饲料维生素A对美国红鱼组织NO的影响

Effects of dietary vitamin A levels on tissue nitric oxide of red drum(Sciaenops Ocellatus)

采用单因子试验设计,将300尾平均体重为151.46(±8.18)g的美国红鱼随机分为5个处理,每个处理3个重复,每个重复20尾,分别饲喂5种不同维生素A水平(30、4 166、8 533、18 532、33 263 IU/kg)的等氮等能饲料,进行为期8周的生长试验。结果表明:饲料维生素A水平在33 263 IU/kg时美国红鱼头肾和脑的NO含量和NOS活力最高;饲料维生素A水平在8 533IU/kg时美国红鱼脾的NO含量和NOS活力最高;饲料维生素A水平在18 532 IU/kg时美国红鱼肠的NO含量和NOS活力最高;饲料维生素A水平在4 166 IU/kg时美国红鱼胸腺的NO含量和NOS活力最高;饲料中添加维生素A对美国红鱼肝脏的NO含量和NOS活力影响不显著。综上所述,饲料中添加适当维生素A对美国红鱼组织中的NO含量和NOS活力有显著影响。

Five iso-nitrogenous and iso-energetic diets were formulated to contain graded level of vitamin A （30, 4 166, 8 533, 18 532 and 3 3263 IU/kg diet, respectively ） and fed to 15 floating netcages with about 20 fish （initial weight： 151 g） each twice daily for 8 weeks. Results indicated that after 8 weeks of the feeding trial, red drum had the maximal level of nitric oxide（NO） content and nitric oxide synthase （NOS） activity of head kidney and brain when fed 33 263 IU/kg of dietary vitamin A; Red drum had the maximal level of NO content and NOS activity of spleen when fed 8 533 IU/kg of dietary vitamin A; Red drum had the maximal level of NO content and NOS activity of intestines when fed 18 532 IU/kg of dietary vitamin A; Red drum had the maximal level of NO content and NOS activity of thymus when fed 4 166 IU/kg of dietary vitamin A; No significant differences of NO content and NOS activity in livers were found among dietary treatments. Based on the information above, the proper dietary vitamin A could increase significantly NO content and NOS activity of red drum.