Liver ascorbate and glutathione disulfide levels in guinea pigs are affected by dietary ascorbate intake and the type of diet.
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.
Netke
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S
Linus Pauling Institute of Science and Medicine, Palo Alto, CA 94306, USA.
Niedzwiecki
A
A
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
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