TY - JOUR
T1 - Diversity of response in vascular smooth muscle cells to change in oxygen tension
AU - Weir, E. Kenneth
AU - Reeve, Helen L.
AU - Cornfield, David N.
AU - Tristani-Firouzi, Martin
AU - Peterson, Douglas A.
AU - Archer, Stephen L.
PY - 1997
Y1 - 1997
N2 - Hypoxia causes pulmonary vasoconstriction (HPV), but also dilation of systemic vessels and the ductus arteriosus. In the adult animal, HPV is initiated by inhibition of potassium current (l(K)) in the smooth muscle cells of small resistance arteries, which results in membrane depolarization and calcium entry through voltage-gated calcium channels. The oxygen-sensitive channels that initiate HPV are 4-aminopyridine (4-AP)-sensitive delayed rectifier channels (K(DR)), the most prominent of which has a conductance of 37 pS. In the fetus, hypoxia causes pulmonary vasoconstriction through inhibition of a calcium-sensitive potassium channel (K(Ca)). In smooth muscle cells from the rabbit ductus arteriosus, which dilates in response to hypoxia, whole-cell potassium current is reversibly enhanced, rather than inhibited, by hypoxia. The principal oxygen-sensitive channel is inhibited by 4-AP and has a conductance of about 58 pS. There are morphological and electrophysiological differences between individual pulmonary artery smooth muscle cells, for example, in some cells l(K) is predominantly carried by K(DR) channels and in others by K(Ca) channels. K(DR) cells are more common in the resistance pulmonary arteries and K(Ca) in the conduit arteries. Responses of specific vessels (conduit, resistance; pulmonary, systemic, ductus) at different stages of development (fetal, neonatal and adult) to changes in oxygen tension may be determined by the distribution of a variety of ion channels in the smooth muscle cells.
AB - Hypoxia causes pulmonary vasoconstriction (HPV), but also dilation of systemic vessels and the ductus arteriosus. In the adult animal, HPV is initiated by inhibition of potassium current (l(K)) in the smooth muscle cells of small resistance arteries, which results in membrane depolarization and calcium entry through voltage-gated calcium channels. The oxygen-sensitive channels that initiate HPV are 4-aminopyridine (4-AP)-sensitive delayed rectifier channels (K(DR)), the most prominent of which has a conductance of 37 pS. In the fetus, hypoxia causes pulmonary vasoconstriction through inhibition of a calcium-sensitive potassium channel (K(Ca)). In smooth muscle cells from the rabbit ductus arteriosus, which dilates in response to hypoxia, whole-cell potassium current is reversibly enhanced, rather than inhibited, by hypoxia. The principal oxygen-sensitive channel is inhibited by 4-AP and has a conductance of about 58 pS. There are morphological and electrophysiological differences between individual pulmonary artery smooth muscle cells, for example, in some cells l(K) is predominantly carried by K(DR) channels and in others by K(Ca) channels. K(DR) cells are more common in the resistance pulmonary arteries and K(Ca) in the conduit arteries. Responses of specific vessels (conduit, resistance; pulmonary, systemic, ductus) at different stages of development (fetal, neonatal and adult) to changes in oxygen tension may be determined by the distribution of a variety of ion channels in the smooth muscle cells.
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U2 - 10.1038/ki.1997.62
DO - 10.1038/ki.1997.62
M3 - Article
C2 - 9027722
AN - SCOPUS:0031020861
SN - 0085-2538
VL - 51
SP - 462
EP - 466
JO - Kidney international
JF - Kidney international
IS - 2
ER -