title: Effects of aging and antioxidants on glucose transport in rat adipocytes.
abstract: The free radical theory of aging postulates that free radicals are the underlying cause of aging. One of the well-established age-associated disorders is the decrease in the insulin-stimulated glucose transport through the cell membrane which was reported to be a major mechanism underlying insulin resistance in old rats. The present study investigates the protective capacity of two known antioxidants, vitamin C and butylated hydroxytoluene (BHT), against age-associated free radical damage, which could be the reason behind the decreased insulin-stimulated glucose transport in old animals. Maximum insulin-stimulated glucose transport has been estimated in adipocytes isolated from adult 6-month-old Fischer rats and from senile 24-month-old control rats as well as from 24-month-old rats that were fed either vitamin C or BHT for 18 months. A significant increase in maximum insulin-stimulated glucose transport was observed in the BHT (p = 0.015) and the vitamin C groups (p = 0.039) compared with the control group of the same age. Significant stimulations with insulin over basal activities were also observed in the BHT group (p = 0.0001) as well as the vitamin C group (p = 0.009), while a nonsignificant stimulation (p = 0.097) was observed in the old control group. This study suggests a protective role that BHT (fat soluble) may have on the lipid moiety of the cell membrane and vitamin C (water soluble) on one or more of the intracellular cytoplasmic constituents concerned with glucose transport.
authors.affiliation: Department of Zoology, Faculty of Science, Suez Canal University, Ismailia, Egypt.
authors.forename: S A
authors.initials: SA
authors.lastname: Moustafa
authors.forename: J E
authors.initials: JE
authors.lastname: Webster
authors.forename: F E
authors.initials: FE
authors.lastname: Mattar
mesh_terms: D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism*; D000375:Aging / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology*; D002084:Butylated Hydroxytoluene / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test; D017136:Ion Transport / Q000187:drug effects; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D000975:Antioxidants; D002084:Butylated Hydroxytoluene; D005947:Glucose; D001205:Ascorbic Acid