Iltis Isabelle, Kober Frank, Dalmasso Christiane, Cozzone Patrick J, Bernard Monique
Centre de Résonance Magnétique Biologique et Médicale, Faculté de Médecine de Marseille, Marseille, France.
Microcirculation. 2005 Dec;12(8):607-14. doi: 10.1080/10739680500301607.
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.
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.
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.
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.
糖尿病和高血压性心脏病中的微血管改变可能导致心力衰竭。在本研究中，使用磁共振成像（MRI）方法在体内测量糖尿病、高血压以及糖尿病合并高血压大鼠的心肌血流量和左心室功能。
通过链脲佐菌素（STZ）诱导8只Wistar-Kyoto（WKY）大鼠（STZ组）和11只自发性高血压大鼠（SHR）（STZ-SHR组）患1型糖尿病，病程8周。14只WKY大鼠和12只SHR大鼠分别作为对照组和高血压组。采用动脉自旋标记MRI方法进行心肌血流量定量分析。在同一实验中，使用电影MRI评估左心室形态和功能。
每组各自的心肌血流量值分别为6.4±1.1（WKY组）、6.0±1.9（STZ组）、5.5±1.3（SHR组）和4.3±0.9 mL·g⁻¹·min⁻¹（STZ-SHR组）。与其他组相比，STZ-SHR组大鼠的心肌血流量显著降低（p<.05，STZ-SHR组与所有其他组相比）。电影MRI显示所有病理组均有形态学改变。病理组未观察到射血分数的改变。
当大鼠同时患有1型糖尿病和高血压时，在出现任何心力衰竭迹象之前，体内心肌血流量就已发生改变。当仅出现其中一种病变时，心肌血流量无显著变化。
