Nayak S K, Swain P, Nanda P K, Dash S, Shukla S, Meher P K, Maiti N K
Fish Health Management Division, Central Institute of Freshwater Aquaculture, Kausalyaganga-751 002, Bhubaneswar, Orissa, India.
Fish Shellfish Immunol. 2008 Apr;24(4):394-9. doi: 10.1016/j.fsi.2007.09.005. Epub 2007 Oct 5.
Endotoxin, a lipopolysaccharide component of outer cell wall membrane of the Gram-negative bacteria is a factor responsible for a number of biological effects including immunostimulatory activities in different animal species including fish. In this study, L. rohita yearlings of weight ranging from 80 to 100g were injected intraperitoneally with 0.5, 1, 2, 5, 10 and 20 EU/fish dose of endotoxin to find out its effect on the immunity. The L. rohita yearlings were found to resist the endotoxin dose up to 20 EU/fish and at the lower doses, i.e., at 1 and 2 EU/fish; it acted as an immune potentiator. Different serum and immune parameters like protein, globulin, lysozyme, respiratory burst activity, myeloperoxidase activity, natural agglutination titre were found to be significantly high (p<0.01) at a dose of 1 EU/fish. While at 10 and 20 EU/fish, most of these parameters were lower thereby indicating the immuno-suppressive nature of the endotoxin at these higher doses.
内毒素是革兰氏阴性菌外细胞壁膜的一种脂多糖成分，是导致多种生物学效应的一个因素，这些效应包括在包括鱼类在内的不同动物物种中的免疫刺激活性。在本研究中，给体重在80至100克之间的当年生印度鲤幼鱼腹腔注射0.5、1、2、5、10和20 EU/鱼剂量的内毒素，以探究其对免疫的影响。发现当年生印度鲤幼鱼能够抵抗高达20 EU/鱼剂量的内毒素，在较低剂量，即1和2 EU/鱼时，它起到免疫增强剂的作用。发现不同的血清和免疫参数，如蛋白质、球蛋白、溶菌酶、呼吸爆发活性、髓过氧化物酶活性、自然凝集滴度，在1 EU/鱼剂量时显著升高（p<0.01）。而在10和20 EU/鱼剂量时，这些参数大多较低，从而表明内毒素在这些较高剂量时具有免疫抑制性质。
