Responses of the Indian major carp Labeo rohita to deltamethrin at acute and sublethal concentrations

The effects of deltamethrin at acute and sublethal concentrations on some hematological and biochemical profiles in the Indian major carp Labeo rohita have been examined. The lethal concentrations (LC₅₀) of deltamethrin for 24 and 96 h were found to be 0.44 and 0.38 mg L^?1, respectively. During acute treatment (24 h), hemoglobin (Hb), hematocrit (Hct), red blood cell (RBC), white blood cell (WBC), mean cellular volume (MCV), mean cellular hemoglobin (MCH), and mean cellular hemoglobin concentration (MCHC) values were significantly increased compared to control group. Plasma glucose, protein, cholesterol, albumin, globulin, triglyceride, and glycogen in gill and muscle were significantly decreased. Upon sublethal treatment (0.044 mg L^?1, 10th of 24 h LC₅₀), RBC and the biochemical parameters, except glucose and cholesterol, decreased significantly, while MCV, MCH, and MCHC values increased up to the 28th day and then declined. Cholesterol level was significantly increased throughout the study period. A biphasic response in the levels of Hb, Hct, WBC, and glucose were observed during sublethal treatment.     

Toxic effects of deltamethrin and λ-cyhalothrin on Xenopus laevis tadpoles

This study evaluates the toxic effects of deltamethrin and λ-cyhalothrin on Xenopus laevis tadpoles after 168 h of exposure. The LC₅₀ of deltamethrin and λ-cyhalothrin at 168 h was calculated as the μg of active ingredient per liter (μg AI/L). According to these values, the LC₅₀ was 6.26 and 3.94 μg AI/L for deltamethrin and λ-cyhalothrin, respectively. Several enzymes were studied for early signs of intoxication following exposure to the pesticides for 24 h. Glutathione-S-transferase,carboxylesterase, and lactate dehydrogenase were inhibited by λ-cyhalothrin, and both pesticides inhibited acid phosphatase and aspartate aminotransferase. In contrast, acetylcholinesterase was activated by deltamethrin. The results suggest that X. laevis is sensitive to the pyrethroids that were tested, and the enzyme responses suggest that they are potential biomarkers for evaluating the toxic effect of pyrethroids on amphibians in environmental conditions.     

On‐target deposition of aerially applied deltamethrin

Abstract

The mean amount of deltamethrin deposited on natural substrates (i.e., soil and vegetation) in three experiments was 63, 73, and 76% of applied. Composite samples taken from 16 sites/replicate gave representative and repeatable measures of deposition. The use of Teflon discs as artificial targets to measure aerial deposition was investigated. The discs had only 34–71% mean trapping efficiency for the spray droplets. Deposition was quite variable among different sampling sites within a field (CV=73–83%). Much of this variation was caused by irregular overlapping of spray swaths.     

低浓度溴氰菊酯连续暴露对罗非鱼DNA的影响

运用RAPD技术和外周血嗜多染红细胞微核试验来分析和评价低浓度溴氰菊酯连续暴露对罗非鱼DNA的影响.RAPD试验结果表明,在12个能扩增出罗非鱼基因组DNA的引物中,引物S326能检测出3 μg/L以上浓度溴氰菊酯暴露前后罗非鱼基因组DNA的差异,而小于2.0 μg/L的低浓度溴氰菊酯对罗非鱼基因组DNA没有影响.外周血嗜多染红细胞微核试验结果表明,在一定浓度的溴氰菊酯连续暴露后,2.0 μg/L以下浓度组罗非鱼外周血红细胞微核率与对照组相比没有显著差异(P＞0.05),而3 μg/L以上浓度组可诱导罗非鱼外周血红细胞产生微核.微核率与对照组相比差异显著(P＜0.05),且表现出明显的剂量-效应和时间-效应关系.研究表明,溴氰菊酯在一定条件下可对鱼类DNA产生影响.     

锌离子胁迫下溴氰菊酯对麦穗鱼的急性毒性

以麦穗鱼(Pseudorasbora parva)为试验材料,研究了在一定环境条件下锌离子的胁迫对溴氰菊酯急性毒性的影响.结果表明,水温为(28.5±0.5) ℃时,锌离子对麦穗鱼24～96 h 的LC50值为3.2～13.4 mg/L,溴氰菊酯对麦穗鱼24～96 h 的LC50值为7.2～13.4 μg/L;而水温为(15.5±0.5) ℃时,锌离子对麦穗鱼24～96 h 的LC50值为18.0 mg/L以上,溴氰菊酯对麦穗鱼24～96 h的LC50值为5.6～10.0 μg/L.水温的升高将明显地提高锌离子对鱼类的急性毒性,并降低溴氰菊酯对鱼类的急性毒性.研究同时发现,锌离子在酸性水质中对溴氰菊酯的急性毒性有增强的作用,且这种作用效果随着水温和锌离子质量浓度的上升而更为显著.但在中性及碱性水体中的效果不明显.在急性毒性试验96 h后,锌离子在中、酸性水质中的质量浓度比较稳定,在碱性水质中有一部分损失,表明水中重金属的质量浓度变化比较稳定,主要受水质pH值影响,与温度无关.而溴氰菊酯的质量浓度下降明显,高温高pH值条件下的降解幅度尤为显著,说明水中溴氰菊酯的降解主要受水质pH值与温度的影响.研究显示,锌离子在一定条件下可增强溴氰菊酯的毒性作用,必须在实际生产中注意其联合污染效应.     

