Correlation of functional and structural alterations of the coronary arterioles during development of type II diabetes mellitus in rats.
OBJECTIVE
Cardiac complications in diabetes mellitus (DM) are frequently ascribed to microangiopathy. Therefore, we sought to directly correlate the serial changes in coronary arterial function with the extent of coronary arteriolar remodeling in a model spontaneously developing type II DM.


METHODS
Otsuka Long-Evans Tokushima Fatty (OLETF) rats and control Long-Evans Tokushima Otsuka (LETO) rats were used. At 5, 15 and 30 weeks of age, ten rats in each group were subjected to systemic and coronary hemodynamic measurements using the colored microsphere technique before and during maximal coronary hyperemia and histological assessment with Azan-Mallory stain of the coronary arterioles.


RESULTS
As early as 15 weeks of age, at which time fasting plasma glucose concentration remained normal, OLETF rats exhibited a lower coronary flow reserve and a greater coronary vascular resistance during hyperemia than did LETO rats. On histomorphometry, OLETF rats exhibited a greater wall-to-lumen ratio and a greater degree of perivascular fibrosis of arterioles at 15 weeks of age and thereafter, both of which exhibited a significant correlation with the minimal coronary vascular resistance.


CONCLUSIONS
The degree of functional deterioration in coronary circulation was directly correlated with the severity of coronary arteriolar structural remodeling during the development of microangiopathy in early stage of DM.
Yu
Yang
Y
Second Department of Internal Medicine, Kagawa Medical University, 1750-1 Ikenobe, Miki-cho, Kita-gun, 761-0793, Kagawa, Japan.
Ohmori
Koji
K
Kondo
Isao
I
Yao
Li
L
Noma
Takahisa
T
Tsuji
Teppei
T
Mizushige
Katsufumi
K
Kohno
Masakazu
M
D000818:Animals; D001160:Arterioles / Q000473:pathology / Q000503:physiopathology; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D003327:Coronary Disease / Q000473:pathology / Q000503:physiopathology*; D003331:Coronary Vessels / Q000473:pathology / Q000503:physiopathology*; D003921:Diabetes Mellitus, Experimental / Q000473:pathology / Q000503:physiopathology*; D003924:Diabetes Mellitus, Type 2 / Q000473:pathology / Q000503:physiopathology*; D003925:Diabetic Angiopathies / Q000473:pathology / Q000503:physiopathology*; D018450:Disease Progression; D006352:Heart Ventricles / Q000473:pathology; D006439:Hemodynamics; D008297:Male; D009929:Organ Size; D051381:Rats; D020334:Rats, Inbred OLETF; D011919:Rats, Inbred Strains
D001786:Blood Glucose