In ovo embryotoxicity of α-endosulfan adversely influences liver and brain metabolism and the immune system in chickens

There is a lack of laboratory-based embryonic chicken toxicity studies with the ecologically relevant low dose/s of endosulfan that utilizes a more practical approach such as the chorioallontoic membrane (CAM) injection. In this investigation, 2μg AR grade α-endosulfan/egg (40% of LD₅₀ for embryos) was injected through the CAM in 12-day-old chicken embryos and the activities of glucose-6-phosphatase (G6Pase, EC 3.1.3.9), fructose 1,6-diphosphatase (FDPase, EC 3.1.3.11), adenosine triphosphatase (ATPase, EC 3.6.1.3) and succinic dehydrogenase (SDH, EC 1.3.99.1) and DNA and RNA content in liver and brain tissues and acetyl cholinesterase (AChE, EC 3.1.1.7) in the latter were determined at 24, 48, and 72 h post-exposure. The wet weight of the embryos did not differ between groups. Following endosulfan exposure, except increase in the hepatic ATPase activity (P < 0.01), there was a significant decrease in the following parameters: G6Pase activity in both the liver and brain (P < 0.01), SDH activity in the brain (P < 0.01), brain overall DNA and RNA concentration (P < 0.05), brain AChE activity (P < 0.01). Exposure of 18-day-old embryos to 2-μg endosulfan for 24 h caused decrease (P < 0.01) in the lymphocyte count and IgG content. Histopathology of thymus and bursa of Fabricius revealed a reduction in the population of thymic follicles, smaller thymocytes with the clear vacuoles in cytoplasm and fewer bursocytes accompanied by infiltration of erythrocytes in lymphoid follicles of the endosulfan-treated embryos. It was inferred that in ovo injection of 0.041 μg/g egg weight of α-endosulfan suppress gluconeogenesis (main energy source in embryonic life), nerve transmission, and immunity.     

硫丹降解菌的筛选及降解性能研究

从生产硫丹的农药厂的活性污泥中,分离到一株能以硫丹为唯一碳源生长的细菌C7,经鉴定为苍白杆菌属（Ochrobacterum sp．）。构建系统发育树了解C7与其它菌株之间的亲缘关系。用高效液相色谱法对C7的降解性能分析表明,C7在8天内对50mg／L硫丹的降解率达90．2％以上;菌株的培养条件为pH7,温度30℃,接种量25％时测定降解性能最好。     

Resistance of beet armyworm Spodoptera exigua (Lepidoptera: Noctuidae) to endosulfan,organophosphorus and pyrethroid insecticides in Pakistan

Field populations of beet armyworm, Spodoptera exigua (Lepidoptera: Noctuidae), from Pakistan were assessed for their resistance to the chlorinated hydrocarbon endosulfan, the organophosphates chlorpyrifos and quinalphos, and the pyrethroids cypermethrin, deltamethrin, bifenthrin and fenpropathrin. Using a leaf-dip bioassay, resistance to endosulfan was high during 1998–2000 but declined to very low, to low levels during 2001–2007, following a reduced use of the insecticide. Organophosphates and pyrethroids were consistently used over the past three decades, and the resistance had been increasing to these insecticide classes. Generally, the resistance to chlorpyrifos and pyrethroids remained low from 1998 to 2002–2003, but resistance increased to moderate to high levels from 2003–2004 to 2006–2007. For deltamethrin, resistance was very high during 2004–2007. Quinalphos resistance remained low during 1998–2006. Correlation analysis of LC₅₀ and LC₉₀ values showed a positive correlation between organophosphates and pyrethroids, but no correlation between endosulfan and organophosphates or pyrethroids tested herein. These results suggest that the conventional chemistries should be replaced with new chemistries for the successful management of S. exigua.     

Chemical Root-Dips for Control of Root-knot Nematode Attacking Tomato

Abstract

Dimethoate 0.5% for 6 h was the most effective dip for suppressing the root-knot nematode, Meloidogyne incognita (Kofoid and White, 1919) (Chitwood, 1949). It was better than all the other treatments except 0.025% dimethoate for 6 h. Dimethoate at 0.1 and 0.2% and 0.2% parathion and diazinon as 6 h root-dips were phytotoxic. Diazinon controlled the nematode poorly and malathion was ineffective.     

