[Electrophoresis of proteins of muscle fibers with rimmed vacuoles].

This is the first report on the analysis of the proteins in the single muscle fibers with rimmed vacuoles. A new method was developed to analyse single muscle fibers which had been histologically characterized in the freeze-dried sections of muscles. Muscle biopsy was performed in three patients with distal myopathy and one patient with Kearns-Sayre-like syndrome associated with rimmed vacuoles (Table 1). Ten (30 micron thick) frozen serial sections were dried according to Lowry and Passonneau, and further five consecutive sections were cut and stained with usual histochemical methods including Gomori trichrome and NADH-TR staining. Each muscle fiber in the freeze-dried sections could be identified with the corresponding one in the stained sections, and it was possible to determine whether the fiber had rimmed vacuoles or not (Fig. 2). Particular fibers were identified in the consecutive freeze-dried sections and cut out from three sections with no contamination of the interstitial tissue, and they were subjected to SDS gel electrophoresis. Resultant gel patterns showed substantial increase of 55 k dalton band, the extent of which was much more larger in that of the fiber with rimmed vacuoles than that without vacuoles (Fig. 3). This feature was common to all of the gels from four patients. A portion containing a number of muscle fibers of a freeze-dried section from each of the four patients and the two controls was subjected to two-dimensional gel electrophoresis (2-D). Of 55 k dalton proteins, three spots around the isoelectric point of alpha-actin were found to be increased (Fig. 4).(ABSTRACT TRUNCATED AT 250 WORDS)