Short-term bone biochemical response to a single bout of high-impact exercise.

Bone response to a single bout of exercise can be observed with biochemical markers of bone formation and resorption. The purpose of this study was to examine the response of bone biochemical markers to a single bout of exhaustive high-impact exercise. 15 physically active young subjects volunteered to participate.

Collagen synthesis and degradation in polyneuropathy and myopathies.

To determine the mechanisms underlying the changes in collagen metabolism responsible for muscle fibrosis in patients with neuromuscular diseases, the synthesis and degradation of collagens was studied in muscles of patients with polyneuropathy and noninflammatory myopathies. The mRNA levels for type I, III, and IV collagens and immunohistochemical staining intensities for collagen propeptides and telopeptides were increased in polyneuropathy, suggesting enhanced synthesis of collagens. In myopathy, the mRNA levels were at the control level.

Determinants of lower-body muscle power in early postmenopausal women.

Objectives: To investigate the association between muscle size, density, and fiber composition; body composition; maximal isometric knee extension strength (KES); and lower-body muscle power in healthy postmenopausal women.

Design: Cross-sectional analysis of baseline data from a 1-year randomized controlled experiment.

Setting: University-based research laboratory.

Short-term effects of forced eccentric contractions on collagen synthesis and degradation in rat skeletal muscle.

Acute downhill running has been shown to activate matrix metalloproteinase- (MMP-) 2 and to change type IV collagen concentration in some muscle types. In order to study the influence of more intense exercise on total collagen and type IV collagen concentrations, molecules regulating their synthesis and degradation were investigated after forced lengthening contractions in rat skeletal muscle. Tibialis anterior (TA) muscle of 24 male Wistar rats was subjected to 240 forced lengthening contractions.