Li Y, Lovell R T
J Nutr. 1985 Jan;115(1):123-31. doi: 10.1093/jn/115.1.123.
Channel catfish fingerlings were fed purified diets containing 0 to 3000 mg/kg of ascorbic acid until external signs of scurvy were seen in the fish fed the ascorbic acid-deficient diet. At this time, resistance to bacterial infection, antibody production, complement activity and phagocytic activity were assessed for fish from the various dietary treatments. Mortality rates of fish experimentally infected with Edwardsiella ictaluri, the bacterium causing enteric septicemia in channel catfish, decreased with increases in dietary ascorbic acid doses, ranging from 100% for fish fed the ascorbic acid-deficient diet to 15% for fish fed 300 mg ascorbic acid per kilogram diet and 0 for fish fed 3000 mg ascorbic acid per kilogram diet. Antibody response to E. ictaluri antigen, hemolysis of sensitized sheep erythrocytes by complement activity and phagocytic engulfment of E. ictaluri by peripheral phagocytes were each impaired in fish fed the diet without supplemental ascorbic acid; intracellular bactericidal activity of the phagocytes was not affected by ascorbic acid deficiency. There were no differences in antibody production, complement activity, or phagocytic activities among fish fed diets containing 30-300 mg ascorbic acid/kg of diet. However, the dose level of 3000 mg ascorbic acid/kg significantly enhanced antibody production and complement activity.
斑点叉尾鮰鱼苗被投喂含0至3000毫克/千克抗坏血酸的纯化日粮，直至在投喂缺乏抗坏血酸日粮的鱼中出现坏血病的外部症状。此时，对来自不同日粮处理组的鱼评估其对细菌感染的抵抗力、抗体产生、补体活性和吞噬活性。用鮰爱德华氏菌（引起斑点叉尾鮰肠道败血症的细菌）进行实验性感染的鱼的死亡率，随着日粮中抗坏血酸剂量的增加而降低，从投喂缺乏抗坏血酸日粮的鱼的100%，到投喂每千克日粮含300毫克抗坏血酸的鱼的15%，以及投喂每千克日粮含3000毫克抗坏血酸的鱼的0%。在投喂无补充抗坏血酸日粮的鱼中，对鮰爱德华氏菌抗原的抗体反应、补体活性对致敏绵羊红细胞的溶血作用以及外周吞噬细胞对鮰爱德华氏菌的吞噬作用均受损；吞噬细胞的细胞内杀菌活性不受抗坏血酸缺乏的影响。在投喂含30 - 300毫克抗坏血酸/千克日粮的鱼中，抗体产生、补体活性或吞噬活性没有差异。然而，3000毫克抗坏血酸/千克的剂量水平显著增强了抗体产生和补体活性。
