title: Research Report: Intermittent hypobaric hypoxia and hyperbaric oxygen on GAP-43 in the rat carotid body.
abstract: Adaptive changes in the carotid body (CB) including the expression of the growth-associated protein-43 (GAP-43) have been studied in response to low, but not high, oxygen exposure. Expression of GAP-43 in the CB of rats under different atmospheric pressures and oxygen partial pressure (PO2) conditions was investigated. Mature male Sprague-Dawley rats were exposed to intermittent hypobaric hypoxia (IHH, 0, 1, 2 and 3 weeks), intermittent hyperbaric oxygen (IHBO2, 0, 1, 5 and 10 days, sacrificed six hours or 24 hours after the last HBO2 exposure), and intermittent hyperbaric normoxia (IHN, same treatment pattern as IHBO2). GAP-43 was highly expressed (mainly in type I cells) in the CB of normal rats. IHH u-regulated GAP-43 expression in the CB with significant differences (immunohistochemical staining [IHC]: F(3,15)=40.64, P < 0.01; western blot [WB]: F(3,16) = 53.52, P < 0.01) across the subgroups. GAP-43 expression in the CB was inhibited by IHBO2 (controls vs. IHBO2 groups, IHC: F(6,30) = 15.85, P < 0.01; WB: F(6,29) = 15.95, P < 0.01). No detectable changes in GAP-43 expression were found for IHN. These findings indicated that different PO2 conditions, but not air pressures, played an important role in the plasticity of the CB, and that GAP-43 might be a viable factor for the plasticity of the CB.
authors.forename: Zhengwu
authors.initials: Z
authors.lastname: Peng
authors.forename: Juan
authors.initials: J
authors.lastname: Fan
authors.forename: Ling
authors.initials: L
authors.lastname: Liu
authors.forename: Fang
authors.initials: F
authors.lastname: Kuang
authors.forename: Fen
authors.initials: F
authors.lastname: Xue
authors.forename: Bairen
authors.initials: B
authors.lastname: Wang
mesh_terms: D000818:Animals; D001274:Atmospheric Pressure; D015153:Blotting, Western; D002344:Carotid Body / Q000378:metabolism*; D019922:GAP-43 Protein / Q000378:metabolism*; D006931:Hyperbaric Oxygenation / Q000379:methods*; D000860:Hypoxia / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D010100:Oxygen; D010313:Partial Pressure; D051381:Rats; D017207:Rats, Sprague-Dawley; D058028:Research Report; D013997:Time Factors
chemical_list: D019922:GAP-43 Protein; D010100:Oxygen