title: Vitamin C prevents hyperbaric oxygen-induced growth retardation and lipid peroxidation and attenuates the oxidation-induced up-regulation of glutathione in guinea pigs.
abstract: Hyperbaric oxygen therapy is used to treat various clinical conditions, but it also causes oxidative damage. The objectives of this study are to determine if increased vitamin C intake can prevent hyperbaric oxygen-induced damage and to determine interactions among vitamin C, glutathione and vitamin E in response to oxidative stress. The growth rates of unexposed guinea pigs fed 1.25 mg vitamin C/day were indistinguishable from that of guinea pigs fed 50 mg vitamin C/day. In contrast, hyperbaric oxygen exposure resulted in growth retardation in guinea pigs fed 1.25 mg vitamin C/day, but it had little effect on the growth rates of guinea pigs fed 50 mg vitamin C/day. Increased vitamin C intake also prevented hyperbaric oxygen-induced lipid peroxidation in the liver. In guinea pigs not exposed to hyperbaric oxygen, levels of vitamin C in tissues were closely related to vitamin C intake, but tissue levels of glutathione and vitamin E were not related to vitamin C intake. However, interactions between vitamin C and glutathione were observed upon chronic hyperbaric oxygen exposure. Chronic hyperbaric oxygen exposure resulted in >2-fold increases in the levels of glutathione in liver and lung of guinea pigs fed 1.25 mg vitamin C/day. In comparison, the oxidation-induced increases in glutathione were significantly attenuated in guinea pigs fed 50 mg vitamin C/day. These data show that increased intake of vitamin C can prevent or alleviate the hyperbaric oxygen-induced damage. The interactions between vitamin C and glutathione upon hyperbaric oxygen exposure indicate that there is a homeostatic regulation of antioxidant capacity in guinea pig tissues.
authors.affiliation: Jean Mayer USDA Human Nutrition Research, Center on Aging, Tufts University, 02111, Boston, MA, USA
authors.forename: Fu
authors.initials: F
authors.lastname: Shang
authors.forename: Xin
authors.initials: X
authors.lastname: Gong
authors.forename: Shahryar
authors.initials: S
authors.lastname: Egtesadi
authors.forename: Mohsen
authors.initials: M
authors.lastname: Meydani
authors.forename: Donald
authors.initials: D
authors.lastname: Smith
authors.forename: Gayle
authors.initials: G
authors.lastname: Perrone
authors.forename: Linda
authors.initials: L
authors.lastname: Scott
authors.forename: Jeffrey B.
authors.initials: JB
authors.lastname: Blumberg
authors.forename: Allen
authors.initials: A
authors.lastname: Taylor