title: Altered aquaporins in the brains of mice submitted to intermittent hypoxia model of sleep apnea.
abstract: Rostral fluid displacement has been proposed as a pathophysiologic mechanism of both central and obstructive sleep apnea. Aquaporins are membrane proteins that regulate water transport across the cell membrane and are involved in brain edema formation and resolution. The present study investigated the effect of intermittent hypoxia (IH), a model of sleep apnea, on brain aquaporins. Mice were exposed to intermittent hypoxia to a nadir of 7% oxygen fraction. Brain water content, Aquaporin-1 and Aquaporin-3 were measured in the cerebellum and hippocampus. Hematoxylin-eosin and immunohistochemistry stainings were performed to evaluate cell damage. Compared to the sham group, the hypoxia group presented higher brain water content, lower levels of Aquaporin-1 and similar levels of Aquaporin-3. Immunoreactivity to GFAP and S100B was stronger in the hypoxia group in areas of extensive gliosis, compatible with cytotoxic edema. These findings, although preliminary, indicate an effect of IH on aquaporins levels. Further investigation about the relevance of these data on the pathophysiology of OSA is warranted.
authors.affiliation: Laboratorio Interdisciplinar de Pesquisa em Sono, Centro de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. diego@baronio.com.br
authors.forename: Diego
authors.initials: D
authors.lastname: Baronio
authors.forename: Denis
authors.initials: D
authors.lastname: Martinez
authors.forename: Cintia Zappe
authors.initials: CZ
authors.lastname: Fiori
authors.forename: Victorio
authors.initials: V
authors.lastname: Bambini-Junior
authors.forename: Luiz Felipe
authors.initials: LF
authors.lastname: Forgiarini
authors.forename: Darlan
authors.initials: D
authors.lastname: Pase da Rosa
authors.forename: Lenise Jihe
authors.initials: LJ
authors.lastname: Kim
authors.forename: Marcelle Reesink
authors.initials: MR
authors.lastname: Cerski
mesh_terms: D000818:Animals; D020346:Aquaporins / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D004195:Disease Models, Animal; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D000860:Hypoxia / Q000150:complications; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009414:Nerve Growth Factors / Q000378:metabolism; D009929:Organ Size; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000378:metabolism; D012891:Sleep Apnea Syndromes / Q000209:etiology / Q000473:pathology*; D018709:Statistics, Nonparametric; D014867:Water / Q000378:metabolism
chemical_list: D020346:Aquaporins; D005904:Glial Fibrillary Acidic Protein; D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C579159:S100b protein, mouse; D014867:Water