农药丙溴磷对人红细胞的毒性效应

目的：探讨农药丙溴磷对正常人红细胞的毒性效应。方法：采用Ｂｉａｌｓｃｈｅ试剂法检测红细胞膜唾液酸（ＲＢＣｍ－ＳＡ）,化学比色法测定红细胞膜Ｃａ２＋－ＡＴＰ酶和全血中谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）。结果：丙溴磷浓度在２×１０－４ｍｏｌ／Ｌ时,可明显降低ＲＢＣｍ－ＳＡ含量,并呈剂量－反应关系。丙溴磷浓度在２×１０－３ｍｏｌ／Ｌ时,红细胞膜Ｃａ２＋－ＡＴＰ酶和全血ＧＳＨ－Ｐｘ明显受抑制,其受抑制程度基本同ＲＢＣｍ－ＳＡ降低呈平行关系。结论：丙溴磷对红细胞的毒性效应与ＲＢＣｍ－ＳＡ的代谢障碍有关。     

土壤中丙溴磷含量测定及残留动态研究

目的：弄清田间喷洒丙溴磷后在土壤中的残留及降解规律。方法：采用GC—FPD法测定田间喷洒丙溴磷后，不同天数丙溴磷在土壤中的残留量。结果：丙溴磷在土壤中的最低检出浓度为0．04mg／kg。加标回收率在95．2％--98．7％范围内，变异系数3．4％--4．5％。按推荐量施药，丙溴磷在土壤中降解符合一级动力学，半衰期为1．09d。施药后13d丙溴磷在土壤中降解率为98．3％。结论：测定方法简便、快速、准确、实用。丙溴磷在土壤中的降解较迅速，对土壤污染较轻。     

Profenofos induced biochemical alterations and in silico modelling of hatching enzyme,ZHE1 in zebrafish (Danio rerio) embryos

The current study was aimed to investigate the oxidative stress response in zebrafish embryos exposed to sub-lethal (LC₁₀) and lethal (LC₅₀) concentrations of profenofos for 96-h and in silico modelling of zebrafish hatching enzyme, ZHE1 to explain the delayed hatching. Embryos exposed to profenofos under semi-static conditions significantly diminished glutathione (GSH), superoxide dismutase (SOD) and glutathione reductase (GR) levels, but increased the activities of catalase (CAT) and glutathione S-transferase (GST) concomitantly with marked elevation in malondialdehyde (MDA) content in whole-body homogenate of the treated groups compared with control. In addition, stress protein Hsp70 expression and DNA damage were significantly increased in a concentration- dependent manner compared with controls. From the computational docking studies of ZHE1 with profenofos revealed that profenofos is binding to three amino acids, histidine 99, histidine 109 and arginine 182 at the active site of the enzyme through hydrogen bonding which may lead to inhibition of hatching.     

Sub-lethal effects of profenofos on tissue-specific antioxidative responses in a Euryhyaline fish, Oreochromis mossambicus

The euryhaline fish, Oreochromis mossambicus was exposed to sub-lethal concentration (30 μg/L) of profenofos (PF) for 28 days and allowed to recover for 7 days. Responses were evaluated through antioxidant enzyme activities in various tissues of fish. Glutathione-S-transferase (GST) and superoxide dismutase (SOD) activities showed transient increases in gill, viscera and muscle, but decreased in brain. However, catalase (CAT) and glutathione reductase (GR) were inhibited in gill and viscera. Reduced glutathione (GSH) levels were depleted in all the tissues and a significant induction in lipid peroxidation (LPO) was observed. Significant recovery in all the studied parameters was noticed at the end of recuperation period. The enhanced LPO in the present study suggests that reactive oxygen species (ROS)-induced oxidative damage could be one of the main toxic effect of PF. The increased LPO and alterations in the antioxidant defense system can be used as biomarkers in the pesticide-contaminated aquatic streams.     

Testicular toxicity of profenofos in matured male rats

To investigate the effect of the phosphorothoate insecticide profenofos on male specific gene expression on rat testis, 16-week-old Wistar rats were orally administered at dose of 17.8 mg/kg twice weekly for 65 days. Gene expression in the testes was monitored by DNA microarray analysis and real-time RT-PCR, which revealed that genes related to steroidogenesis including cytochrome P450 17A1 (CYP17A1), steroidogenic acute regulatory protein (StAR) and CYP11A1 were significantly increased. Besides the testes were histopathologicaly examined, which revealed testicular destruction and degeneration represented by a layer of columnar epithelium, oedematous changes surrounding the seminiferous tubules besides vacuolated spermatogonial cells and more elongated Leydig cells. These data suggest that profenofos considered as one of the male reproductive toxicants. Furthermore, we propose that the above three steroidogenic-related genes and the gene of acrosomal reaction as potential biomarkers of testicular toxicity.     

