Stefan Galler

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1. Contractile properties were investigated on single skinned-fibre preparations from rat leg muscles. Following the mechanical measurements, the myosin heavy chain (HC) composition of the same fibre was analysed by gradient gel electrophoresis. 2. Fibres were typed according to their myosin HC isoform composition (HCI, type I; HCIIA, type IIA; HCIID, type(More)
The underlying mechanism of stretch-induced delayed force increase (stretch activation) of activated muscles is unknown. To assess the molecular correlate of this phenomenon, we measured stretch activation of single, Ca2+-activated skinned muscle fibres from rat, rabbit and the human and analysed their myosin heavy chain complement by SDS gradient gel(More)
Each skeletal muscle of the body contains a unique composition of "fast" and "slow" muscle fibers, each of which is specialized for certain challenges. This composition is not static, and the muscle fibers are capable of adapting their molecular composition by altered gene expression (i.e., fiber type conversion). Whereas changes in the expression of(More)
In rabbit, rat and human skinned skeletal muscle fibres the length-time relationship of isotonic releases was determined after maximal Ca2+ activation. Slack test experiments provided information about unloaded conditions. Force clamp experiments of different load were extrapolated for zero load and compared with the slack test data. The course length-time(More)
Cross-bridge kinetics underlying stretch-induced force transients was studied in fibres with different myosin light chain (MLC) isoforms from skeletal muscles of rabbit and rat. The force transients were induced by stepwise stretches (< 0.3% of fibre length) applied on maximally Ca2+-activated skinned fibres. Fast fibre types IIB, IID (or IIX) and IIA and(More)
The free intracellular Mg2+ concentration ([Mg2+]i) was investigated in frog sartorius and crayfish phasic and tonic skeletal muscle fibres, using a new Mg2+-sensitive microelectrode based on the ionophore ETH 5214 [Hu et al. (1989) Anal Chem 61:574–576]. In Ringer solution containing 0.5 mmol/l MgCl2, the mean [Mg2+]i of the frog muscle fibres was 1.3(More)
Isometric force responses following flash photolysis of caged-ATP were measured from skinned preparations of the catch muscle anterior byssus retractor of Mytilus (ABRM). When fibres were transferred from Ca2+-free to Ca2+-containing rigor solution (pCa<4) the force remained low, but flash photolysis produced an extended force increase (half-time, 0.30±0.07(More)
Phosphorylation of twitchin is known to abolish the catch state of anterior byssus retractor muscle (ABRM) of the bivalve mollusc Mytilus edulis. To investigate the role of myosin head involvement in force maintenance during catch, the effect of twitchin phosphorylation on myosin head detachment was studied in saponin-skinned fibre bundles of ABRM. The(More)
matidia. We therefore conjecture that the coexistence of different types of ommatidia is a common feature of the butterfly retina. How the different ommatidia are arranged, and what their function is for color vision remain to be further investigated. We thank Dr. D.G. Stavenga for critical reading of the manuscript. This work was supported by the Whitehall(More)
Single fibres of three different types, which had been characterized histochemically with regard to differences in myofibrillar adenosine triphosphatase (ATPase) activity and its pH stability, were microdissected from freeze dried preparations of the closer muscle in walking legs of the crab Eriphia spinifrons. Shortening velocities were determined in slack(More)