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K S Pieper

Publications and source records attributed to K S Pieper.

At least 73 records · Page 4Linked to original sources
PubMed1986

Characteristics of muscle-cellular adaptation to intense physical loads.

We studied the influence of a 5-weeks training program, mainly with intense work-loads in form of explosive power, on the skeletal muscle system in 7 male sports students. Muscle biopsy specimens from m. vastus lateralis were analysed histochemically, biochemically and by means of electron microscopy. After the training of several weeks, a clear hypertrophy of FT-fibres (24%, p less than 0.05) and ST-fibres (20%, p less than 0.05) became evident. The fibre composition was not affected by the training program. The increase of mean cross-sectional areas of muscle fibres was not connected with any shifting of volume proportions of cellular compartments (volume density of mitochondria, myofibrils and sarcoplasm) at ultrastructural level. Only in the peripheric fibre region mitochondrial volume density increased from 5.9 +/- 2.5 to 8.3 +/- 1.2% in tendency. Contrary to endurance athletes and untrained subjects, power athletes show higher values of sarcoplasmic volume density in their muscle fibres. Results will be discussed in connection with specific demands of explosive powerful muscular performances.

Adaptation, Physiological↗
PubMed1985

[Changes in the fine structure of the masseter muscle as affected by unilateral occlusal disorders].

Biopsy specimens from the masseter muscle of the miniature pig "Mini-LEWE" were analysed histochemically before and after unilateral occlusal disturbances. The percentages of different fibre types and the cross-sectional area of fibres were determined with the myosin-ATPase reaction after acid preincubation. The capillary membranes were visualized by means of modified PAS-reaction. There was demonstrated a significant increase from the percentage portion of ST-fibre types, especially of the side of occlusal disturbance, under experimental conditions. This indicates an increased isometric contraction of the masseter muscle. The size of FT-fibre types and the capillarity increase significantly on the side without occlusal disturbances, due to the dislocation of the masticatory efforts to this side. The masseter muscle fine structure is shown to be adapted good to the disturbed functional conditions. No significant side differences were found in the dry mass of the masticatory muscles, at the end of experiments.

Animals↗
PubMed1984

[Skeletal muscle reaction to the loading limit. III. Changes in the contractile apparatus].

A description is given of the changes in the contractile apparatus of the skeletal muscle following extreme long-term exercise. In detail, they include Z-stripe dehiscences, myofibril disintegrations and destructions of single sarcomer . These findings are known from myopathology . A characteristic feature is their subsarcolemmic localisation. The pathogenesis is discussed. In connection with the alterations of the sarcolemma and the mitochondria as well as the increased endo- and exocytosis of the muscle fibre, the cause is seen in a local intracellular catabolism. At the same time, the possible importance to the effluence of enzymes, especially of creatine phosphokinase, is pointed out.

Adult↗