It is assumed that those species that are not scurvy prone do have an absorption mechanism by diffusion (Spencer et al., 1963).
It is assumed that those species that are not scurvy prone do have an absorption mechanism by diffusion (Spencer et al., 1963).Tags: Academic Literature Review ExampleDyslexia Research PapersHow To Write Conclusion For EssayDissertation Writing FellowshipEssay On RajguruAp Government Essay QuestionsEssay Mla StyleHannah Montana Essay WinnerAerospace Engineer Research Paper
Since this change takes place readily, vitamin C is very susceptible to destruction through oxidation, which is accelerated by heat and light.
Reversible oxidation-reduction of ascorbic acid with dehydroascorbic acid is the most important chemical property of vitamin C and the basis for its known physiological activities and stabilities (Moser and Bendich, 1991).
In experimental animals, highest concentrations of vitamin C are found in the pituitary and adrenal glands, and high levels are also found in the liver, spleen, brain and pancreas.
Vitamin C also tends to localize around healing wounds.
Under normal conditions, dogs and cats can synthesize vitamin C within their body.
Because of de novo synthesis, vitamin C is not technically a dietary required vitamin for healthy dogs and cats.Vitamin C occurs in two forms, namely L-ascorbic acid (reduced form) and dehydro-L-ascorbic acid (oxidized form).Although in nature the vitamin is primarily present as ascorbic acid, both forms are biologically active.Function of vitamin C is related to its reversible oxidation and reduction characteristics; however, the exact role of this vitamin in the living system is not completely understood, since a coenzyme form has not yet been reported.In addition to the relationship of ascorbic acid to hydroxylase enzymes, Franceschi (1992) suggests that vitamin C is required for differentiation of connective tissue such as muscle, cartilage and bone derived from mesenchyme (embryonic cells capable of developing into connective tissue).No specific binding proteins for ascorbic acid have been reported, and it is suggested that the vitamin is retained by binding to subcellular structures.Ascorbic acid is widely distributed throughout the tissues, both in animals capable of synthesizing vitamin C as well as in those dependent on an adequate dietary amount of the vitamin.Bioavailability of vitamin C in feeds is limited, but apparently 80% to 90% appears to be absorbed (Kallner et al., 1977).Site of absorption in the guinea pig is in the duodenal and proximal small intestine, whereas the rat showed highest absorption in the ileum (Hornig et al., 1984).The most clearly established functional role for vitamin C involves collagen biosynthesis.Beneficial effects result from ascorbic acid in the synthesis of “repair” collagen.