Different amounts of vitamin C were added to diets fed to juveniles （2.5＋0.15 g） of sea cucumber Apostichopus japonicus （Selenka） in an attempt to reduce the stress response of specimens exposed to nitrite stress...Different amounts of vitamin C were added to diets fed to juveniles （2.5＋0.15 g） of sea cucumber Apostichopus japonicus （Selenka） in an attempt to reduce the stress response of specimens exposed to nitrite stress. A commercial feed was used as the control diet and three experimental diets were made by supplementing 1 000, 1 500, or 2 000 mg vitamin C/kg diet to control diet separately in a 45-day experiment. Sea cucumbers were exposed to three different levels （0.5, 1.0, and 1.5 mg/L） of nitrite stress for 4, 8, and 12 h at four time intervals （0, 15, 30, and 45 d）. Growth of the animals was recorded during the experiment. Reactive oxygen species （ROS） （i.e. hydroxyl free radical （-OH）, malondialdehyde （MDA） and total antioxidant capacity （T-AOC）） and antioxidant enzyme activities （i.e., superoxide dismutase （SOD） and eatalase （CAT）） were measured. Response surface methodology （RSM） was used to analyze the effect of multiple factors on ROS indices and enzyme activities. Weight gain （WG） and special growth rate （SGR） of vitamin C supplementation groups were significantly higher than those of control group （P〈0.05）. The levels of-OH and MDA increased under exposure time extending and nitrite concentration increasing, whereas T-AOC level decreased. SOD and CAT activities increased at 4 h and 8 h and decreased at 12 h. During the days in which the animal consumed experimental diets, the levels of-OH and MDA decreased and that of T-AOC increased. This result suggests that diets containing vitamin C could reduce the nitrite stress response in the animals and increase their antioxidant capacity. The multifactor regression equation of growth performance, ROS indices, and duration of feeding results suggest that vitamin C supplementation of 1 400-2 000 mg/kg diet for 29-35 days could reduce effectively the effects of nitrite exposure.展开更多
越来越多的证据表明,限盐会导致胰岛素抵抗增加。该研究在盐敏感性及盐抵抗性高血压患者中比较低盐膳食对胰岛素抵抗的作用,并在一个多因素回归模型中评估血压盐敏感性与胰岛素抵抗盐敏感性的关系。入选对象经过1周高盐膳食（钠200mmol/...越来越多的证据表明,限盐会导致胰岛素抵抗增加。该研究在盐敏感性及盐抵抗性高血压患者中比较低盐膳食对胰岛素抵抗的作用,并在一个多因素回归模型中评估血压盐敏感性与胰岛素抵抗盐敏感性的关系。入选对象经过1周高盐膳食（钠200mmol/d）和1周低盐膳食（钠10mmol/d）后进行研究。盐敏感性定义为低盐膳食时收缩压下降〉15 mm Hg（1mm Hg=0.133kPa）。展开更多
基金Supported by the Main Direction Program of Knowledge Innovation of Chinese Academy of Sciences(No.KZCX2-EWQ215)
文摘Different amounts of vitamin C were added to diets fed to juveniles （2.5＋0.15 g） of sea cucumber Apostichopus japonicus （Selenka） in an attempt to reduce the stress response of specimens exposed to nitrite stress. A commercial feed was used as the control diet and three experimental diets were made by supplementing 1 000, 1 500, or 2 000 mg vitamin C/kg diet to control diet separately in a 45-day experiment. Sea cucumbers were exposed to three different levels （0.5, 1.0, and 1.5 mg/L） of nitrite stress for 4, 8, and 12 h at four time intervals （0, 15, 30, and 45 d）. Growth of the animals was recorded during the experiment. Reactive oxygen species （ROS） （i.e. hydroxyl free radical （-OH）, malondialdehyde （MDA） and total antioxidant capacity （T-AOC）） and antioxidant enzyme activities （i.e., superoxide dismutase （SOD） and eatalase （CAT）） were measured. Response surface methodology （RSM） was used to analyze the effect of multiple factors on ROS indices and enzyme activities. Weight gain （WG） and special growth rate （SGR） of vitamin C supplementation groups were significantly higher than those of control group （P〈0.05）. The levels of-OH and MDA increased under exposure time extending and nitrite concentration increasing, whereas T-AOC level decreased. SOD and CAT activities increased at 4 h and 8 h and decreased at 12 h. During the days in which the animal consumed experimental diets, the levels of-OH and MDA decreased and that of T-AOC increased. This result suggests that diets containing vitamin C could reduce the nitrite stress response in the animals and increase their antioxidant capacity. The multifactor regression equation of growth performance, ROS indices, and duration of feeding results suggest that vitamin C supplementation of 1 400-2 000 mg/kg diet for 29-35 days could reduce effectively the effects of nitrite exposure.
文摘越来越多的证据表明,限盐会导致胰岛素抵抗增加。该研究在盐敏感性及盐抵抗性高血压患者中比较低盐膳食对胰岛素抵抗的作用,并在一个多因素回归模型中评估血压盐敏感性与胰岛素抵抗盐敏感性的关系。入选对象经过1周高盐膳食（钠200mmol/d）和1周低盐膳食（钠10mmol/d）后进行研究。盐敏感性定义为低盐膳食时收缩压下降〉15 mm Hg（1mm Hg=0.133kPa）。
