Systemic hypertension augments, whereas insulin-dependent diabetes down-regulates, endothelin A receptor expression in the mammary artery in coronary artery disease patients.
BACKGROUND
Endothelin (ET) A receptor antagonism causes decreased vasodilation in hypertensive coronary arteries and decreased effects on coronary artery compliance in diabetic patients.


METHODS
We investigate the mRNA expression of ET-1, ET(A) and ET(B) receptors, using real time RT-PCR, in biopsies from the internal mammary artery obtained from 49 patients, 18 diabetics and 34 hypertensives, all undergoing coronary artery bypass grafting.


RESULTS
Hypertensive patients had higher ET-1 mRNA expression (16438 [8417, 23917]), than normotensive patients (2974 [2283, 18055], p=0.008). Diabetic patients had significantly lower ET(A) receptor levels than non-diabetic patients (455 [167, 1496] vs. 1660 [700, 3190], respectively, p = 0.003).


CONCLUSIONS
Multivariate analysis demonstrated that the presence of systemic hypertension was the only independent predictor of log ET(A) receptor expression and log ET-1 expression, while insulin-dependent diabetes was negatively correlated with ET(A) receptor expression. ETB receptor expression was not correlated with any predictor. Systemic hypertension is associated with increased ET-1 and ET(A) receptor mRNA expression, whereas insulin-dependent diabetes down-regulates ET(A) receptor mRNA expression in the internal mammary artery in patients with coronary artery disease undergoing bypass grafting.
Zygalaki
Eleni
E
Laboratory of Analytical Chemistry, Department of Chemistry, University of Athens, Greece.
Kaklamanis
Loukas
L
Lolaka
Maria
M
Nikolaou
Nikolaos
N
Koutouzis
Michael
M
Lianidou
Evi S
ES
Kyriakides
Zenon S
ZS
D000368:Aged; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000503:physiopathology* / Q000601:surgery; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D015536:Down-Regulation / Q000502:physiology; D019332:Endothelin-1 / Q000235:genetics; D005260:Female; D015870:Gene Expression / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008323:Mammary Arteries / Q000502:physiology* / Q000601:surgery; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D012333:RNA, Messenger / Q000378:metabolism; D044022:Receptor, Endothelin A / Q000235:genetics*; D044023:Receptor, Endothelin B / Q000235:genetics; D014664:Vasodilation / Q000502:physiology
D019332:Endothelin-1; D012333:RNA, Messenger; D044022:Receptor, Endothelin A; D044023:Receptor, Endothelin B