A Tireless Giant in Vascular Research

Effects of granulocyte colony‑stimulating factor on rabbit carotid and porcine heart models of chronic obliterative arterial disease

Previous studies suggest that granulocyte colony-stimulating factor (G-CSF) can promote bone marrow derived progenitor cells to mediate cardiovascular repair, potentially reversing mechanical dysfunction in chronic ischaemic heart disease and post myocardial infarction. Two models were used in the present study both using a surgical ameroid constrictor to induce arterial stenosis. The first model used the carotid artery of rabbits. They were divided into high fat diet (inducing atherosclerosis) or normal fat diet (control) groups. Each was subdivided into surgical exposure group without constrictor, ameroid constrictor receiving normal saline or receiving G-CSF 15 µg/kg/day. Endothelial markers of endothelial nitric oxide synthase and endothelin 1 were increased by the use of ameroid constrictor in both atherosclerotic and non-atherosclerotic mice, however were not further altered by G-CSF. Scanning electron microscopy indicated that ameroid constrictor application altered endothelial morphology from an oval shape to a round shape and this was more prominent in the atherosclerotic compared with the non-atherosclerotic group. G-CSF injection increased the number of endothelial cells in all groups. The second model used the left coronary artery of pigs. They were equally divided into following groups, receiving normal saline (control), G-CSF 2.5 µg/kg/day (low dose), 5 µg/kg/day (medium dose) and 10 µg/kg/day (high dose) for 5 days. G-CSF at a low or high dose worsened intimal hyperplasia however at a medium dose improved it. In conclusion, G-CSF had no effect in a rabbit carotid artery model of atherosclerosis. Its effects on the porcine heart were dose-dependent; arterial disease worsened at a low or high dose, but improved at a medium dose.

Isolated heart models for studying cardiac electrophysiology: a historical perspective and recent advances

Experimental models used in cardiovascular research range from cellular to whole heart preparations. Isolated whole hearts show higher levels of structural and functional integration than lower level models such as tissues or cellular fragments. Cardiovascular diseases are multi-factorial problems that are dependent on highly organized structures rather than on molecular or cellular components alone. This article first provides a general introduction on the animal models of cardiovascular diseases. It is followed by a detailed overview and a historical perspective of the different isolated heart systems with a particular focus on the Langendorff perfusion method for the study of cardiac arrhythmias. The choice of species, perfusion method, and perfusate composition are discussed in further detail with particular considerations of the theoretical and practical aspects of experimental settings.

Mouse models of atherosclerosis: a historical perspective and recent advances

Atherosclerosis represents a significant cause of morbidity and mortality in both the developed and developing countries. Animal models of atherosclerosis have served as valuable tools for providing insights on its aetiology, pathophysiology and complications. They can be used for invasive interrogation of physiological function and provide a platform for testing the efficacy and safety of different pharmacological therapies. Compared to studies using human subjects, animal models have the advantages of being easier to manage, with controllable diet and environmental risk factors. Moreover, pathophysiological changes can be induced either genetically or pharmacologically to study the harmful effects of these interventions. There is no single ideal animal model, as different systems are suitable for different research objectives. A good understanding of the similarities and differences to humans enables effective extrapolation of data for translational application. In this article, we will examine the different mouse models for the study and elucidation of the pathophysiological mechanisms underlying atherosclerosis. We also review recent advances in the field, such as the role of oxidative stress in promoting endoplasmic reticulum stress, mitochondrial dysfunction and mitochondrial DNA damage, which can result in vascular inflammation and atherosclerosis. Finally, novel therapeutic approaches to reduce vascular damage caused by chronic inflammation using microRNA and nano-medicine technology, are discussed.