Noninvasive characterization of myocardial blood flow in diabetic, hypertensive, and diabetic-hypertensive rats using spin-labeling MRI.
OBJECTIVE
Microvascular alterations in the diabetic and hypertensive heart are likely to contribute to heart failure. In this work, myocardial blood flow and left ventricular function were measured in vivo in diabetic, hypertensive, and diabetic-hypertensive rats using MRI methods.


METHODS
An 8-week-duration type 1 diabetes was induced by streptozotocin (STZ) in 8 Wistar-Kyoto (WKY) rats (STZ) and in 11 spontaneously hypertensive (SHR) rats (STZ-SHR). Fourteen WKY and 12 SHR served as control and hypertensive groups. Myocardial blood flow quantification was performed using an arterial spin-labeling MRI method. Left ventricular morphology and function were assessed during the same experiment using cine-MRI.


RESULTS
Respective myocardial blood flow values for each group were 6.4 +/- 1.1 (WKY), 6.0 +/- 1.9 (STZ), 5.5 +/- 1.3 (SHR), and 4.3 +/- 0.9 mL. g(-1). min(-1) (STZ-SHR). Myocardial blood flow was significantly decreased in STZ-SHR rats compared with the other groups (p <.05, STZ-SHR vs. all groups). Cine-MRI showed morphological alterations in all pathological groups. No alteration of the ejection fraction was observed in the pathological groups.


CONCLUSIONS
Myocardial blood flow is altered in vivo before any sign of heart failure when rats have type 1 diabetes and hypertension simultaneously. When only one of the pathologies occurs, MBF does not vary significantly.
Iltis
Isabelle
I
Centre de Résonance Magnétique Biologique et Médicale, Faculté de Médecine de Marseille, Marseille, France.
Kober
Frank
F
Dalmasso
Christiane
C
Cozzone
Patrick J
PJ
Bernard
Monique
M
D000818:Animals; D001783:Blood Flow Velocity; D003326:Coronary Circulation; D003921:Diabetes Mellitus, Experimental / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000209:etiology; D006973:Hypertension / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D018810:Magnetic Resonance Angiography; D011859:Radiography; D011877:Radionuclide Imaging; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D013113:Spin Labels
D013113:Spin Labels