Morphological and biomechanical study of abdominal aorta of rats submitted to experimental chronic alcoholism

Assessment of therapeutic efficacy of adipose tissue-derived mesenchymal stem cells administration in hyperlipidemia-induced aortic atherosclerosis in adult male albino rats

Atherosclerosis (AS) is a common disease seriously detrimental to human health. AS is a chronic progressive disease related to inflammatory reactions. The present study aimed to characterize and evaluate the effects of adipose tissue stem cells (ADSCs) in high-fat diet-induced atherosclerosis in a rat model. The present study comprises thirty-six rats and they were divided into three groups: the control group, the high-fat diet (HFD) group; which received a high-fat diet, and the high-fat diet + stem cells (HFD+SC) group; which was fed with a high-fat diet along with the administration of intravenous ADSCs. Food was given to the animals for 20 weeks to establish dyslipidemia models. After 20 weeks, animals were sacrificed by cervical dislocation; blood was collected to measure total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL); aortae were collected to detect morphologic changes. Rats of the HFD group showed a significant increase in body weight (B.Wt), altered lipid profile increased expression of inducible nitric oxide synthase (iNOS), and decreased expression of endothelial nitric oxide synthase (eNOS). However, in HFD+SC there was a significant decrease in body weight gain and an improvement in lipid profile. Histopathological and ultrastructural variations observed in the aorta of the HFD group when treated with ADSCs showed preserved normal histological architecture and reduced atherosclerosis compared with the HFD group. This was evidenced by laboratory, histological, immunohistochemical, and morphometric studies. Thus, ADSCs reduced TC, TG, and LDL, reduced the expression of iNOS, and increased the expression of eNOS. The high-fat diet was likely to cause damage to the wall of blood vessels. Systemically transplanted ADSCs could home to the aorta, and further protect the aorta from HFD-induced damage.

The crosstalk between arterial components and the bioresorbable, 3-D printed poly-l-lactic acid scaffolds

Bioresorbable scaffolds (BRS) are designed to provide a temporary support that subsequently leaves behind native vessels after their complete degradation. The accumulation of mechanical changes influences the vascular histological characteristics...

Acute aortic wall injury caused by aortic cross-clamping: morphological and biomechanical study of the aorta in a swine model of three aortic surgery approaches

Background

Aortic cross-clamping and balloon occlusion of the aorta could lead to damage to the aorta wall.

Objective

The aim of this study was to investigate changes to the aorta wall related to the method used to interrupt flow (clamping or balloon) in the different techniques available for aortic surgery.

Methods

Experiments were performed on 40 female pigs, weighing 25-30kg, which were randomly allocated to 4 study groups: S (n=10), no intervention (sham group); C (n=10), midline transperitoneal laparotomy for infrarenal abdominal aortic access with 60 min of cross-clamping; L (n=10), laparoscopic infrarenal abdominal aortic surgery with 60 min of cross-clamping; EV (n=10), remote proximal aortic control with transfemoral arterial insertion of aortic occlusion balloon catheter, inflated to provide continued aortic occlusion for 60min. After euthanasia, the aortas were removed and cross-sectioned to obtain histological specimens for light microscopic and morphometric analyses. The remaining longitudinal segments were stretched to rupture and mechanical parameters were determined.

Results

We observed a reduction in the yield point of the abdominal aorta, decrease in stiffness and in failure load in the aortic cross-clamping groups (C and L) compared with the EV group.

Conclusions

Aortic cross-clamping during open or laparoscopic surgery can affect the mechanical properties of the aorta leading to decrease in resistance of the aorta wall, without structural changes in aorta wall histology.

Things may not go as planned: The role of aortoiliac dilation and elongation during the estimation vascular structures' anatomical course

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Variation of aortic morphology such as aortic dimensions, branching points, and correlation with adjacent structures is highlighted.

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The mechanism of variance relies on the diseases such as arteriosclerosis, syphilis and hypertension.

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Patients with hypertension, atherosclerosis, and aortic aneurysm should be excluded from the study because of the variation of aortic morphology is concluded.

Vitamin D induces increased systolic arterial pressure via vascular reactivity and mechanical properties

Background/Aims

The aim of this study was to evaluate whether supplementation of high doses of cholecalciferol for two months in normotensive rats results in increased systolic arterial pressure and which are the mechanisms involved. Specifically, this study assesses the potential effect on cardiac output as well as the changes in aortic structure and functional properties.

Methods

Male Wistar rats were divided into three groups: 1) Control group (C, n = 20), with no supplementation of vitamin D, 2) VD3 (n = 19), supplemented with 3,000 IU vitamin D/kg of chow; 3) VD10 (n = 21), supplemented with 10,000 IU vitamin D/kg of chow. After two months, echocardiographic analyses, measurements of systolic arterial pressure (SAP), vascular reactivity, reactive oxygen species (ROS) generation, mechanical properties, histological analysis and metalloproteinase-2 and -9 activity were performed.

Results

SAP was higher in VD3 and VD10 than in C rats (p = 0.001). Echocardiographic variables were not different among groups. Responses to phenylephrine in endothelium-denuded aortas was higher in VD3 compared to the C group (p = 0.041). Vascular relaxation induced by acetylcholine (p = 0.023) and sodium nitroprusside (p = 0.005) was impaired in both supplemented groups compared to the C group and apocynin treatment reversed impaired vasodilation. Collagen volume fraction (<0.001) and MMP-2 activity (p = 0.025) was higher in VD10 group compared to the VD3 group. Elastin volume fraction was lower in VD10 than in C and yield point was lower in VD3 than in C.

Conclusion

Our findings support the view that vitamin D supplementation increases arterial pressure in normotensive rats and this is associated with structural and functional vascular changes, modulated by NADPH oxidase, nitric oxide, and extracellular matrix components.

Alcoholism and traumatic subarachnoid hemorrhage: an experimental study on vascular morphology and biomechanics

BACKGROUND

Traumatic subarachnoid hemorrhage (TSAH) related to alcohol abuse is a notable risk factor. Here, we investigated the vascular morphology and biomechanics of TSAH in rat models of acute alcoholic intoxication and chronic alcoholism rats to explore the possible mechanisms of TSAH.

METHODS

Sixty male Sprague-Dawley rats were divided into acute alcoholic intoxication and chronic alcoholism groups. Edible spirituous liquor (56% vol/vol) was intragastrically given (15 mL/kg) once to the rats in the acute group, and given twice daily (8 mL/kg for 2 weeks and 12 mL/kg for another 2 weeks) to rats in the chronic group. A self-made instrument was used to inflict head injury. Whole brain, arterial blood, and thoracic aorta of rats were sampled for morphologic and biomechanical examination.

RESULTS

Compared with the acute alcoholic rats, the chronic alcoholic rats showed significant morphologic and biomechanical changes: (1) decreased body weight (p<0.05), (2) higher morbidity and mortality from TSAH (p<0.01), (3) greater mean thickness of vascular wall of subarachnoid small arteries and each layer thickness of thoracic aorta (p<0.05), (4) decreased failure load and corresponding extensibility (60 kPa and limit load) of thoracic aorta, and (5) increased elastic modulus (30 kPa, range in physiologic stress) (p<0.05).

CONCLUSIONS

Chronic alcoholism can induce the morphologic and biomechanical changes in cerebral vessels and thoracic aorta. The synergistic effect of alcohol abuse and minor blow may be one of the mechanisms of TSAH. High blood pressure from long-term alcohol abuse is also a notable factor.