饲料碳水化合物水平对南方鲇(Silurus meridionalis)幼鱼肝脏、胰脏和肾脏的组织学影响

为研究饲料碳水化合物对南方鲇（Silurus meridionalis）的组织结构的影响,配制分别含0%,15%,30%糊化玉米淀粉的等能饲料分别作为对照、中水平和高水平碳水化合物（CHO）饲料,观察以3种饲料喂养8周后南方鲇鱼体肝脏、胰脏和肾脏的组织形态学.结果发现：中水平碳水化合物和高水平碳水化合物组的肝细胞多发生肿胀和空泡化,部分肝细胞膜破裂.中水平碳水化合物和高水平碳水化合物组的肝细胞密度差异不显著,二者均显著低于对照组（p〈0.05）.高水平碳水化合物组肝细胞短径显著大于对照组（p〈0.05）,二者均与中水平碳水化合物组无显著差异.中水平碳水化合物和高水平碳水化合物组肝细胞核多移至细胞边位,大小无明显变化.中水平碳水化合物和高水平碳水化合物组的胰脏和肾脏组织结构与对照组相比没有明显变化.结果表明：摄食过高水平碳水化合物饲料对南方鲇幼鱼的肝脏组织结构有一定程度的损害,验证了饲料碳水化合物对肉食性鱼类在组织学水平上的营养胁迫.

Effect of Dietary Carbohydrate Level on Histology of Liver, Pancreas and Kidney in the Southern Catfish (Silurus meridionalis) Juveniles

To study the effect of dietary carbohydrate(CHO)on the histological structure in the southern catfish(Silurus meridionalis),the morphological structures of the liver,pancreas and kidney were examined in the fish,fed with diet containing 0%(control),15%(middle-level CHO)and 30%(high-level CHO)gelatinized corn starch,respectively.The feeding experiment lasted for 8 weeks in the recirculated water system.The results showed that compared to the control group,most of the hepatocytes in the fish at middle-and high-CHO levels were swelling and vacuolating,and part of the hepatocyte membrane was broken.Hepatocyte densities at middle-and high-CHO levels were significantly lower than that in the control group,while no significant difference was found between the former two groups.The short diameter of the hepatocytes of the high-CHO group was significantly longer than that in the control group,while compared with middle-level group,no significant difference was observed in the former two groups.Most of the nuclei shifted to the periphery of the hepatocytes at middle-and high-CHO levels.No evident changes were observed in the histological structures of pancreas and kidney among the three groups.These results showed that the histological structure of liver was damaged to a certain extent by excess dietary CHO,which indicated a nutritional stress of dietary CHO on carnivorous fish at the histological level.