title: Liver ascorbate and glutathione disulfide levels in guinea pigs are affected by dietary ascorbate intake and the type of diet.
abstract: We studied effects on the levels and oxidant status of AA and GSH in the guinea pig liver. Group I received various doses of AA supplementation in a standard diet, Group II in a "western" high fat, high sugar, high cholesterol diet. Both diets were supplemented with 1 (Ia and IIa); 25, (Ib and IIb); and 1000, (Ic and IIc) mg AA per animal per day. The Group II animals were sacrificed during the 9th and 10th weeks, those in Group I during the 19th and 20th weeks. Liver AA levels were 30 and 26 micrograms/g in subgroups Ia and IIa, 367 and 282 micrograms/g in subgroups Ib and IIb, and 604 and 481 micrograms/g in subgroups Ic and IIc. In subgroups Ia and IIa most of the AA was detected as DHAA. DHAA and AA levels were related in a biphasic manner. GSSG content tended to increase with higher intakes of AA regardless of diet and ranged between 0.094 to 0.194 mumol/g. GSH levels were not affected by diet type or AA level. GSSG and DHAA levels were affected only by dietary AA. Changes in serum TBARS suggested a preventive effect of higher dietary ascorbate on lipid peroxidation, but only with a western type diet.
authors.affiliation: Linus Pauling Institute of Science and Medicine, Palo Alto, CA 94306, USA.
authors.forename: S
authors.initials: S
authors.lastname: Netke
authors.forename: A
authors.initials: A
authors.lastname: Niedzwiecki
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000097:blood / Q000378:metabolism*; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D003683:Dehydroascorbic Acid / Q000378:metabolism; D004032:Diet; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage; D005978:Glutathione / Q000031:analogs & derivatives* / Q000378:metabolism; D019803:Glutathione Disulfide; D006168:Guinea Pigs; D015227:Lipid Peroxidation; D008099:Liver / Q000378:metabolism*; D010084:Oxidation-Reduction; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D002791:Cholesterol, Dietary; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D017392:Thiobarbituric Acid Reactive Substances; D005978:Glutathione; D001205:Ascorbic Acid; D019803:Glutathione Disulfide; D003683:Dehydroascorbic Acid