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Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học General Psychiatry cung cấp cho các bạn kiến thức về ngành y đề tài: Physiology in medicine: importance of hypoxic pulmonary vasoconstriction in maintaining arterial oxygenation during acute respiratory failure. | Available online http ccforum.eom content 5 2 067 Review Physiology in medicine importance of hypoxic pulmonary vasoconstriction in maintaining arterial oxygenation during acute respiratory failure Robert Naeije and Serge Brimioulle Department of Physiology Erasme Campus of the Free University of Brussels Belgium Department of Intensive Care Erasme Hospital Free University of Brussels Belgium Correspondence R Naeije MD PhD Department of Physiology CP 604 Erasme Campus CP 604 808 Lennik Road B-1070 Brussels Belgium. Tel 32 2 5553322 fax 32 2 5554124 e-mail rnaeije@ulb.ac.be Received 18 February 2001 Accepted 19 February 2001 Published 6 March 2001 Critical Care 2001 5 67-71 2001 BioMed Central Ltd Print ISSN 1364-8535 Online ISSN 1466-609X Abstract Hypoxic pulmonary vasoconstriction continues to attract interest more than half a century after its original report because of persistent mystery about its biochemical mechanism and its exact physiological function. Recent work suggests an important role for pulmonary arteriolar smooth muscle cell oxygen-sensitive voltage-dependent potassium channels. Inhibition of these channels by decreased PO2 inhibits outward potassium current causing membrane depolarization and calcium entry through voltage-dependent calcium channels. Endothelium-derived vasoconstricting and vasodilating mediators modulate this intrinsic smooth muscle cell reactivity to hypoxia. However refined modeling of hypoxic pulmonary vasoconstriction operating as a feedback mechanism in inhomogeneous lungs using more realistic stimulus-response curves and confronted with direct measurements of regional blood flow distribution shows a more effective than previously assessed ability of this remarkable intrapulmonary reflex to improve gas exchange and arterial oxygenation. Further studies could show clinical benefit of pharmacological manipulation of hypoxic pulmonary vasoconstriction in circumstances of life-threatening hypoxemia. Keywords acute respiratory .
