الفهرس 
ChemicaI structure of ascorbic acidOnly 14 pages are availabe for public view
 |  | from | 104 |  |  |
| | | from | 104 | | |
Abstract
Ascorbic acid is essential for normal metabol ism in animal cells. Some species do not have the ability to synthesize ascorbic acid in vivo due to the lack of L-gluconolactone oxidase which catalyse the terminal step in the conversion of glucose to ascorbic acid. Vit. C is required for Collagen synthesis, degradätion of tyrbsine, bile acid formation absorption of iron. Most fish including tilapia require an exogenous dietary source of the vitamine for normal development and growth. Several workers have demonstrated the deficiency signs of vit. C in many fish species (Hatv*r, et al., 1969; I,ovcll, 1973; Hilton et al., 1978; Mahajan et al., 1980; SoHman et al., 1986; Al-Antoudi et aI., 1992; Shian and Hsu, 1995; Atexfe et al., 1997 and Phromkunthong et al., 1997). The level of vit. C that reaiize the highest growth was investigated, but the results were different due to the form of vit.C, used species of fish and the environmental condition. Lilüd Lovell, 1985 have also, suggested that mega dose of feeding of dietary aateö*bic acid
enhanced the humoral immune responses, antibody prfedüction and
* complement activity in channel catfish.