Bioenergetics and cell communication; cell uncoupling seen as a protective mechanism in cardiac muscle.
Differences in rate of ATP resynthesis between apposing heart cells were created by dialysing 2-4-dinitrophenol (0.01-0.05 mM) into just one cell of isolated heart cell pairs. When 0.01 mM of dinitrophenol was used the junctional conductance (gj) remained unchanged for at least 8 min if cell 1 (normal) was pulsed at low rate (0.04 Hz). The increment in rate of pulsing to 4 Hz caused a fast decrease (13%) of gj within 30 sec. This change in gj was spontaneously reversed. With 0.05 mM of dinitrophenol cell uncoupling was produced if cell 1 (normal) was stimulated at 4 Hz for 25-30 sec. Despite the suppression of electrical coupling (which was not reversed within 8 min.) no contracture or signs of deterioration of the experimental conditions were found. Cell uncoupling can be seen as a protective mechanism providing opportunity to energy-depleted cells to re-establish their ATP stores.
De Mello
W C
WC
Department of Pharmacology, School of Medicine, Medical Sciences Campus, San Juan, P.R. 00936-5067.
D019297:2,4-Dinitrophenol; D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000818:Animals; D002450:Cell Communication / Q000502:physiology; D004140:Dinitrophenols / Q000494:pharmacology; D004553:Electric Conductivity; D004558:Electric Stimulation; D004734:Energy Metabolism; D006321:Heart / Q000187:drug effects; D066298:In Vitro Techniques; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D010085:Oxidative Phosphorylation / Q000187:drug effects; D051381:Rats; D014475:Uncoupling Agents / Q000494:pharmacology
D004140:Dinitrophenols; D014475:Uncoupling Agents; D000255:Adenosine Triphosphate; D019297:2,4-Dinitrophenol