The role of NADPH oxidase in carotid body arterial chemoreceptors.

نویسندگان

  • B Dinger
  • L He
  • J Chen
  • X Liu
  • C Gonzalez
  • A Obeso
  • K Sanders
  • J Hoidal
  • L Stensaas
  • S Fidone
چکیده

O(2)-sensing in the carotid body occurs in neuroectoderm-derived type I glomus cells where hypoxia elicits a complex chemotransduction cascade involving membrane depolarization, Ca(2+) entry and the release of excitatory neurotransmitters. Efforts to understand the exquisite O(2)-sensitivity of these cells currently focus on the coupling between local P(O2) and the open-closed state of K(+)-channels. Amongst multiple competing hypotheses is the notion that K(+)-channel activity is mediated by a phagocytic-like multisubunit enzyme, NADPH oxidase, which produces reactive oxygen species (ROS) in proportion to the prevailing P(O2). In O(2)-sensitive cells of lung neuroepithelial bodies (NEB), multiple studies confirm that ROS levels decrease in hypoxia, and that E(M) and K(+)-channel activity are indeed controlled by ROS produced by NADPH oxidase. However, recent studies in our laboratories suggest that ROS generated by a non-phagocyte isoform of the oxidase are important contributors to chemotransduction, but that their role in type I cells differs fundamentally from the mechanism utilized by NEB chemoreceptors. Data indicate that in response to hypoxia, NADPH oxidase activity is increased in type I cells, and further, that increased ROS levels generated in response to low-O(2) facilitate cell repolarization via specific subsets of K(+)-channels.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Spironolactone Inhibits NADPH Oxidase-Mediated Oxidative Stress and Dysregulation of the Endothelial NO Synthase in Human Endothelial Cells

Accumulating evidence indicates that aldosterone plays a critical role in the mediation of oxidative stress and vascular damage. NADPH oxidase has been recognized as a major source of oxidative stress in vasculature. However, the relation between NADPH oxidase in aldosterone-mediated oxidative stress in endothelial cells remains to be ascertained. The present study aimed to investigate the rel...

متن کامل

Spironolactone Inhibits NADPH Oxidase-Mediated Oxidative Stress and Dysregulation of the Endothelial NO Synthase in Human Endothelial Cells

Accumulating evidence indicates that aldosterone plays a critical role in the mediation of oxidative stress and vascular damage. NADPH oxidase has been recognized as a major source of oxidative stress in vasculature. However, the relation between NADPH oxidase in aldosterone-mediated oxidative stress in endothelial cells remains to be ascertained. The present study aimed to investigate the rel...

متن کامل

Modulation of chronic hypoxia-induced chemoreceptor hypersensitivity by NADPH oxidase subunits in rat carotid body.

Previous studies in our laboratory established that reactive oxygen species (ROS) generated by NADPH oxidase (NOX) facilitate the open state of a subset of K+ channels in oxygen-sensitive type I cells of the carotid body. Thus pharmacological inhibition of NOX or deletion of a NOX gene resulted in enhanced chemoreceptor sensitivity to hypoxia. The present study tests the hypothesis that chronic...

متن کامل

The role of the carotid body in mediating the cerebrovascular response to altered arterial carbon dioxide tension.

The role of the carotid bifurcation chemoreceptors in mediating the cerebrovascular response to altered arterial PCO2 has been suggested to be large. In the present study the cerebrovascular response to raised PCO2 was measured in a group of baboons before and after bilateral inactivation of the carotid bodies. The results suggest that these chemoreceptors do play a part in the cerebral vasodil...

متن کامل

Cardiovascular adjustments induced by hypertonic saline in hemorrhagic rats: Involvement of carotid body chemoreceptors

The peripheral hyperosmolarity elicited by intravenous infusion of hypertonic saline brings potential benefits to the treatment of hemorrhage. The neural mechanisms involved in these beneficial effects remain unknown. The present study examines the role of carotid chemoreceptors in cardiovascular responses induced by hypertonic saline after hypovolemic hemorrhage in rats. Male Wistar rats (300-...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Respiratory physiology & neurobiology

دوره 157 1  شماره 

صفحات  -

تاریخ انتشار 2007