Autoradiographic localization of [125I]endothelin binding sites in human blood vessels and coronary tissue: functional correlates.
The distribution of endothelin-1 (ET-1) receptors on human vascular tissue has been studied. High- and low-resolution autoradiography was used to determine the distribution of [125]ET binding sites in human blood vessels and ventricular myocardium. Dense, displaceable [125I]ET binding was associated with cardiac myocytes and the smooth muscle layer of all vessels were examined. There was also dense binding to vasa vasora. There was increased [125I]ET binding to atheromatous coronary arteries and vein graft, which was associated with the tunica media and vasa vasora or regions of neovascularization. Vasoconstrictor and positive inotropic activity of ET-1 has been established in vitro. The vasoconstrictor effect of ET-1 is likely to be mediated via the binding sites identified on vascular smooth muscle. The striking perivascular [125I]ET-1 binding suggests that ET-1 may also have constrictor activity on vasa vasora. There is experimental evidence that ET-1 has mitogenic activity on vascular smooth muscle cells in culture. The increased binding to both smooth muscle and regions of neovascularization in atheromatous vessels suggests that ET-1 may play a role in atherosclerosis.
Dashwood
M R
MR
NHLI, Harefield Hospital, Middlesex, U.K.
Sykes
R M
RM
Muddle
J R
JR
Collins
M J
MJ
Prehar
S
S
Theodoropoulos
S
S
Yacoub
M H
MH
D000293:Adolescent; D000328:Adult; D000368:Aged; D001161:Arteriosclerosis / Q000378:metabolism; D001345:Autoradiography; D001665:Binding Sites; D001808:Blood Vessels / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D003331:Coronary Vessels / Q000378:metabolism*; D016232:Endothelins / Q000378:metabolism*; D005260:Female; D006801:Humans; D007223:Infant; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D017466:Receptors, Endothelin
D016232:Endothelins; D007457:Iodine Radioisotopes; D011956:Receptors, Cell Surface; D017466:Receptors, Endothelin