0000000000462059
AUTHOR
T. Maarit Lehti
Effects of experimental type 1 diabetes and exercise training on angiogenic gene expression and capillarization in skeletal muscle.
Diabetes alters microvascular structure and function and is a major risk factor for cardiovascular diseases. In diabetic skeletal muscle, impaired angiogenesis and reduced VEGF-A expression have been observed, whereas in healthy muscle exercise is known to have opposite effects. We studied the effects of type 1 diabetes and combined exercise training on angiogenic mRNA expression and capillarization in mouse skeletal muscle. Microarray and real-time PCR analyses showed that diabetes altered the expression of several genes involved in angiogenesis. For example, levels of proangiogenic VEGF-A, VEGF-B, neuropilin-1, VEGFR-1, and VEGFR-2 were reduced and the levels of antiangiogenic thrombospon…
Effects of acute exercise, exercise training, and diabetes on the expression of lymphangiogenic growth factors and lymphatic vessels in skeletal muscle.
Blood and lymphatic vessels together form the circulatory system, allowing the passage of fluids and molecules within the body. Recently we showed that lymphatic capillaries are also found in the capillary bed of skeletal muscle. Exercise is known to induce angiogenesis in skeletal muscle, but it is not known whether exercise has effects on lymphangiogenesis or lymphangiogenic growth factors. We studied lymphatic vessel density and expression of the main lymphangiogenic growth factors VEGF-C and VEGF-D and their receptor VEGFR-3 in response to acute running exercise and endurance exercise training in the skeletal muscle of healthy and diabetic mice. VEGF-C mRNA expression increased after t…
Controlled intermittent shortening contractions of a muscle-tendon complex: muscle fibre damage and effects on force transmission from a single head of a rat
This study was performed to examine effects of prolonged (3 h) intermittent shortening (amplitude 2 mm) contractions (muscles were excited maximally) of head III of rat extensor digitorum longus muscle (EDL III) on indices of muscle damage and on force transmission within the intact anterior crural compartment. Three hours after the EDL III exercise, muscle fibre damage, as assessed by immunohistochemical staining of structural proteins (i.e. dystrophin, desmin, titin, laminin-2), was found in EDL, tibialis anterior (TA) and extensor hallucis longus (EHL) muscles. The damaged muscle fibres were not uniformly distributed throughout the muscle cross-sections, but were located predominantly ne…