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Influence of pentachlorophenol on light emission from single barnacle muscle fibers preloaded with aequorin.
Experiments show that the resting ouabain-insensitive sodium efflux in giant fibers from the barnacle Balanus nubilus is stimulated by external application of pentachlorophenol (PCP). This work has now been extended to include a study of muscle fibers preloaded with the Ca2+ indicator aequorin to de...
Autores principales: | , |
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Formato: | Texto |
Lenguaje: | English |
Publicado: |
1993
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1519876/ https://www.ncbi.nlm.nih.gov/pubmed/8143595 |
Sumario: | Experiments show that the resting ouabain-insensitive sodium efflux in giant fibers from the barnacle Balanus nubilus is stimulated by external application of pentachlorophenol (PCP). This work has now been extended to include a study of muscle fibers preloaded with the Ca2+ indicator aequorin to determine whether PCP is able to increase light emission; and whether its potency depends on the number of chlorine atoms and external pH. The results obtained are as follows: 1) PCP causes a dose-dependent, multiphasic rise in light emission; the threshold concentration in fibers not poisoned with ouabain was in the low micromolar range. 2) The efficacy of PCP is considerably greater than that of less-chlorinated phenols and phenol. 3) The response to PCP is a sigmoidal function of external pH both in unpoisoned and ouabain-poisoned fibers. Reducing external pH potentiates its efficacy. 4) The response to PCP depends on the external Ca2+ concentration, and the requirement for Ca2+ is usually absolute. |
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