Physiological responses in vitamin C system during hibernation in juvenile Chinese soft-shelled turtle Pelodiscus sinensis

Vitamin C (Vc) is an important antioxidant that helps turtles tolerating stressful environment. This work quantified changes in tissue Vc levels during winter hibernation in the soft-shelled turtle Pelodiscus sinensis , to reveal the stress response pattern of tissue Vc during hibernation and contribute basic data for turtle culture. We sampled juvenile soft-shelled turtles at pre-hibernation (17.0°C mud temperature;MT), during hibernation (5.8°C MT) and after arousal (20.1°C MT) in the field. The transcript levels of the gene encoding L-gulonolactone oxidase (GLO), the key enzyme for Vc synthesis, decreased significantly during hibernation. However, GLO activity did not match the GLO transcription patterns and remained stable during hibernation, and showed temperature-dependent kinetic characteristics. Vitamin C levels in the brain, liver, kidney, and spleen (but not muscle) all decreased significantly during hibernation, but recovered to pre-hibernation levels or even higher levels after arousal. The soft-shelled turtle endured 5 months of hibernation with no significant oxidative damage in most tissues, except in the spleen. Splenic Vc was nearly exhausted during hibernation, accompanied by a significantly elevated malonaldehyde (MDA) level. Although the high level of oxidative damage quickly decreased after arousal, the potential tissue damage in the spleen during hibernation might account for the weakened immune capacity of turtles after hibernation.

Effects of acute cold exposure on oxidative balance and total antioxidant capacity in juvenile Chinese soft-shelled turtle,Pelodiscus sinensis

Acute cold exposure may disturb the physiological homeostasis of the body in ectotherms.To date,there has been no information on the effects of cold exposure on homeostasis of reactive oxygen species(ROS)or antioxidant defense response in the Chinese soft-shelled turtle,Pelodiscus sinensis.In this study,P.sinensis juveniles were acclimated at 28℃,transferred to 8℃ as cold exposure for 12 h,then moved back to 28℃ rewarming for 24 h.We measured the ROS level and total antioxidant capacity(TAC)in the brain,liver,kidney and spleen at 2 and 12 h cold exposure,and at the end of the rewarming period.Malonaldehyde(MDA)and carbonyl protein were used as markers of oxidative damage.Turtles being maintained simultaneously at 28℃ were used as the control group.Cold exposure did not disturb the ROS balance in all 4 tissues,while rewarming raised the ROS level in the brain and kidney of P.sinensis.Cold exposure and rewarming decreased the TAC in the brain,liver and spleen but did not change the TAC in the kidney.MDA and carbonyl protein levels did not increase during the treatment,indicating no oxidative damage in all 4 tissues of P.sinensis.Our results indicated that extreme cold exposure did not impact the inner oxidative balance of P.sinensis,but more ROS was produced during rewarming.P.sinensis showed good tolerance to the harsh temperature change through effective protection of its antioxidant defense system to oxidative damage.This study provides basic data on the stress biology of P.sinensis.

Division of Chinese soft-shelled turtle intestine with molecular markers is slightly different from the morphological and histological observation

The Chinese soft-shelled turtle(Pelodiscus sinensis)is a commercially important species in Asian countries.Knowledge of its nutritional requirements and physiology is essential for determining the appropriate content of the feed for this animal.However,the lack of functional characterization of the intestine of this turtle limits the understanding of its absorption and utilization of nutritional materials.To solve this problem,this work utilized anatomical and histological methods to characterize 9 segments sampled along the anterior-posterior axis of the intestine.Furthermore,9 genes,which have been well documented in the intestine division of mammals and fish,were employed to functionally characterize the 9 sampled segments.Our results suggest that regions covering from the starting site to S3(position at 29.9%of the total length from the starting of the intestine)are the equivalent of mammalian dedumonen,and those covering S4(40.2%)and S5(65.4%),posterior to S8(92.7%),are the equivalent of the mammalian ileum and the large intestine,respectively.As to the region spaning S6(81.3%)and S7(87.3%),its functional equivalent(small intestine or large intestine)may be variable and depends on the functional genes.This molecular characterization in relation to the division of the intestine of Chinese soft-shelled turtle may contribute to the understanding of the nutritional physiology of the turtle,and promote Chinese soft-shelled turtle production.

中华鳖粉胶原蛋白不同提取方式的比较与理化表征

为减少水产品资源流失,提高鳖类产品附加值,该文以中华鳖粉为原料,分别采用柠檬酸、胃蛋白酶、酸性蛋白酶、风味蛋白酶、木瓜蛋白酶等方法提取酸溶性胶原和酶溶性胶原,探究鳖源胶原蛋白原料的应用价值。使用氨基酸自动分析仪、扫描电子显微镜、SDS-PAGE凝胶电泳、傅里叶红外光谱仪、气相-质谱联用仪、差式量热扫描仪对胶原蛋白的氨基酸、二级结构、挥发性物质、热稳定性等理化指标进行测定。结果表明,5种胶原蛋白均具有I型胶原特征,且纯度较高,但不同方法间提取效率存在差异。其中,胃蛋白酶溶性胶原蛋白具有较高的提取率与热稳定性,具有亚氨基酸含量高、蛋白交联程度好、气味物质少等优势,在食品与医药领域具有较好的应用前景,为后续鳖源胶原的提取与应用提供了理论基础。

凉血解毒散对鳖红脖子病的临床治疗

鳖的红脖子病是由嗜水气单胞菌引起的一种急性传染病 .本试验运用中医学理论对其进行辨证施治 ,组方凉血解毒散应用于预防和临床治疗 ,获得了很好的治疗效果 .证明该方与抗菌素一样能有效地防治鳖的红脖子病 .并通过抑菌试验 。