Banerjee B D, Koner B C, Ray A
Department of Biochemistry, University College of Medical Sciences (University of Delhi), India.
Indian J Exp Biol. 1996 Aug;34(8):723-33.
In recent years, great concern has been expressed about genotoxic potential of pesticide chemicals. These toxic chemicals have become an integral part of the ecosystem and the human health effects of these agents are yet to be satisfactorily defined. The objectives of this review is to examine the sources of information available; evaluation of experimental protocols employed for assessment of immunological effects; and to study specific cellular and molecular locus which could be responsible for impaired immune responsiveness. It is emphasized that threshold level for the pesticide effect below which no effect would be seen, depends on the animal species, the method of testing for immune responses and type of antigen used. A comparative assessment of immune responses using different antigens is, therefore, an important aspect of pesticide immunotoxicity. In view of widespread use, distribution and stability of some of these compounds in the environment, pesticide exposure may play a greater role in suspected fragile immune system, and may result in altered disease susceptibility. An understanding of these risks depends, to a great extent, upon cellular and molecular events underlying pesticide-induced immune alterations in experimental animals. It is, therefore, proposed that pesticide chemicals may influence humoral immunity while having no detectable effect on cell-mediated immunity (CMI); immune dysfunction is related to dose and duration of pesticide exposure; a single assay of immune function may not be appropriate to detect pesticide-induced immune dysfunction; since many immune responses are genetically controlled, alterations in responsiveness to one challenge in a given animal model may not hold true in second one; although it has been established that pesticide chemicals can alter immune function, the mechanisms of action have yet to be determined. This paper also reviews the effects of pesticide on lymphocyte function and suggests that lymphocyte dysfunction may be an integral part of pesticide-induced immunosuppression and presents an approach which may serve to delineate the possible mechanisms of action. It is quite clear that pesticide-induced immunomodulation endangers humans and animals. This hazard should, therefore, not to be underestimated in evaluation of toxicity of these chemicals. However, additional research is needed in basic mechanism of immunotoxicity and identification of susceptibility factors which predispose to these reactions.
近年来，人们对农药化学品的遗传毒性潜力表示了极大关注。这些有毒化学品已成为生态系统的一个组成部分，而这些物质对人类健康的影响尚未得到令人满意的界定。本综述的目的是检查可用的信息来源；评估用于评估免疫效应的实验方案；并研究可能导致免疫反应受损的特定细胞和分子位点。需要强调的是，农药效应的阈值水平（低于该水平则无效应）取决于动物物种、免疫反应的测试方法以及所用抗原的类型。因此，使用不同抗原对免疫反应进行比较评估是农药免疫毒性的一个重要方面。鉴于其中一些化合物在环境中的广泛使用、分布和稳定性，农药暴露可能在疑似脆弱的免疫系统中发挥更大作用，并可能导致疾病易感性改变。对这些风险的理解在很大程度上取决于实验动物中农药诱导的免疫改变所涉及的细胞和分子事件。因此，有人提出农药化学品可能影响体液免疫，而对细胞介导免疫（CMI）没有可检测到的影响；免疫功能障碍与农药暴露的剂量和持续时间有关；单一的免疫功能检测可能不适用于检测农药诱导的免疫功能障碍；由于许多免疫反应是由基因控制的，在给定动物模型中对一种刺激的反应性改变在另一种模型中可能不成立；尽管已经确定农药化学品可以改变免疫功能，但其作用机制尚未确定。本文还综述了农药对淋巴细胞功能的影响，并表明淋巴细胞功能障碍可能是农药诱导的免疫抑制的一个组成部分，并提出了一种可能有助于描述其可能作用机制的方法。很明显，农药诱导的免疫调节对人类和动物都有危害。因此，在评估这些化学品的毒性时，不应低估这种危害。然而，在免疫毒性的基本机制以及易引发这些反应的易感因素的识别方面，还需要进一步的研究。
