Endothelial dysfunction in small resistance arteries of patients with non-insulin-dependent diabetes mellitus.
OBJECTIVE
Arterial hypertension is frequently associated with the presence of endothelial dysfunction in human subcutaneous small resistance arteries, as evaluated by responses to acetylcholine or bradykinin; however it is not known whether patients with diabetes mellitus show similar alterations. Therefore, we have investigated endothelial function in subcutaneous arteries of normotensive subjects (NT), of patients with essential hypertension (EH), of patients with non-insulin-dependent diabetes mellitus (NIDDM), as well as of patients with both essential hypertension and non-insulin-dependent diabetes mellitus (NIDDM+EH).


METHODS
All subjects were submitted to a biopsy of the subcutaneous fat Small arteries were dissected and mounted on a micromyograph. The media to lumen ratio (M/L) was calculated. A concentration-response curve to acetylcholine, to bradykinin as well as to the endothelium-independent vasodilator sodium nitroprusside were performed. We also evaluated the contractile response to endothelin-1. Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) plasma levels were also measured.


RESULTS
The vasodilatation to acetylcholine and bradykinin (but not to sodium nitroprusside) was significantly and similarly reduced in EH, in NIDDM, and in NIDDM+EH compared with NT. The contractile response to endothelin-1 was similarly reduced in EH, in NIDDM and in NIDDM+EH. Plasma ICAM-1 and VCAM-1 concentrations were higher in EH, NIDDM and NIDDM+EH than in NT.


CONCLUSIONS
An evident endothelial dysfunction was detected in patients with NIDDM, and the simultaneous presence of EH did not seem to exert an additive effect. The contractile responses to endothelin-1 were reduced possibly as a consequence of ET(A) receptor down-regulation.
Rizzoni
D
D
Chair of Internal Medicine Department of Medical and Surgical Sciences, University of Brescia, Italy. rizzoni@master.cci.unibs.it
Porteri
E
E
Guelfi
D
D
Muiesan
M L
ML
Piccoli
A
A
Valentini
U
U
Cimino
A
A
Girelli
A
A
Salvetti
M
M
De Ciuceis
C
C
Tiberio
G A
GA
Giulini
S M
SM
Sleiman
I
I
Monteduro
C
C
Rosei
E A
EA
D001158:Arteries / Q000503:physiopathology*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000503:physiopathology; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D019010:Vascular Cell Adhesion Molecule-1 / Q000097:blood; D014655:Vascular Resistance
D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1