Possible link of different slow calcium signals generated by membrane potential and hormones to differential gene expression in cultured muscle cells

• Autores: Enrique Jaimovich, Alejandra Espinosa
• Localización: Biological Research, ISSN-e 0717-6287, ISSN 0716-9760, Vol. 37, Nº. 4, 2004, págs. 625-633
• Idioma: inglés
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• Resumen

  • We studied the effect of IGF-I, insulin and testosterone on intracellular Ca2+ in cultured muscle cells. Insulin produced a fast (<1 s) and transient [Ca2+] increase lasting less than 10 s. IGF-I induced a transient [Ca2+] increase, reaching a fluorescence peak 6 s after stimulus, to return to basal values after 60 s. Testosterone induced delayed (35 s) and long lasting (100-200 s) signals, frequently associated with oscillations. IGF-I, testosterone and electrical stimulation-induced Ca2+ signals were shown to be dependent on IP3 production. All of these Ca2+ signals were blocked by inhibitors of the IP3 pathway. On the other hand, insulin-induced Ca2+ increase was dependent on ryanodine receptors and blocked by either nifedipine or ryanodine. The different intracellular Ca2+ patterns produced by electrical stimulation, testosterone, IGF-I and insulin, may help to understand the role of intracellular calcium kinetics in the regulation of gene expression by various stimuli in skeletal muscle cells.