title: Differential expression of pro-inflammatory cytokines, endothelin-1 and nitric oxide synthases in the rat carotid body exposed to intermittent hypoxia.
abstract: The enhanced carotid body (CB) chemosensory response to hypoxia induced by chronic intermittent hypoxia (CIH) has been attributed to oxidative stress, which is expected to increase the expression of chemosensory modulators including chemoexcitatory pro-inflammatory cytokines in the CB. Accordingly, we studied the time-course of the changes in the immunohistological expression of TNF-α, IL-1β, IL-6, ET-1, iNOS, eNOS and 3-nitrotyrosine in the CB, along with the progression of enhanced CB chemosensory responses to acute hypoxia in male Sprague-Dawley rats exposed to CIH (5%O₂, 12 times/h per 8h) for 7, 14 and 21 days. Exposure to CIH for 7 days resulted in a sustained potentiation of CB chemosensory responses to acute hypoxia, which persisted until 21 days of CIH. The chemosensory potentiation was paralleled by an increased 3-nitrotyrosine expression in the CB. On the contrary, CIH produced a transient 2-fold increase of ET-1 immunoreactivity at 7 days, a decrease in eNOS immunoreactivity, and a delayed but progressive increase of TNF-α, IL-1β and iNOS immunoreactivity, which was not associated with changes in systemic plasma levels or immune cell invasion within the CB. Thus, present results suggest that the local expression of chemosensory modulators and pro-inflammatory cytokines in the CB may have different temporal contribution to the CB chemosensory potentiation induced by CIH.
authors.affiliation: Laboratorio de Neurobiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, Santiago, Chile.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Del Rio
authors.forename: Esteban A
authors.initials: EA
authors.lastname: Moya
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Iturriaga
mesh_terms: D000818:Animals; D002344:Carotid Body / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D016207:Cytokines / Q000096:biosynthesis* / Q000097:blood; D004195:Disease Models, Animal; D019332:Endothelin-1 / Q000096:biosynthesis* / Q000097:blood; D002534:Hypoxia, Brain / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology*; D007249:Inflammation / Q000097:blood / Q000201:enzymology / Q000378:metabolism; D018836:Inflammation Mediators / Q000097:blood / Q000378:metabolism*; D008297:Male; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis*; D052250:Nitric Oxide Synthase Type III / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D015854:Up-Regulation / Q000502:physiology
chemical_list: D016207:Cytokines; D019332:Endothelin-1; D018836:Inflammation Mediators; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III