title: Role of Kir2.2 in hypercapnic ventilatory response during postnatal development of mouse.
abstract: In order to determine the role of Kir2.2 in the hypercapnic ventilatory response (HCVR) during postnatal development, we measured the response of the Kir2.2-knockout (Kir2.2-/-) mouse in an unanesthetized unrestrained state by means of pressure plethysmography on postnatal days 9-10, 14-15 and 18, and compared the response with that in its wild counterpart, the FVB mouse. We also examined developmental changes in m-RNA expression of Kir2.2 in the brainstem of the FVB mouse using quantitative real-time PCR assay. Kir2.2-/- exhibited a smaller increase in tidal volume and minute ventilation volume than the FVB mouse in response to hypercapnic challenge on days 14-15. Meanwhile, the FVB mouse showed a transient increase in m-RNA expression of Kir2.2 in the brainstem on days 14-15. These findings suggest that Kir2.2 in the brainstem plays a transient role in HCVR, possibly through central ventilatory chemosensitivity, during postnatal development.
authors.affiliation: Cardiopulmonary Division, Department of Internal Medicine, School of Medicine, Keio University, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582, Japan. oyamaday@cpnet.med.keio.ac.jp
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Oyamada
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Michie
authors.initials: M
authors.lastname: Murai
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Hakuno
authors.forename: Akitoshi
authors.initials: A
authors.lastname: Ishizaka
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development*; D015139:Blotting, Southern / Q000379:methods; D001933:Brain Stem / Q000254:growth & development / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D005838:Genotype; D006935:Hypercapnia / Q000235:genetics / Q000503:physiopathology*; D051379:Mice; D018345:Mice, Knockout; D010641:Phenotype; D010991:Plethysmography / Q000379:methods; D024661:Potassium Channels, Inwardly Rectifying / Q000172:deficiency / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D012119:Respiration; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013990:Tidal Volume / Q000235:genetics; D014851:Wakefulness / Q000502:physiology
chemical_list: C489463:Kir2.2 channel; D024661:Potassium Channels, Inwardly Rectifying; D012333:RNA, Messenger