Ehrlich cell plasma membrane redox system is modulated through signal transduction pathways involving cGMP and Ca2+ as second messengers.
Ehrlich cell plasma membrane ferricyanide reductase activity increased in the presence of mastoparan, a generic activator of G proteins, using either whole cells or isolated plasma membrane-fractions. Agents that increase intracellular cAMP also increased the rate of ferricyanide reduction by Ehrlich cells. For the first time, evidence is shown on a modulation of plasma membrane redox system by cGMP. In fact, permeant analogs of cGMP, dibutyryl cGMP, and 8-bromo-cGMP increased the rate of ferricyanide reduction by the Ehrlich cell plasma membrane redox system. Furthermore, specific inhibition of cGMP-phosphodiesterases by dipyridamole was also accompanied by an enhancement in the rate of ferricyanide reduction. On the other hand, treatments expected to increase cytoplasmic Ca2+ concentrations were accompanied by a remarkable stimulation of the reductase activity. Taking all these data together, it seems that the Ehrlich cell plasma membrane redox system is under a multiple and complex regulation by different signal transduction pathways involving G proteins, cyclic nucleotides, and Ca2+ ions.
del Castillo-Olivares
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A
Laboratorio de Bioquímica y Biología Molecular, Universidad de Málaga, Spain.
Esteban del Valle
A
A
Márquez
J
J
Núñez de Castro
I
I
Medina
M A
MA
D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism*; D003995:Dibutyryl Cyclic GMP / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D007700:Kinetics; D051379:Mice; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D009355:Neomycin / Q000494:pharmacology; D010084:Oxidation-Reduction; D015290:Second Messenger Systems; D015398:Signal Transduction; D013110:Sphingosine / Q000494:pharmacology; D019284:Thapsigargin / Q000494:pharmacology
D004791:Enzyme Inhibitors; D003995:Dibutyryl Cyclic GMP; D000001:Calcimycin; D003994:Bucladesine; D019284:Thapsigargin; D009247:NADH, NADPH Oxidoreductases; C014227:ferricyanide reductase; D000252:Calcium-Transporting ATPases; D006152:Cyclic GMP; D009355:Neomycin; D013110:Sphingosine; D002118:Calcium