Effects of deltamethrin on serum calcium and corpuscles of Stannius of freshwater catfish,Heteropneustes fossilis

Adult male deer mice were exposed every other day for a period of 11 days to either 7,12-dimethylbenzanthracene (DMBA; CAS# 57-97-6) or benzo[b]fluoranthene (BbF; CAS# 205-99-2) (0, 0.3, 1, 3, 10, or 30?mg?kg^?1). Immune endpoints assessed were lymphocyte proliferation, macrophage pinocytosis, and the antibody plaque-forming cell (PFC) response. Cytochrome P450 (CYP450) activity was assessed using ethoxyresorufin-O-deethylase (EROD) and pentoxyresorufin-O-deethylase (PROD). Macrophage pinocytosis was not altered by either compound. Both T- and B-cell proliferations were significantly increased by DMBA at 0.3 or 1?mg?kg^?1 and by BbF at 10 or 30?mg?kg^?1, but decreased by DMBA at 30?mg?kg^?1. Sheep red blood cell (SRBC)-specific-IgM production, as measured by the PFC response, was the most striking adverse immune effect observed and was significantly suppressed compared to control at all treatment concentrations for both compounds. EROD activity was markedly induced by DMBA at 30?mg?kg^?1, while BbF produced induction at 1, 10, or 30?mg?kg^?1. No marked effect on PROD activity was noted following DMBA treatment, but BbF-induced PROD activity at 1, 10, or 30?mg?kg^?1. Unexpectedly, four of six mice in the 30?mg DMBA?kg^?1 group did not survive to the end of the experiment, and one animal died in both the 3 and 10?mg?kg^?1 treatments. The calculated LD₅₀ was 20.8?mg DMBA?kg^?1. The PFC response in deer mice was a more sensitive endpoint than CYP450 activity, suggesting that utilization of CYP450 endpoints in risk assessment without assessment of immune function, specifically antibody production, might possibly underestimate the risk to wild rodents environmentally exposed to polycyclic aromatic hydrocarbons.     

The effect of vitamin E supplementation on ovary and testis histopathology in Oreochromis niloticus exposed to deltamethrin

The effects of deltamethrin on the histology of Oreochromis niloticus testis and ovary and the protective effect of vitamin E supplementation were investigated. The fish were divided into four groups, i.e. a control group, a vitamin-E-treated group, a deltamethrin-treated group and a vitamin E+deltamethrin-treated group. In the control and vitamin-E-treated groups, the ovaries and testes were normal at the end of 7, 14, and 21 days. In the deltamethrin-treated group, deformed oocytes, atretic oocytes, melanomacrophage centers, and focal necrotic areas were noted in the ovaries. Deltamethrin also caused cell necrosis, nuclear pycnosis, decreasing number of spermatogenic cells, decreasing spermatozoa within the lumen of tubule, decreasing number of spermatocyte cells, hypertrophy and degeneration of spermatogonia cells, and increasing number of macrophages in testis. Vitamin E decreased some histopathological changes induced by deltamethrin, but did not confer complete protection.     

Deltamethrin-induced alteration of iron metabolism in Wistar rats

Abstract

The impact of sub-lethal exposure to deltamethrin on the expression of hepcidin, ferroportin and transferrin genes in Wistar rats was studied. A dosage of 30?mg/kg per day for five days was found to modify the hepcidin-ferroportin axis that primarily governs iron homeostasis. Significant variations in erythrocyte, leukocyte, lymphocyte, platelet and monocyte counts, as well as the reduced serum protein profile, suggested anemia. The results collectively demonstrated the novel finding of deltamethrin’s disruptive effect on iron homeostasis.     

溴氰菊酯对罗非鱼谷胱甘肽及S转移酶的影响

研究了罗非鱼暴露于不同浓度溴氰菊酯后,组织中谷胱甘肽(GSH)的含量和谷胱甘肽-S-转移酶(GST)活性的动态变化.结果表明,以1.0,2.0,3.0,5.0,10.0μg/L浓度的溴氰菊酯处理罗非鱼25d,除了1.0μg/L浓度组罗非鱼体内GSH和GST与对照组无显著差异外,其余各浓度组的GSH和GST均发生了明显的变化,规律为先升高后降低,说明溴氰菊酯对罗非鱼体内的GSH和GST是先诱导后抑制,且肝脏的变化幅度比肌肉大.1.0μg/L以下的溴氰菊酯对罗非鱼没有生化毒性影响.罗非鱼组织中的GSH和GST可作为生物标志物来评价农药对鱼类的生化毒性.     

溴氰菊酯农药对鱼塘浮游动物影响的研究

建立稻田－鱼塘模拟生态系统。对稻田施用溴氰菊酯农药后,将含有农药的稻田水排入鱼塘,研究鱼塘中浮游动物受影响情况。结果表明：大多数浮游动物对溴氰菊酯敏感,在该系统中测定的枝角类、桡足类、轮虫和原生动物的EC50－24h值分别为0.18、0.30、2.00及0.66μg/L。含农药的稻田水排入鱼塘后,多数浮游动物现存量显著减少,24h后逐渐恢复,2周后可以恢复至正常水平。未对浮游动物造成持久的、不可逆的毒性效应