Longitudinal assessment of occupational exposures to the organophosphorous insecticides chlorpyrifos and profenofos in Egyptian cotton field workers

Chlorpyrifos (CPF) and profenofos (PFF) are organophosphorus (OP) insecticides that are applied seasonally in Egypt to cotton fields. Urinary trichloro-2-pyridinol (TCPy), a specific CPF metabolite, and 4-bromo-2-chlorophenol (BCP), a specific PFF metabolite, are biomarkers of exposure, while inhibition of blood butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) activities are effect biomarkers that may be associated with neurotoxicity. Urinary TCPy and BCP and blood BChE and AChE activities were measured in 37 adult Egyptian Ministry of Agriculture workers during and after 9–17 consecutive days of CPF application followed by an application of PFF (9–11 days), and a second CPF application (5 days) in 2008. During the OP applications, urinary TCPy and BCP levels were significantly higher than baseline levels, remained elevated following the application periods, and were associated with an exposure related inhibition of blood BChE and AChE. Analysis of blood AChE levels before and after the PFF application period suggests that individual workers with peak BCP levels greater than 1000 μg/g creatinine exhibited further inhibition of blood AChE with PFF application, demonstrating that PFF exposure had a negative impact on AChE activity in this highly exposed worker population. While large interindividual differences in exposure were observed throughout this longitudinal study (peak urinary BCP and peak TCPy levels for individuals ranging from 13.4 to 8052 and 16.4 to 30,107 μg/g creatinine, respectively), these urinary biomarkers were highly correlated within workers (r = 0.75, p < 0.001). This suggests that the relative exposures to CPF and PFF were highly correlated for a given worker. The variable exposures between job classification and work site suggest that job title and work location should not be used as the sole basis for categorizing OP exposures when assessing neurobehavioral and other health outcomes in Egyptian cotton field workers. Together, these findings will be important in educating the Egyptian insecticide application workers in order to encourage the development and implementation of work practices and personal protective equipment to reduce their exposure to CPF and PFF.     

丙溴磷对人红细胞膜的毒性作用

为探讨丙溴磷对人红细胞膜的毒性作用,检测了红细胞膜Ⅰ型补体受体(Em-CR1)免疫粘附肿瘤细胞活性与红细胞超氧化物歧化酶(E-SOD)活性、红细胞膜唾液酸(Em-SA)含量以及红细胞膜脂流动性.结果发现,一定浓度丙溴磷可使上述各项指标显着降低,并呈现剂量-效应关系,提示丙溴磷对人红细胞膜有明显的毒性作用     

INFLUENCE OF TEMPERATURE AND DISSOLVED OXYGEN ON THE ACUTE TOXICITY OF PROFENOFOS TO FATHEAD MINNOWS (PIMEPHALES PROMELAS)

ABSTRACT

The purpose of this study was to investigate the influence of temperature and dissolved oxygen levels on the acute toxicity of profenofos to fathead minnows (Pimephales promelas). Exposure conditions were as follows: normal temperature and normal dissolved oxygen (NTNO; 20 ± 2°C and 6.0–9.0 mg/L, respectively); normal temperature and low dissolved oxygen (NTLO; 20 ± 2°C and 1.7–2.6 mg/L, respectively); high temperature and normal dissolved oxygen (HTNO; 30 ± 2°C and 6.6–6.9 mg/L, respectively); high temperature and low dissolved oxygen (HTLO; 30 ± 2°C and 1.5–3.0 mg/L, respectively). Initial 96-h acute toxicity studies with profenofos were conducted at NTNO and HTLO exposure conditions. The 96-h LC₅₀ at NTNO was 333 µg/L with 95% confidence limits ranging from 244 to 558 µg/L. However, the 96-h LC₅₀ at HTLO was significantly lower at 21.5 µg/L with 95% confidence limits ranging from 17.4 to 28.8 µg/L. Acetylcholinesterase (AChE) activity was measured in the head and torso of surviving fish at 96-h. A weak dose-related decrease in AChE was observed at NTNO but no dose–response relationship was observed at HTLO exposure condition. Additional experiments were conducted using 50 µg/L profenofos at NTNO, NTLO, HTNO, and HTLO exposure conditions. Mortality, sublethal effects (erratic and hyperactive swimming), and AChE activity in the head and torso were measured at 2, 4, and 12-h following exposure to profenofos. No mortality or significant sublethal effects were observed in controls or profenofos-treated groups in NTNO and NTLO exposure conditions. However, significant mortality and sublethal effects were observed in profenofos-treated fish in HTNO at 12 h and at all time points in HTLO. Both high temperature and low dissolved oxygen, as well as combinations of high temperature and low dissolved oxygen significantly decreased AChE activity in control fish. Exposure to 50 µg/L profenofos in all exposure conditions further decreased AChE activity, but no apparent correlations between mortality and AChE activity were observed. These results suggest that the acute toxicity of profenofos to fathead minnows may be exacerbated during summer conditions in southern U.S. aquatic ecosystems.     

血中丙溴磷的测定及包膜活性炭和HA230树脂的灌流清除百分率

目的探讨包膜活性炭和HA230树脂对丙溴磷的灌流清除百分率，并比较其清除效果。方法分别用包膜活性炭和HA230树脂对中毒血样进行灌流吸附，将吸附后血样经乙酸乙酯萃取后，用毛细管气相色谱法检测并计算清除百分率。结果分析方法的检出限为0．8ng，低、中、高3种浓度的加标回收率为95．1％～101．2％，相对标准偏差为1．11％-10．97％。灌流吸附后血中丙溴磷的清除百分率在包膜活性炭为78．2％-85．8％，在HA230吸附树脂为84．5％-93．8％。结论用包膜活性炭和HA230树脂吸附剂进行血液灌流，均能迅速降低血中丙溴磷浓度。