患多子小瓜虫病草鱼的血液指标及心脏病理研究

The heart disease and blood-change in Ctenopharyngodon idella after parasitized Ichthyophthirius multifiliis

通过比较草鱼(Ctenopharyngodon idella)感染多子小瓜虫(Ichthyophthirius multifiliis)前后心脏组织切片及血清中血脂、胆固醇、脂蛋白等含量变化,探究患多子小瓜虫病草鱼的致死原因.结果表明:感染多子小瓜虫后,草鱼低密度脂蛋白含量和高密度脂蛋白含量显著升高,皮质醇含量显著下降(P<0.05),血清中总胆固醇含量、甘油三酯含量有所上升,极低密度脂蛋白下降,但差异不显著(P≥0.05);患病草鱼心率加快、心肌细胞排列疏松、间隙增大、细胞核部分固缩或消失.由此推断,患小瓜虫病草鱼主要引发心脏机能和血液组分的变化,进而导致鱼体死亡.

Ichthyophthirius multifiliis was usually regarded as the pathogen of"white spot disease",which was widely distributed,could rapidly propagate and cause highly lethal,often lead to serious economic losses.Because of the rapid outbreak rate of this disease,how to stabilize the disease in the early stage of the outbreak of this disease quickly and effectively was an urgent problem to be solved.In order to find a quick way to control the disease,experiment was carried out to explore the pathogenic mechanism of Ichthyophthirius multifiliis.Studies showed that in addition to the gills and skin,Ichthyophthirius multifiliis were also found in the body of the sick fish,and when dissecting the sick fish,it was found that the fish′s heart often contains congestion.The cause of death was explored by comparing the pathological changes in heart tissue sections of Ctenopharyngodon idella before and after being parasitized Ichthyophthirius multifiliis,as well as the contents of blood fat and cortisol in serum.The results showed that after being parasitized Ichthyophthirius multifiliis,low density lipoprotein and high density liptein cholesterol increased significantly but cortisol decreased obviously(P<0.05).Meanwhile,total cholesterol and triglyceride in serum increased but very low density lipoproteins de-creased indistinctively(P≥0.05).The infection of Ichthyophthirius multifiliis could cause the heart-rate of Ctenopharyngodon idella to increase,the arrangement of myocardial cells was loose,the gap was enlarged,and the nuclear part was pyknosis or disappearance.The heart-rate of infected Ctenopharyngodon idella was accelerated.Besides,there were found some changes in cardiomyocytes:the arrangements were looser,the gaps were enlarged,and the nuclei were partly pyknosis or disappearance.It could be inferred that the chan-ges in heart function and blood components mainly led to the death of Ctenopharyngodon idella suffering from Ichthyophthirius multifiliis.