cardiac function.With 14 days exposed heart,the electrocardiograms(ECG),data showed insignificantly declined heart rate and an increased QT(the time from the start of the Q wave to the end of the T wave)interval along with mild fibrosis,hypertrophy and lesser number of TUNEL positive cells.On the other hand,single-and 7-days exposure to PM_(2.5)did not impart any significant changes in the myocardium.To determine the reversibility potential of PM_(2.5)induced cardiotoxicity,a washout period of 24 hours was adopted and all observed changes in the myocardium were reversed till day 7,but not in 14-and 21-days exposed samples.Based on the above findings we concluded that PM_(2.5)associated cardiac dysfunction is the cumulative outcome of ineffective cardiac adaptive and repair process that accumulate additively over the time due to prolonged exposure durations.

关 键 词：PM_(2.5) Diesel particulate matter HYPERTROPHY Cardiac electrocardiogram Single exposure Multiple exposure Cardiac injury 

分 类 号：X513[环境科学与工程—环境工程]