Neuroprotective effect of vitamin C against the ethanol and nicotine modulation of GABA(B) receptor and PKA-alpha expression in prenatal rat brain.
Prenatal ethanol exposure has various deleterious effects on neuronal development and can induce various defects in developing brain, resulting in fetal alcohol syndrome (FAS). gamma-Aminobutyric acid (GABA(B)) receptor (R) is known to play an important role during the development of the central nervous system (CNS). Our study was designed to investigate the effect of ethanol (100 mM), nicotine (50 microM) (for 30 min and 1 h), vitamin C (vitC, 0.5 mM), ethanol plus vitC, and nicotine plus vitC on expression level of GABA(B1), GABA(B2)R, and protein kinase A-alpha (PKA) in prenatal rat cortical and hippocampal neurons at gestational days (GD) 17.5. The results showed that, upon ethanol and nicotine exposure, GABA(B1) and GABA(B2)R protein expression increased significantly in the cortex and hippocampus for a short (30 min) and long term (1 h), whereas only GABA(B2)R subunit was decreased upon nicotine exposure for a long term in the cortex. Furthermore, PKA expression in cortex and hippocampus increased with ethanol exposure during short term, whereas long-term exposure results increased in cortex and decreased in hippocampus. Moreover, the cotreatment of vitC with ethanol and nicotine showed significantly decreased expression of GABA(B1), GABA(B2)R, and PKA in cortex and hippocampus for a long-term exposure. Mitochondrial membrane potential, Fluoro-jade-B, and propidium iodide staining were used to elucidate possible neurodegeneration. Our results suggest the involvement of GABA(B)R and PKA in nicotine and ethanol-mediated neurodevelopmental defects and the potential use of vitC as a effective protective agent for FAS-related deficits.
Naseer
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Division of Life Science, College of Natural Sciences and Applied Life Science (Brain Korea 21), Gyeongsang National University, Chinju 660-701, South Korea.
Lee
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Kim
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D020268:Alcohol-Induced Disorders, Nervous System / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology / Q000627:therapeutic use; D001205:Ascorbic Acid / Q000494:pharmacology* / Q000627:therapeutic use; D002478:Cells, Cultured; D002492:Central Nervous System Depressants / Q000037:antagonists & inhibitors / Q000633:toxicity; D017868:Cyclic AMP-Dependent Protein Kinases / Q000187:drug effects / Q000378:metabolism; D000431:Ethanol / Q000037:antagonists & inhibitors* / Q000633:toxicity; D005260:Female; D018696:Neuroprotective Agents / Q000494:pharmacology* / Q000627:therapeutic use; D009538:Nicotine / Q000037:antagonists & inhibitors / Q000633:toxicity; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced / Q000188:drug therapy* / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018080:Receptors, GABA-B / Q000187:drug effects / Q000378:metabolism
D000975:Antioxidants; D002492:Central Nervous System Depressants; D018696:Neuroprotective Agents; D018080:Receptors, GABA-B; D000431:Ethanol; D009538:Nicotine; D017868:Cyclic AMP-Dependent Protein Kinases; D001205:Ascorbic Acid