| 1. |
- Gan, Li-Ming, 1969, et al.
(författare)
-
Non-invasive real-time imaging of atherosclerosis in mice using ultrasound biomicroscopy
- 2007
-
Ingår i: Atherosclerosis. - : Elsevier BV. - 0021-9150. ; 190:2, s. 313-20
-
Tidskriftsartikel (refereegranskat)abstract
- There are increasing needs to develop imaging techniques to study in vivo vascular morphology and function in various mouse models of atherosclerosis. Using ultrasound biomicroscopy (UBM), we developed and validated a new imaging protocol to follow lesion progression in atherosclerotic mice. ApoE and LDL receptor double knockout mice (DKO) with various degree of atherosclerosis and normal control mice were imaged at the level of the ascending aorta using UBM. Average plaque thickness, as well as plaque area were delineated in the short-axis images, and were subsequently compared with histological measurements. We showed that plaque area at this vascular site was closely correlated to total plaque burden from en face measurement (p<0.0001). UBM-measured plaque thickness and area correlated with indices for histology measures from the same vascular region (p<0.0001 respective p<0.0001). Furthermore, in 16 DKO mice aged from 32 to 35 weeks, UBM showed significantly weekly increases of IMT in the ascending aorta from 0.106+/-0.108 mm at 32 weeks of age to 0.256+/-0.345 mm at 35 weeks of age (p=0.0002). In conclusion, this novel imaging protocol provides us with a non-invasive, accurate and inexpensive way to follow lesion progression in mice in vivo.
|
|
| 2. |
- Grönros, Julia, 1978, et al.
(författare)
-
Proximal to middle left coronary artery flow velocity ratio, as assessed using color Doppler echocardiography, predicts coronary artery atherosclerosis in mice.
- 2006
-
Ingår i: Arteriosclerosis, thrombosis, and vascular biology. - 1524-4636. ; 26:5, s. 1126-31
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: We aimed to establish a completely noninvasive technique to assess coronary artery atherosclerosis in living mice using proximal to middle left coronary artery (LCA) velocity ratio as assessed with color Doppler echocardiography (CDE). METHODS AND RESULTS: Three groups of apolipoprotein E/low-density lipoprotein receptor double-knockout (apoE/LDLr dko) mice 10, 40, and 80 weeks of age and 3 additional age-matched groups of C57BL/6 mice were examined under anesthesia. Coronary flow velocity in proximal (Vprox) and middle part (Vmid) of LCA was measured using CDE. A 40-MHz ultrasound biomicroscope (UBM) was used to visualize lumen and outer vessel diameter in the proximal LCA. Flow velocity in the proximal LCA increased significantly with age and remained constant in the middle part in the apoE/LDLr dko mice, whereas velocities at both the sites remained unchanged in C57 mice. CDE-assessed flow velocity ratio (Vprox/Vmid) increased significantly with age in apoE/LDLr dko mice (P=0.0055) and correlated significantly to percentage wall thickness, as assessed by UBM (P=0.0044; r=0.65) and histology (P=0.0002; r=0.78). Wall thickness increased with age in the apoE/LDLr dko mice as measured with UBM (P=0.0093; r=0.49), which was also confirmed with histology (P<0.0001; r=0.73). CONCLUSIONS: CDE and UBM are useful noninvasive tools to quantify mouse coronary artery atherosclerosis in vivo.
|
|
| 3. |
- Hägg Samuelsson, Ulrika, 1973, et al.
(författare)
-
Voluntary physical exercise and coronary flow velocity reserve: a transthoracic colour Doppler echocardiography study in spontaneously hypertensive rats
- 2005
-
Ingår i: Clin Sci (Lond). - 0143-5221. ; 109:3, s. 325-34
-
Tidskriftsartikel (refereegranskat)abstract
- In the present study, we have developed and demonstrated a coronary artery imaging protocol in rats using transthoracic high-frequency CDE (colour Doppler echocardiography) to investigate the potential direct effects of exercise on CFVR (coronary flow velocity reserve). SHR (spontaneously hypertensive rats) performed voluntary exercise for 6 weeks. Rats were then submitted to ultrasonographic examination and CFVR measurements. The LAD (left anterior descending coronary artery) was visualized using transthoracic CDE in a modified parasternal long-axis view. Doppler measurement was made in mid-LAD during baseline and adenosine-induced hyperaemic condition. Gene and protein expression in cardiac tissue were studied using real-time PCR and immunohistochemistry. Adenosine infusion significantly (P<0.001, as determined by ANOVA) decreased HR, without affecting blood pressure in anaesthetized SHR. A significantly greater adenosine dose-dependent response was seen in exercised rats compared with controls (P=0.02, as determined by ANOVA). The baseline flow velocity in mid-LAD was 0.33+/-0.06 and 0.41+/-0.14 m/s in the exercised and control animals respectively (P value was not significant). The maximum adenosine-induced response was reached at a dose of 140 microg.kg-1 of body weight.min-1, and CFVR averaged at 2.6+/-0.53 and 1.5+/-0.24 in exercised and control animals respectively (P<0.01). Gene expression of CuZnSOD was up-regulated by 21% in exercised animals compared with controls (1.1+/-0.16 compared with 0.89+/-0.09; P<0.01), whereas eNOS expression was unchanged. In conclusion, CFVR in rats can be non-invasively assessed using CDE with high feasibility. Physical exercise is associated with improved CFVR and antioxidative capacity in SHR.
|
|
| 4. |
- Johansson, Maria E, 1977, et al.
(författare)
-
Haemodynamically significant plaque formation and regional endothelial dysfunction in cholesterol-fed ApoE-/- mice
- 2005
-
Ingår i: Clinical Science. - 0143-5221 .- 1470-8736. ; 108:6, s. 531-8
-
Tidskriftsartikel (refereegranskat)abstract
- Flow-mediated vasodilation is suggested as one of the mechanisms involved in arterial expansive remodelling, which is thought to be a defence mechanism in atherogenesis. In the present study, we tested the hypothesis that lumen obstructive plaque formation is associated with failure of NO (nitric oxide)-dependent vasodilation in conduit vessels. Cardiac function and aortic root flow velocities were assessed using high-resolution echocardiography and two-dimensional-guided pulsed Doppler in ApoE(-/-) (apolipoprotein E-deficient) mice fed a standard or high-cholesterol diet. Endothelial function in the proximal and mid-descending aortic regions was studied using a myograph technique. Flow velocity at the aortic root of cholesterol-fed ApoE(-/-) mice was significantly increased as a result of lumen narrowing, detected via histological analysis. NO-dependent vasodilatory responses were selectively impaired in the atherosclerosis-prone vascular regions in cholesterol-fed ApoE(-/-) mice. In conclusion, consumption of a high-cholesterol diet results in lumen obstructive plaque formation in ApoE(-/-) mice, which significantly alters aortic root haemodynamics. This phenomenon is associated with impaired NO-dependent vasodilation in vessel segments known to be prone to atherosclerosis.
|
|
