title: Insulin signaling in chick embryos exposed to alcohol.
abstract: Although insulin is known to be an important generator of regulatory signals during fetal growth and development, neither the immediate nor long-term effects of alcohol (ethanol) on insulin action are well understood. In the rat, fetal exposure to alcohol has been shown to be correlated with a subsequent abnormal response to a glucose load in the neonate and adult. Further, fetal hypoplasia secondary to maternal alcohol consumption is correlated with decreased placental glucose transport and with a lowering of the glucose levels in fetal tissues. However, the fetal effects of alcohol cannot be completely overcome by glucose/caloric supplementation, suggesting that factors other than glucose transport are involved. Using an embryonic chick model that negates the factors of maternal/placental metabolism and transport, the current study found that fetal alcohol exposure markedly increased insulin binding in developing tissue, but had little effect on the binding of the insulin-like growth factors. Competitive binding experiments revealed a marked increase in insulin receptor numbers, but no change in binding affinity as a result of the alcohol exposure. Basal uptake of 2-deoxyglucose by fetal tissue was lowered by alcohol exposure, but incubation with exogenous porcine insulin (1 x 10(-7) M) resulted in a significant increase in glucose uptake by the alcohol-exposed embryos. The increases in insulin binding and in insulin-dependent glucose uptake notwithstanding, exogenous insulin could not induce normal levels of ornithine decarboxylase activity in embryonic cells previously exposed to alcohol.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Biochemistry, East Carolina University, School of Medicine, Greenville, North Carolina 27858, USA.
authors.forename: S N
authors.initials: SN
authors.lastname: Pennington
authors.forename: I A
authors.initials: IA
authors.lastname: Shibley
authors.forename: K
authors.initials: K
authors.lastname: Koochek
authors.forename: M D
authors.initials: MD
authors.lastname: Gavigan
authors.forename: J M
authors.initials: JM
authors.lastname: Monaghan
authors.forename: L P
authors.initials: LP
authors.lastname: Sandstrom
authors.forename: J L
authors.initials: JL
authors.lastname: Morgan
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002642:Chick Embryo; D063647:Fetal Alcohol Spectrum Disorders / Q000503:physiopathology*; D007328:Insulin / Q000502:physiology*; D009955:Ornithine Decarboxylase / Q000502:physiology; D019000:Phosphotyrosine / Q000378:metabolism; D011972:Receptor, Insulin / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D013002:Somatomedins / Q000502:physiology
chemical_list: D001786:Blood Glucose; D007328:Insulin; D013002:Somatomedins; D019000:Phosphotyrosine; D011972:Receptor, Insulin; D009955:Ornithine Decarboxylase