Determination of myoglobin-diffusivity in intact skeletal muscle fibers. An improved microscope-photometrical approach.

Abstract

In concepts of oxygen transport to muscle tissue an important contribution of myoglobin-facilitated oxygen diffusion to the intracellular oxygen transport is frequently assumed (Wittenberg and Wittenberg, 1990). However, there is lack of direct evidence for a corresponding high diffusivity of myoglobin in intact muscle cells. Jürgens et al. (1990) were the first to present a method to measure the intracellular diffusion coefficient of myoglobin in mammalian muscle fibers. It is based on transmission spectroscopy of dissected and superfused rat diaphragms. In geometrically defined microscopic areas of such samples, photooxidation of oxymyoglobin is performed by short UV pulses. The observed absorbance change at 420 nm, which is subsequently recorded with a computer equipped microscope photometer (Fig.1), is the consequence of the translational myoglobin diffusion along the fiber axes. Metmyoglobin diffuses out of the photometric field while oxymyoglobin enters it simultaneously. KeywordsIrradiate FieldIntracellular OxygenFrog Muscle FiberFrog Skeletal Muscle FiberIntact Muscle CellThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.