Preservation of endothelium-dependent vasodilation in the spastic segment of the human epicardial coronary artery by substance P.
The objective of this study was to determine if endothelium-dependent vasodilation is preserved in the spastic segment of the epicardial coronary artery. Segmental responses of the coronary artery to substance P were examined by the use of a quantitative angiographic technique in 21 patients with variant angina. Coronary diameter at the basal state did not differ between the spastic and the nonspastic segments (2.3 +/- 0.2 mm, 2.3 +/- 0.4 mm, p greater than 0.05). Changes in coronary diameter in response to substance P did not differ between segments with ergonovine-induced spasm and nonspastic segments. Maximal dilation averaged 27.1 +/- 9.5% in the spastic segment and 24.4 +/- 9.6% in the nonspastic segment (expressed as a percent increase over the value before drug administration). It appears that both the potential of the endothelium to release endothelium-dependent relaxing factor and the dilating response of the smooth muscle to endothelium-dependent relaxing factor are preserved, even in the spastic segment.
Department of Medicine, Kyushu Welfare Pension Hospital, Fukuoka, Japan.
H
H
Yamamoto
H
H
Yoshimura
M
M
Noma
H
H
Kai
S
S
Suzuki
T
T
Tajimi
M
M
Sugihara
Y
Y
Kikuchi
D000788:Angina Pectoris, Variant / Q000000981:diagnostic imaging / Q000503:physiopathology; D017023:Coronary Angiography; D003329:Coronary Vasospasm / Q000503:physiopathology*; D003331:Coronary Vessels / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000502:physiology*; D004874:Ergonovine; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000502:physiology*; D013373:Substance P / Q000494:pharmacology*; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*
D009569:Nitric Oxide; D013373:Substance P; D004874:Ergonovine