ISSN:
0021-9541
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
Satellite cells, isolated from marcaine-damaged rat skeletal muscle, differentiate in culture to form contracting, cross-striated myotubes. Addition of 20 μM hemin (ferriprotoporphyrin IX chloride) to the culture medium resulted in increases in the number, size, and alignment of myotubes; in the number of myotubes that exhibited cross-striations; and in the strength and frequency of myotube contractions. Hemin increased satellite cell fusion by 27%, but decreased cell proliferative rate by 30%. Hemin increased the specific activity of creatine kinase (CK), a sensitive indicator of muscle differentiation, by 157%. Separation of CK isoenzymes by agarose gel electrophoresis showed that hemin increased only the muscle-specific CK isoenzymes (MM-CK and MB-CK). Thus, hemin seems to duplicate some of the effects of innervation on cultured myotubes by increasing contraction frequency and strength, appearance of cross-striations, and muscle-specific isoenzymes. In contrast, 3-amino-1,2,4-triazole, an inhibitor of heme biosynthesis, decreased the number of cross-striated myotubes, the strength and frequency of myotube contractions, and CK activity. These inhibitory effects were reversed by hemin. Collectively, these results demonstrate a physiologically significant role for heme in myotube maturation.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1041410318
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