Age-dependent involvement of ATP-sensitive potassium channel Kir6.2 in hypoxic ventilatory depression of mouse.
In order to examine whether ATP-sensitive potassium channel Kir6.2 is involved in hypoxic ventilatory responses, especially in hypoxic ventilatory depression (HVD), and whether the involvement shows age-dependence, we measured the hypoxic ventilatory response in the Kir6.2-knockout mouse (Kir6.2-/-) in an unanesthetized unrestrained state by means of pressure plethysmography in the 2nd and 4th postnatal weeks, and compared the response with that of its wild type counterpart, the C57BL6/J mouse. In the 4th postnatal week, but not in the 2nd week, the Kir6.2-/- exhibited a larger and longer initial augmentation and a weaker subsequent depression of respiratory frequency and ventilation in response to hypoxia (FIO(2)=0.12 in N(2)). These findings suggest that Kir6.2 is involved in HVD of the mouse at a certain point during the postnatal development.
Oyamada
Yoshitaka
Y
Department of Pulmonary Medicine, School of Medicine, Keio University, 35 Shinano-machi, Shinjuku-ku, Tokyo, Japan. oyamaday@cpnet.med.keio.ac.jp
Murai
Michie
M
Harada
Naoko
N
Ishizaka
Akitoshi
A
Okada
Yasumasa
Y
D000255:Adenosine Triphosphate / Q000494:pharmacology / Q000502:physiology*; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001835:Body Weight / Q000235:genetics; D000860:Hypoxia; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010100:Oxygen / Q000378:metabolism; D024661:Potassium Channels, Inwardly Rectifying / Q000172:deficiency / Q000502:physiology*; D012123:Pulmonary Ventilation / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors; D000099161:Kcnj11 Channel
D000255:Adenosine Triphosphate; D010100:Oxygen; D024661:Potassium Channels, Inwardly Rectifying; D000099161:Kcnj11 Channel