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Influence of pentachlorophenol on light emission from single barnacle muscle fibers preloaded with aequorin.

Bittar EE, Wu JR - Environ. Health Perspect. (1993)

Bottom Line: 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).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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Affiliation: Department of Physiology, University of Wisconsin, Madison 53706.

ABSTRACT
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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Influence of pentachlorophenol on light emission from single barnacle muscle fibers preloaded with aequorin.

Bittar EE, Wu JR - Environ. Health Perspect. (1993)

© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC1519876&req=5

Bottom Line: 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).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.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology, University of Wisconsin, Madison 53706.

ABSTRACT
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.

Show MeSH