Investigation of the leptin levels in the blood serum of Cyprinus carpio (Linnaeus, 1758) and Capoeta trutta (Heckel, 1843)

Leptin is a peptide hormone secreted by adipose tissues in the various teleost fish and vertebrates. Leptin has been suggested to have an important role in a range physiological function, including regulation of food intake, reproduction, immune function, energy expenditure, lipid and carbohydrate metabolism. In this study, leptin levels in the blood serum of Cyprinus carpio and Capoeta trutta were determined. Then the results were compared between two species and between sexes of each species. In addition, leptin levels were also compared with the body weight and length of both C. carpio and C. trutta. Leptin level was analysed using available enzyme‐linked immunoassay (ELISA) kit (Rat leptin ELISA kit, catalog no: SK00050‐08). Leptin levels showed no significant difference (p > 0.05) that in relation to between two species and between sexes of each species. It has been shown that not significantly correlated when examined correlations between the leptin level in blood serum and body weight (r = 0.192, p = 0.380) or length (r = 0.102, p = 0.644) of C. carpio. Similarly, the correlations between leptin level in blood serum and body weight (r = 0.021, p = 0.959) or length (r = 0.123, p = 0.595) of C. trutta were also not significant.     

Toxicological effects and recovery of the corneal epithelium in Cyprinus carpio communis Linn. exposed to monocrotophos: an scanning electron microscope study

This study was conducted based on the evidence of fish habitats in North India being affected by organophosphate pesticides draining from agricultural fields into bodies of water, especially during the rainy season. Various tissues of fish such as scales, gills ovaries, kidney, and liver have been studied from the toxicological point of view, but the toxicological effects of aquatic pollutants on fish cornea have not been investigated to date. We conducted comparative toxicological studies on the cornea of Cyprinus carpio communis using two sublethal (0.038 and 0.126 ppm) concentrations of monocrotophos pesticide for 30 days. Corneas from all the groups were evaluated by a scanning electron microscope. The fish exposed to the monocrotophos pesticide developed corneal necrosis due to the formation of crystalloid‐like structures, thinning and shrinkage of microridges on the corneal epithelium. After 30 days, fish from the monocrotophos‐treated tank were transferred to normal environmental conditions. After 60 days under natural condition, epithelial cells did not fully recover. In conclusion, exposure to monocrotophos induces irreversible changes in the cornea of C. carpio communis. As fish and mammalian visual systems share many similarities, the reported finding may offer useful insights for further toxicological and ophthalmological studies in humans.     

鲤春病毒血症病毒(SVCV)的研究进展

鲤春病毒血症病毒（SVCV）是一种能够引起鲤科鱼类急性传染性病毒病-鲤春病毒血症（SVC）的病原，一旦暴发会造成巨大的经济损失。该病主要在欧洲的鲤鱼养殖中广泛传播，主要症状为体内出血，腹膜炎及腹水。SVCV具有囊膜，暂时列为弹状病毒科水泡性病毒属。病毒基因组为线性单股不分段的负链RNA，长11019个核苷酸，主要包含5个基因，分别编码核蛋白N、磷蛋白P、基质蛋白M、糖蛋白G和RNA聚合酶L。日前，中国出入境检验检疫检测SVCV的行业标准是逆转录PCR法。本研究从病毒的生物学特征，感染的临床症状及流行特点，病毒基因组及其多肽特征，病毒的分类地位以及检测技术等方面对国内外研究的现状作一综述，以期为研究者提供理论参考。     

鲤病毒病原的感染性测定

为查明养殖鲤（Cyprinus carpio）突然大批发病死亡的原因，对鲤病样品进行了细胞攻毒、空斑测定、电镜观察，以及鱼体感染等实验。先以患病鲤的组织匀浆液，经过滤后，分别接种到草鱼鳍条细胞（GCF）、鲤上皮瘤细胞（EPC）等14种培养细胞中。利用倒置显微镜观察显示，在1-2d内，该病鱼组织匀浆液可使其中9种细胞出现典型的细胞病变。收集出现病变的细胞液（即病毒悬液），进一步进行病毒滴度检测、空斑测定和鱼体感染实验。结果显示，在GCF细胞上的病毒滴度为10^7.3TCID50／mL；在FHM，TSB和GCO等细胞中可产生直径1～4mm的圆形空斑，空斑的大小与宿主细胞的种类和接种的病毒浓度有关。通过对感染细胞制备的超薄切片和病毒负染样品进行电镜观察，显示这是一类呈典型子弹头样的弹状病毒颗粒。感染了病毒悬液的鲫和鲤先后在第2天和第3天开始出现病症，间隔1～2d后发病的鱼开始死亡，至第14天，两种感染鱼的死亡率均达到83．3％。收集人工感染后濒死的鲫和鲤，分别制备组织匀浆液，回接感染鱼类培养细胞，24h内能使其出现与原发病鲤组织匀浆液所引起的类似的细胞病变。因此证实患病鲤是由病毒病原感染所致。[中国水产科学，2006，13（4）：617—623]     

