Age-related myofiber atrophy in old mice is reversed by ten weeks voluntary high-resistance wheel running.

Objective: Age-related loss of muscle mass and function can be attenuated in rodents with life-long voluntary wheel running with moderate resistance. The present study assessed if sarcopenia could be counteracted with ten weeks high intensity training.

Method: Old (22-23 months) and middle-aged (11 months) mice were divided into three physical activity groups: Ten weeks of voluntary running in wheels with high (HR) or low resistance (LR), or no running wheel (SED).

The influence of fibrillin-1 and physical activity upon tendon tissue morphology and mechanical properties in mice.

Fibrillin-1 mutations cause pathological changes in connective tissue that constitute the complex phenotype of Marfan syndrome. In this study, we used fibrillin-1 hypomorphic and haploinsufficient mice (Fbn1 and Fbn1 mice, respectively) to investigate the impact of fibrillin-1 deficiency alone or in combination with regular physical activity on tendon tissue morphology and mechanical properties. Morphological and biomechanical analyses revealed that Fbn1 but not Fbn1 mice displayed smaller tendons with physical properties that were unremarkable when normalized to tendon size.

Skin autofluorescence is associated with arterial stiffness and insulin level in endurance runners and healthy controls - Effects of aging and endurance exercise.

Background: Life-long regular endurance exercise yields positive effects on cardiovascular and metabolic function, disease and mortality rate. Glycation may be a major mechanism behind age-related diseases. However, it remains unknown if skin autofluorescence (SAF), which reflects glycation, is related to arterial and metabolic function in life-long endurance runners and sedentary controls.

Functional adaptation of tendon and skeletal muscle to resistance training in three patients with genetically verified classic Ehlers Danlos Syndrome.

Background: tendon and skeletal muscle function adapts to physical training of resistive nature, but it is unknown to what extent persons with genetically altered connective tissue - who have a higher than normal tendon extensibility - will obtain any effect upon their tendon and muscle when undergoing muscle strength training. We investigated patients with classical Ehlers Danlos Syndrome (EDS) (collagen type V defect) who display articular hypermobility, skin extensibility and tissue fragility.

Methods: subjects underwent strength training 3 times a week for 4 months and were tested before and after intervention in regards to muscle strength, tendon mechanical properties, and muscle function.

Glutaraldehyde cross-linking of tendon--mechanical effects at the level of the tendon fascicle and fibril.

Conclusive insight into the microscopic principles that govern the strength of tendon and related connective tissues is lacking and the importance of collagen cross-linking has not been firmly established. The combined application of whole-tissue mechanical testing and atomic force spectroscopy allowed for a detailed characterization of the effect of cross-linking in rat-tail tendon. The cross-link inducing agent glutaraldehyde augmented the tensile strength of tendon fascicles.