L-精氨酸对凡纳滨对虾体液免疫因子的影响

用添加不同剂量L-精氨酸(L-arg)的饲料投喂凡纳滨对虾(Litopenaeus vannanei),测定其血淋巴液中一氧化氮(NO)含量以及一氧化氮合成酶(NOS)、酸性磷酸酶(ACP)、碱性磷酸酶(AKP)和超氧化物歧化酶(SOD)活力,并检测其对病原体的抗病力.结果显示:L-arg显著提高血淋巴液中NO含量,且变化趋势与NOS、AKP活性升高趋势相一致;中等剂量(质量分数为1%)L-arg显著提高血淋巴液中SOD和ACP活性,但高剂量(质量分数为1.5%)、低剂量(质量分数为0.5%)L-arg对血淋巴液中SOD(高剂量除外)和ACP活性影响不显著.副溶血弧菌人工感染后,中剂量L-arg组(1%)对虾死亡率最低,高剂量(1.5%)、低剂量组(0.5%)次之,对照组死亡率最高,各剂量L-arg组死亡率与对照组相比差异显著.表明饲料中添加适量L-精氨酸可使对虾体液免疫因子总体活力达到较高水平,L-精氨酸含量过高对对虾非特异免疫力的作用效果反而不佳.     

Tyrosinase, a new innate humoral immune parameter in large yellow croaker （Pseudosciaena crocea R）

We evaluated the immune response to infection with a pathogen in large yellow croaker(Pseudosciaena crocea Richardson).The fish were given an intraperitoneal(i.p.) injection of Vibrio parahaemolyticus or sterile sea water(control).We collected blood sera from the fish 0.17,1,2,4,8,12,or 16 d after injection(dpi).We measured tyrosinase activity and the concentrations of lysozyme,NOS,and antibodies.Serum tyrosinase activity was significantly higher at 0.17 and 4 dpi than in the control group,and peaked at 8 d...     

Extract of Meretrix meretrix Linnaeus induces angiogenesis in vitro and activates endothelial nitric oxide synthase

Meretrix meretrix Linnaeus has long been used as traditional Chinese medicine in oriental medicine.The angiogentic activity of the extract of M.meretrix was investigated in this study,using human umbilical vein endothelial cells(HUVECs).Extract of M.meretrix Linnaeus(AFG-25) was prepared with acetone and ethanol precipitation,and further separated by Sephadex G-25 column.The results show that AFG-25 promoted proliferation,migration,and capillary-like tube formation in HUVECs,and in the presence of eNOS inhibitor NMA,the tube formation induced by AFG-25 is inhibited significantly.Moreover,AFG25 could also promote the activation of endothelial nitric oxide synthase(eNOS) and the resultant elevation of nitric oxide(NO) production.The results suggested that M.meretrix contains active ingredients with angiogentic activity and eNOS/NO signal pathway is in part involved in the proangiogenesis effect induced by AFG-25.