散鳞镜鲤、团头鲂及其杂交F1肌肉营养成分的比较

采用生化分析方法对散鳞镜鲤、团头鲂及其杂交F1肌肉的营养成分进行了测定并比较。结果表明，交杂种F1肌肉中的水分含量为77．89％、灰分含量为5．52％，均低于亲本；脂肪含量为4．77％，高于团头鲂，低于散鳞镜鲤；F1的氨基酸含量为77．89％，低于双亲，但大多成分含量与散鳞镜鲤相当。在总体水平上，杂交种品质得到初步的改良。     

鲤鱼单极虫病组织病理研究

本文报道了1989年以来,造成王快水库等网箱养鲤大批死亡的单极虫病,病鱼出现烂鳃、肛门红肿、腹部膨大,腹腔内有大量粘液等症状;显微观察的结果为:各组织器官发生病变,肠上皮细胞严重坏死,平滑肌纤维发生玻璃样变及解体,鳃丝充血,鳃小片融合,肝细胞核溶解、坏死。     

喹乙醇对鲤鱼的急性毒性试验

以一龄越冬的德国镜鲤为试验对象，测定一次内服和腹注喹乙醇96h的死亡率，探讨喹乙醇对鲤鱼的毒性作用。试验结果表明，2－10g/kg体重的等比浓度梯度喹乙醇内服剂量不引起任何毒性反应，腹注喹乙醇LD50为1022.6mg/kg。结果提示，喹乙醇对鲤鱼的毒性极低。     

外源基因导入鲤（Cyp rinus carpio）受精卵最佳时期的研究

本研究以鲤鱼受精卵为材料，通过显微注射技术，在受精卵的不同发育时期把鲤鱼ＭＴ启动子基因和大麻哈鱼ＧＨ基因导入受精卵中，按孵出的鱼苗数分别计算成活率，再通过斑点杂交和Ｓｏｕｔｈｅｒｎ Ｂｌｏｔ杂交检测整合情况，计算整合率，孵化率最高的为单细胞中期（９０．８３％），整合率最高的为单细胞后期和囊胚期（４０％）。综合研究结果外源基因导入鲤鱼受精卵的最佳时期应选在单细胞后期。     

红鲤4群体间红细胞免疫功能及其差异

应用红细胞C3b受体花环试验和红细胞天然免疫粘附肿瘤细胞花环试验方法，证实兴国红鲤(Cyprinuscarpio.var.singguonensis)、玻璃红鲤(C.carpio.var.wananensis)、荷包红鲤(C.carpio.var.wananensis)及瓯江彩鲤(C.carpio.var.color)的红细胞表面都存在C3b补体受体，均可形成花环；红鲤的红细胞免疫粘附能力存在着种群间差异，上述2种花环试验的花环率大小的顺序均是：兴国红鲤＞荷包红鲤＞瓯江彩鲤＞玻璃红鲤，差异都极显著(P＜0．01)；4群体红鲤的红细胞均具有吞噬作用。结果证实，鱼类红细胞免疫功能在机体防御病原的过程中占有重要地位。     

锦鲤暴发性出血症病原的研究

从患暴发性出症的锦鲤体内分离出2株细菌－052202和052203，应用细菌分离鉴定方法和法国Biomerieux FRC公司的API全自动微生物鉴定系统进行鉴定，结果显示：052202株为嗜麦芽窄食单胞菌（Stenotrophomonas maltophilia),052203株为温和气单胞（菌（Aeromonas sobria)。生物毒性试验的结果表明，温和气单胞菌可使健康锦鲤死亡，引起体表出血，肝，肾，脾，胆囊发生病变，有致病性；而嗜麦芽窄食单胞菌不引起健康锦鲤死亡，无致病性，28例药物的药敏试验结果表明，温和气单胞菌对新霉素，卡那霉素，庆大霉素，头孢噻吩，头孢曲松的头孢他啶的敏感性强或较强。