title: The effects of dietary vitamin C on growth, liver vitamin C and serum cortisol in stressed and unstressed juvenile soft-shelled turtles (Pelodiscus sinensis).
abstract: We studied the effect of dietary vitamin C on growth, liver vitamin C and serum cortisol levels in stressed and unstressed juvenile soft-shelled turtles. Turtles were fed with vitamin C supplementation at dosages of 0, 250, 500, 2500, 5,000 or 10,000 mg/kg diet for 4 weeks. Vitamin C supplementation exerted significant effects on specific growth rate and liver vitamin C concentrations. The specific growth rate peaked in the group fed at 500 mg/kg diet, while liver vitamin C levels increased with increasing dietary vitamin C levels. Serum cortisol concentrations did not differ between groups of turtles fed diets supplemented with vitamin C in the range of 0-10,000 mg/kg. After acid stress, hepatic vitamin C levels were unaffected, while serum cortisol in the control group was significantly elevated (P<0.01). The other five groups of turtles did not show significant changes in serum cortisol compared with pre-stress levels.
authors.affiliation: Ministry of Education, Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Life Sciences, Beijing Normal University, Beijing 100875, PR China. xianqingzhou@yahoo.com.cn
authors.forename: Xianqing
authors.initials: X
authors.lastname: Zhou
authors.forename: Mengxia
authors.initials: M
authors.lastname: Xie
authors.forename: Cuijuan
authors.initials: C
authors.lastname: Niu
authors.forename: Ruyong
authors.initials: R
authors.lastname: Sun
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000032:analysis / Q000494:pharmacology*; D004032:Diet / Q000662:veterinary; D004305:Dose-Response Relationship, Drug; D006854:Hydrocortisone / Q000097:blood; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D013312:Stress, Physiological / Q000097:blood / Q000139:chemically induced; D014426:Turtles / Q000097:blood / Q000254:growth & development / Q000502:physiology*
chemical_list: D001205:Ascorbic Acid; D006854:Hydrocortisone