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Autopsy Cardiac Examination
Published in Mary N. Sheppard, Practical Cardiovascular Pathology, 2022
The heart is supplied by a rich plexus of lymphatics. The lymphatic channels run along with the veins and drain the lymph to the pulmonary hilar lymph nodes and also directly into the thoracic duct and the left lymphatic channel. As part of the circulatory system, lymphatic vessels have particular functions in fluid homeostasis, lipid absorption, immune cell trafficking and causative agent filtration. The lymphatic vascular system consists of a compact network of blind-ended, slight-walled lymphatic capillaries and collecting lymph vessels that drain exudative protein-rich fluid from the majority of tissues that transport the lymph by way of the thoracic duct to the venous circulation. Several lymphatic endothelial markers, such as vascular endothelial growth factor receptor 3 (VEGFR-3), lymphatic vessel endothelial hyaluronic acid receptor-1 (LYVE-1), prospero-related homeobox-1 (Prox-1) and podoplanin (D2-40) are widely used in labelling lymphatics (Fig. 1.16).
Endothelial cell dysfunction and pre-eclampsia
Published in Pankaj Desai, Pre-eclampsia, 2020
All secretions and releases from these cells consequently have direct access to the entire body through blood. In turn, they also have a vulnerability. Because of this strategic location and resultant access to diverse circulating substances, endothelial cells can directly modulate the tone of the vessels. Along with this, they also modulate the processes of coagulation and vascular permeability. Vascular tone is maintained by endothelial cells striking a balance between the circulating vasodilatory and vasoconstrictive substances. The body needs a potent, well-balanced and well-toned vascular system. It achieves this by modulating the tone of the vessel musculature. As has been previously mentioned, the blood does not come in direct contact with vessel walls and, therefore, is relatively remote from the smooth muscles lining them. Endothelial cells are interceding between the vessel walls and the circulating blood column.
Renal, Cardiovascular, and Pulmonary Functions of Dopamine
Published in Nira Ben-Jonathan, Dopamine, 2020
The circulation system is functionally divided into two main vascular beds: pulmonary and systemic. The pulmonary circulation moves blood from the heart to the lungs, where it absorbs oxygen and releases carbon dioxide. The oxygenated blood then flows back to the heart and from there to the rest of the body via the systemic circulation. The vascular system is composed of three major types of blood vessels: arteries, which carry blood away from the heart; capillaries, responsible for exchange of water and chemicals between blood and tissues; and veins, which carry blood from the capillaries back toward the heart. As shown in Figure 7.7, the various types of blood vessels differ in diameter and in cytoarchitecture. Blood vessels do not actively engage in the transport of blood given that they have no appreciable peristalsis. Instead, blood is propelled through the arteries and arterioles by pressure generated by the heartbeat. However, arteries and, to a limited degree, veins can regulate their inner diameter by contraction of the vascular smooth muscle cells (VSMCs). Local vasoconstriction and vasodilation can then change the blood flow to downstream organs.
Lycopene alleviates oxidative stress-induced cell injury in human vascular endothelial cells by encouraging the SIRT1/Nrf2/HO-1 pathway
Published in Clinical and Experimental Hypertension, 2023
Wenhai Guo, Danping Huang, Shaodong Li
In the past few years, oxidative stress has been widely involved in many disease processes, including myocardial infarction, atherosclerosis, myocardial ischemia-reperfusion injury, and other cardiovascular diseases (30,31). H2O2, as a major redox metabolite, is essential in redox sensing, signaling, and redox regulation. Supraphysiological concentrations of H2O2 can cause damage to cellular functions, resulting in oxidative stress damage (32). Vascular endothelial cells are an important part of the heart and vascular system, and the nutrition and proper biochemical function of vascular endothelial cells are related to the proper functioning of cardiovascular function (33). The accumulation of ROS in endothelial cells under oxidative stress stimuli induces endothelial dysfunction, which has a major impact on the cardiovascular system and the health of living organisms (34). In the present study, to mimic vascular endothelial cell oxidative stress injury in cardiovascular disease, we used a high concentration of H2O2 to stimulate HMEC-1 and ECV-304 cells. The results showed an increase in ROS and MDA production and a decrease in GSH, GCLC, and GCLM expression in the cells under H2O2 stimulation. Among them, MDA can be used as a marker of oxidative stress damage. In addition, there are antioxidant stress injury substances in the cell, such as GSH as well as other enzyme class and non-enzyme class substances, which can alleviate the oxidative stress injury (35).
Lymphatic targeting for therapeutic application using nanoparticulate systems
Published in Journal of Drug Targeting, 2022
Nidhi Singh, Mayank Handa, Vanshikha Singh, Prashant Kesharwani, Rahul Shukla
The lymphatic system was first recognised by Gasparo Aselli in the seventeenth century as per ancient text reports. It was later in the eighteenth century when various aspects of lymphatic system including its anatomy, got its attention and significance. Vascular system is further compartmentalised into lymphatic system that encompass different convoluted web of channels and hold a clear liquid termed lymph. Lymphatic system is composed of lymphatic duct, lymphatic capillaries, lymphatic vessel and some lymphatic organs including spleen and lymph node. Lymphatic vessels carry a clear watery fluid lymph, and white blood cells. Furthermore, lymphatic system is widely distributed in other parts of body in the form of lymph nodes, which is present in the neck, chest, armpit, groyne, abdomen. Lymphatic system maintains homeostasis and protection of the body tissues against different bacterial and viral infection by the mechanism of filtration. The lymphatic system not only filters the elements from lymph but avoid the first-pass hepatic metabolism of drugs directly via intestinal uptake [1]. This property plays an important role in tissue defense against infections by promoting the lymphocytic activity which in turn provides immunity or resistance. As mentioned, one of the major roles of the lymphatic system is to maintain water homeostasis in the body by recurring fluids present outside the body and oozing out into the blood circulation. It also enhances the absorption of antibiotics, water-insoluble vitamins, long-chain fatty acid and cholesterol ester.
The emerging significance of circadian rhythmicity in microvascular resistance
Published in Chronobiology International, 2022
Jeffrey T. Kroetsch, Darcy Lidington, Steffen-Sebastian Bolz
On a simplistic level, the vascular system is separated into a macro- and a microvascular component, each with distinct functional characteristics: macrovessels conduct blood over long distances with minimal resistance (conduit vessels), while microvessels are specialized to control blood flow resistance and interface with highly specialized microenvironments within various tissues. Since the tissue microenvironments are unique, it is not surprising that the microvascular elements within each tissue are also highly specialized. For example, the renal microcirculation permits the passage of molecules and fluids, while the cerebral microcirculation is largely impermeable (i.e., blood–brain barrier). Thus, it is important to recognize that molecular control mechanisms identified in one particular microvascular bed cannot be assumed to operate in another microvascular bed. Collectively, the microvascular resistance generated by the resistance arteries and pre-capillary arterioles locally controls capillary blood flow and hence, tissue/organ perfusion. The sum of the resistances generated by each microvascular bed constitutes the variable component of total peripheral resistance (TPR).