硫丹降解菌C7在土壤中的降解性能及其酶促降解试验

Ochrobactrum sp. C7是一株高效硫丹降解菌。本试验对C7在土壤中降解硫丹的效果以及C7产生的硫丹水解酶(粗酶液)的性质进行了研究。结果表明,该菌在30天内能很好地降解土壤中的硫丹;降解酶在30~45℃、pH5.5~7.5的条件下活性较高;在pH7和40℃时显示最大的硫丹水解酶活性。初步判断水解酶的表达可能是组成型的,此粗酶液可用于果蔬表面农药残留的快速解毒和清除,从而为高效降解菌株的应用与环境中的生物修复提供了理论依据。     

2种农药对葛氏鲈塘鳢外周血红细胞核异常的影响

[目的]研究高效氯氟氰菊酯和硫丹对葛氏鲈塘鳢外周血红细胞核异常的影响,为评价这2种农药对葛氏鲈塘鳢的遗传毒性提供理论依据.[方法]研究不同浓度(0.5、1.0、1.5、2.0μg/L)高效氯氟氰菊酯和不同浓度(1.25、2.50、3.75、5.00、6.25 μg/L)硫丹96h暴露对葛氏鲈塘鳢外周血红细胞核异常率的影响.[结果]随着高效氯氟氰菊酯和硫丹浓度的增加,葛氏鲈塘鳢红细胞的核异常率呈上升趋势,呈现较明显的剂量-效应关系.[结论]高效氯氟氰菊酯和硫丹对葛氏鲈塘鳢具有潜在的遗传毒性,且毒性效应随着农药浓度的增加而增强.     

Acute toxicity of organochlorine insecticide endosulfan and its effect on behaviour and some hematological parameters of Asian swamp eel (Monopterus albus, Zuiew)

In Asia, Monopterus albus (Asian swamp eel) is commonly found in rice fields, muddy ponds and swamp areas. Because of its habitat, it is exposed to toxic pesticides used in rice fields, especially endosulfan, which is one of the most widely used insecticides. This study aims to determine the acute toxicity of endosulfan and its effect on the behaviour and some hematological parameters of the fish. The 96 h-LC₅₀ (with 95% confidence limits) obtained in this study for M. albus was 0.42 (0.35-0.50) μg L⁻¹. After 96 h exposure to endosulfan, the fish exhibited a series of abnormal behavioural responses; these included imbalanced position, restlessness of movement, erratic swimming, tremor, flashing and lethargy. When the swamp eels were exhausted, they were laterally recumbent on the bottom and had no opercula movement. Endosulfan toxicity also caused a significant lower (p < 0.05) value of erythrocyte count, leukocyte count, hemoglobin and hematocrit as compared to the control experiment. Nevertheless, the erythrocyte cell showed an increasing trend in size. The swollen erythrocyte cells may be impaired in their oxygen-carrying capacity. Severe blood loss through the gill capillary and hematemesis of the fish may be the main reasons for the hematological changes in the test organisms. Despite its relatively bigger size (30-40 cm in length) as compared to most of the other test organisms (<5 cm in length) for endosulfan toxicity, it is interesting to find that this fish is one of the most sensitive freshwater fishes to endosulfan.     

Hormone profile of an edible, freshwater teleost, Sarotherodon mossambicus (Peters) under endosulfan toxicity

The hormone profile of Sarotherodon mossambicus (Peters) under endosulfan (an organochlorine pesticide) toxicity was investigated by estimating the serum levels of T₃ (triiodothyronine), T₄ (thyroxine), cortisol, prolactin and insulin in control and sub-lethal (0.001 mg L⁻¹) endosulfan-exposed fish for 1, 6, 12, 24 h and 5 days. Exposure of fish to sub-lethal concentration of endosulfan caused varying changes in the levels of serum hormones studied. Based on the results obtained, it was concluded that (i) the fish registered an increased metabolic activity during the initial period followed by an adaptive lowering of metabolic rate as indicated by changes in the serum T₃ and T₄ levels, (ii) the fish showed an adaptive stress response as indicated by the reduced cortisol level which could be probably due to severe interrenal exhaustion, (iii) the increased serum prolactin levels in the fish under endosulfan exposure is indicative of a possible action of prolactin on gills and kidney towards hydromineral regulation in the fish body under pesticide stress, (iv) the fish adaptively increases its serum insulin level thereby registering a possible adaptive hypoglycemic role of the hormone to favour the transport of glucose to different tissues besides a possible lipogenic activity of the higher insulin level in fish tissue under pesticide toxicity and (v) the fish appears to exhibit a possible adaptive recovery response in its hormone profile following prolonged exposure for 24 h and 5 days.     

