Search results for " Muscle"
showing 10 items of 1495 documents
Mitochondrial biogenesis in exercise and in ageing☆
2009
Mitochondrial biogenesis is critical for the normal function of cells. It is well known that mitochondria are produced and eventually after normal functioning they are degraded. Thus, the actual level of mitochondria in cells is dependent both on the synthesis and the degradation. Ever since the proposal of the mitochondrial theory of ageing by Jaime Miquel in the 70's, it was appreciated that mitochondria, which are both a target and a source of radicals in cells, are most important organelles to understand ageing. Thus, a common feature between cell physiology of ageing and exercise is that in both situations mitochondria are critical for normal cell functioning. Mitochondrial synthesis i…
Exercise and antioxidant supplements in the elderly
2013
Abstract Both exercise and aging increase reactive oxygen species (ROS), which can result in damage to cells. Aging is the result of damage caused by ROS to the mitochondrial genome in post mitotic cells and numerous studies have demonstrated an increase in ROS or their byproducts with exercise. ROS can cause oxidative stress as they overwhelm the antioxidant cellular defenses. Therefore interventions aimed at limiting or inhibiting ROS production, such as supplementation with antioxidant vitamins, should be able to reduce fatigue during muscle contraction and the rate of formation of aging changes with a consequent reduction of the aging rate and disease pathogenesis. However, it has been …
Interplay of oxidants and antioxidants during exercise: Implications for muscle health
2010
Muscle contraction results in generation of reactive oxygen and nitrogen species (RONS) at a rate determined by the intensity, frequency, and duration of the exercise protocols. Strenuous exercise causes oxidation of protein, lipid, and DNA, release of cytosolic enzymes, and other signs of cell damage; however, only exhaustive exercise is detrimental. Indeed, the regulation of vascular tone, the excitation-contraction coupling, growth, and differentiation in skeletal muscle, are governed in part by RONS. This is accomplished by RONS interaction with redox-sensitive transcription factors, leading to increased gene expression of antioxidant enzymes, cytoprotective proteins, and other enzymes …
Identification and characterization of the nano-sized vesicles released by muscle cells
2013
AbstractSeveral cell types secrete small membranous vesicles that contain cell-specific collections of proteins, lipids, and genetic material. The function of these vesicles is to allow cell-to-cell signaling and the horizontal transfer of their cargo molecules. Here, we demonstrate that muscle cells secrete nano-sized vesicles and that their release increases during muscle differentiation. Analysis of these nanovesicles allowed us to characterize them as exosome-like particles and to define the potential role of the multifunctional protein Alix in their biogenesis.
Storage Diseases: Diagnostic Position
2013
Storage diseases are metabolic multiorgan conditions, which may be divided into lysosomal and nonlysosomal diseases. Disorders of the lysosomal type require electron microscopy for morphological diagnosis. It is the metabolic substrate that determines involvement of the cell type or organ in the individual storage disease, allowing extracerebral biopsies, for instance, in the neuronal ceroid-lipofuscinoses (NCL). A hierarchy of tissues biopsied for diagnosis can be based on easy accessibility: blood lymphocytes, skin, conjunctiva, rectum, skeletal muscle. Lysosomal diseases are divided into vacuolar and nonvacuolar ones. NCL display variegated ultrastructural patterns. Drugs may induce lyso…
Diagnostic morphology of human eye-related storage disorders
1989
While retina and other ocular tissues are involved clinically and morphologically in a variety of lysosomal disorders, it is only the conjunctiva that is accessible by biopsy to morphological, i.e., electron microscopic recognition of the patient's individual lysosomal disease. However, this procedure is not utilized by many. Instead, skin and circulating lymphocytes are the most frequently obtained tissues for diagnostic investigation, as skin contains an abundance of diversified cell types for morphological examination and simultaneously fibroblasts to be cultured for biochemical investigation. It is the tissue most suitable for identifying lysosomal disorders and parallels in diagnostic …
Endothelial Nitric Oxide Synthase
2007
Endothelial nitric oxide synthase (eNOS; also referred to as NOS3 or NOSIII), a low output enzyme is the prototypical isoform being found in endothelial cells. This isoform (like nNOS) synthesizes NO in a short-lasting, pulsatile, Ca++/calmodulin-activated manner. Endothelium-derived NO is a physiologically significant vasodilator and inhibitor of platelet aggregation and adhesion. In addition, vascular NO can prevent leukocyte adhesion to the endothelium by down-regulating the leukocyte adhesion glycoprotein complex CD11/CD18. Finally, endothelial NO has also been shown to inhibit the proliferation of vascular smooth muscle cells. Therefore, endothelial NO is likely to represent a protecti…
Procedure to consistently obtain endothelial and smooth muscle cell cultures from umbilical cord vessels
2006
The prenatal history of an individual can be responsible to some extent for the occurrence of several diseases later in life. Thus, low birth weight has been related to an increased risk of developing hypertension or type 2 diabetes. The molecular and cellular basis of this increased risk could be found in body fluids and cell types that can be obtained just after birth. To get this unique information, a methodology was developed to consistently obtain cultures of 4 cell types, endothelial and smooth muscle cells from both the vein and the arteries present in the umbilical cord of an individual. From 21 umbilical cords processed, 82 of the 84 possible cell cultures were obtained. The cell c…