Effect of dietary supplementation with flaxseed oil or vitamin E on sheep experimentally infected with Fasciola hepatica

The effects of two diets supplemented with flaxseed oil (FO) or vitamin E (VE) were studied in sheep infected with Fasciola hepatica. The control group (CO), not supplemented, had higher weight gain and faecal egg count (P < 0.05) at the end of the study. At necropsy, the number (71.2 ± 26.5) and size of flukes were lower in the FO group (P < 0.01), probably due to the higher levels of white blood cells and lymphocytes (P < 0.01). This group also had higher red blood cell and haematocrit values (P < 0.01). The CO group had more severe hypoproteinaemia and hypoalbuminaemia, due to having the highest fluke burden (123.0 ± 35.2), and also the highest IgG1 titre (P < 0.01). The diet did not affect production or gene expression levels of IFN-γ and IL-4. On the other hand, the supplementation with VE led to a reduction in adult fluke burden (97.7 ± 39.9) and lower lipid oxidation in the liver (P < 0.001).     

Changes of the Levels of Blood NO and TNF-α Concentrations in Water Buffaloes and Goats Infected with Fasciola hepatica

Changes of concentrations were studied in water buffaloes and goats infected with Fasciola he-patica on blood NO(nitric oxide) and TNF-α(tumor necrosis factor-α). Twenty healthy male castrated waterbuffaloes of 2 - 3 years old and weighing 300 - 500 kg as well as six goats were confirmed free of fasciolosis byfecal examination and Dot-ELISA. Two studies were conducted using the water buffaloes. In the first experi-ment, 8 water buffaloes were randomly divided into control group (n=3) and infection group (n=5). Eachbuffalo in the infected group received orally 60 metacercariae of F. hepatica per day for 20 days (total 1 200metacercariae) to produce a chronic infection. In the second experiment, 12 water buffaloes were randomly di-vided into infected (n=9) and control group (n=3). Each buffalo in the infected group was given a singleoral dose of 1 600 metacercariae to produce an acute infection. The 6 goats were randomly divided into two in-fected groups and a control group. The sheep in two infections received a single oral dose of 200 and 500 meta-cercariae respectively, the control group remained uninfected. Blood NO and TNF-α concentrations of the testanimals were measured by a reductive enzyme assay and RIA, respectively. Blood NO concentration in bothacutely and chronically infected water buffaloes progressively increased from week 3 post-infection and was sig-nificantly greater than that of the control group (P＜0.05) at the 5th week (acute infection) and 7th week(chronic infection), and remaining at higher concentration for the remaining period of the studies. BloodTNF-αt concentrations in both chronically and acutely infected water buffaloes also increased after infection. Inthe goat experiment, plasma NO concentrations in both infection groups increased from week 3 after infection,and remained higher than that of the control group until the end of the experiment. TNF-α concentrations ingoats in infection group 1 and 2 gradually increased after infection and were significantly greater than those ofthe control group from the 9th to 11th week and from the 11th to 15th week respectively.     

牛肝片形吸虫体内5-HT样物质的研究

用荧光分光光度法和色谱法对牛肝片形吸虫体内的5-HT样物质进行了定性、定量研究。结果表明此虫体内的5-HT样物质与OPT反应后,其激发光谱和发射光谱与标准5-HT与OPT反应产物的光谱一致。另外,用小白鼠脑组织提取物作为“生物标准物”与吸虫提取物进行对照,两者通过同一凝胶柱(SephadexG-10,7—10×40mm)的色谱特性非常相似。用Curzon法测得肝片形吸虫全虫的5-HT含量为0.512±0.09μg/g湿重,“头”部略高于“尾”部。将吸虫置于Rohrbacher溶液中培养,加5-HTP时,虫体5-HT含量明显上升,而色氨酸则不能使5-HT含量增加。肝片形吸虫对外界环境中的5-HT有摄取能力,培养液中5-HT浓度在10~(-5)M时可使虫体内的5-TH提高到4.88倍。5-HT颉颃药赛庚啶不能降低内源性5-HT的量,但能抑制此吸虫体对外源性5-HT的摄取;色氨酸羟化酶抑制剂对氯苯丙氨酸不能改变内源性5-HT的含量。