Effects of dietary pyridoxine on growth and biochemical responses of Labeo rohita fingerlings exposed to endosulfan

A sixty-day experiment was carried out to study the effect of dietary pyridoxine (PN) on growth performance, RNA/DNA ratio and some biochemical parameters of Labeo rohita fingerlings exposed to sub-lethal dose of endosulfan (1/10th of 96 h static non-renewal LC₅₀ = 0.2 ppb) to assess the role of pyridoxine in ameliorating the negative effects of endosulfan. Two hundred seventy fingerlings (6.5 ± 0.26 g) were randomly distributed into six treatments in triplicates (15 fish/tank). Five iso-nitrogenous (35.45-35.75% crude protein) purified diets were prepared with graded levels of pyridoxine. Six treatment groups were T₀ (10 mg PN + without endosulfan), T₁ (0 mg PN + endosulfan), T₂ (10 mg PN + endosulfan), T₃ (50 mg PN + endosulfan), T₄ (100 mg PN + endosulfan) and T₅ (200 mg PN + endosulfan). Weight gain (%), specific growth rate (SGR), tissue glycogen, and protease activity were significantly (P < 0.05) higher in pyridoxine fed groups compared to their non-pyridoxine fed counterpart. Protease activity was positively correlated (R² = 0.931) with (%) weight gain. Glucose-6-phosphate dehydrogenase (G6PDH) activity was significantly (P < 0.05) higher in non-pyridoxine fed group and decreased in pyridoxine fed counterparts. There were no significant (P > 0.05) effect of dietary pyridoxine on feed conversion ratio (FCR), protein efficiency ratio (PER), survival, gastro-somatic index (GSI), hepato-somatic index (HSI) and liver and muscle DNA levels of L. rohita fingerlings. RNA levels, both in liver and muscle, increased significantly (P < 0.05) in pyridoxine fed groups. A positive correlation was observed between growth and RNA levels, both in liver (R² = 0.91) and muscle (R² = 0.88). RNA/DNA ratio showed a third order polynomial relationship with dietary pyridoxine, both in liver (Y = −0.014x³ + 0.1613x² − 0.5333x + 0.7933, R² = 0.987) and muscle (Y = −0.0407x³ + 0.4763x² − 1.6358x + 2.4667, R² = 0.9345). The overall results obtained in present study indicated that dietary pyridoxine supplementation at 100 or 200 mg PN/kg diet ameliorates the negative effects of endosulfan and restores optimal growth of L. rohita fingerlings.     

2种常用农药对葛氏鲈塘鳢肝脏SOD活性的影响

[目的]探究有机氯和菊酯类农药对葛氏鲈塘鳢抗氧化酶活性的影响,为评价该2类常用农药对葛氏鲈塘鳢的急性毒性效应提供理论依据。[方法]研究了硫丹(1.25、2.50、3.75、5.00和6.25μg/L)和高效氯氟氰菊酯(0.50、1.00、1.50、2.00μg/L)96 h暴露对葛氏鲈塘鳢肝组织超氧化物歧化酶(SOD)活性的影响。[结果]随着硫丹浓度的增加,葛氏鲈塘鳢肝组织的SOD活性表现为先诱导后抑制。高效氯氟氰菊酯各处理组的SOD活性均高于对照组,其中1.50和2.00μg/L处理组的SOD活性显著高于对照组,呈现出明显的浓度效应关系。[结论]硫丹和高效氯氟氰菊酯均可影响葛氏鲈塘鳢肝组织的SOD活性,其变化可作为生物标志物用以评价其对葛氏鲈塘鳢的急性毒性效应。