Mode of stimulation by injection of cyclic AMP and external acidification of the sodium efflux in barnacle muscle fibres

The Journal of Physiology
E E BittarR Schultz


1. A study has been made in single barnacle muscle fibres of the effect of micro-injected pure protein kinase inhibitor (PKI) on the response of the Na efflux to injection of cyclic AMP and external acidification. 2. (i) Injection into fibres of 1.6 x 10(-4) M-pure PKI is without effect on the resting Na efflux. (ii) Injection of 1.6 x 10(4) M-pure PKI before 0.03 M-cyclic AMP causes a marked reduction in the magnitude of the response of the Na efflux to the nucleotide. The same is true when 10(-4) M-cyclic AMP is injected after PKI. (iii) Injection of partially pure catalytic subunits causes a sustained stimulation of the ouabain-insensitive Na efflux, which is almost completely reversed by injecting PKI. (iv) Injection of 100 mM-EGTA before PKI fails to alter the lowered response of the ouabain-insensitive Na efflux to injection of 10(-4) M-cyclic AMP. (v) Ouabain (10(-4) M) when applied following the injection of 10(-4) M-cyclic AMP causes a drastic fall in the stimulated Na efflux. 3. (i) Injection of 1.6 x 10(-4) M-pure PKI before or after external acidification fails to abolish or reduce the stimulatory response to acidification. (ii) Injection of 1.6 x 10(-4) M-pure PKI before acidification practically abolishes the resp...Continue Reading


Feb 28, 1981·The Journal of Membrane Biology·D Mason-Sharp, E E Bittar
Jan 1, 1985·Comparative Biochemistry and Physiology. C, Comparative Pharmacology and Toxicology·J Nwoga, E E Bittar
Jan 1, 1984·Comparative Biochemistry and Physiology. C, Comparative Pharmacology and Toxicology·E E Bittar, J Nwoga
Jan 1, 1987·Comparative Biochemistry and Physiology. B, Comparative Biochemistry·E E Bittar, P R Girard
Dec 1, 1982·Pflügers Archiv : European journal of physiology·E E Bittar, J Nwoga

Related Concepts

Protein Kinase Inhibitors
Sodium Ion Transport
Cyclic AMP
Injection Procedure
PKIB protein, human
Egtazic Acid
Cyclic AMP-Dependent Protein Kinases

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