Mechanisms for Hypoxia Detection in O2-Sensitive Cells
Jpn J Physiol Vol.54, No.2 pp.109-123
Abstract: Since O2 is the bare necessity for multicellular organisms, they develop multiple protective mechanisms against hypoxia. Mammals will adapt to hypoxia in short and long terms. The short-term responses include enhancement of the respiratory and cardiac functions, adrenaline secretion from adrenal medullary cells, and pulmonary vasoconstriction, whereas the long-term response is the increase in erythropoietin production with the consequent increase in red blood cells. Although much work has been done to elucidate molecular mechanisms for O2-sensing for the last ten years, the majority of the mechanisms remain unclear. We will review mechanisms proposed for hypoxia detection in carotid body type I cells, pulmonary artery smooth muscle, adrenal medullary cells, and liver cells, with the special focus on adrenal medullary cells.
Department of Cell and System Physiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, 807-8555 Japan. minoue@med.uoeh-u.ac.jp
Copyright© 2007 by The Physiological Society of Japan