Immediate-early gene induction by repetitive mechanical but not electrical activity in adult rat cardiomyocytes.
Mechanical factors are thought to play an important role in the induction of myocardial hypertrophy. Yet, it is not known whether active contraction induces genes that probably represent initial steps in the hypertrophic response in the adult myocardium--and if so, whether the mechanical or the electrical component of the twitch governs this response. We therefore investigated whether electrical stimulation of contraction was able to induce the immediate-early genes (IEGs) egr-1 and c-fos in adult rat cardiomyocytes. Cyclical contraction led to an increase in egr-1 and c-fos mRNA levels within 30 min. Full inhibition of contraction during electrostimulation by the Ca(2+)-desensitizer 2,3-butanedione monoxime (BDM) totally blocked this IEG-response without altering membrane potential. These data suggest that in adult myocardium, the mechanical rather than the electrical activity is responsible for the IEG-response during active twitch.
Kubisch
C
C
Medical Policlinic, University of Bonn, Germany.
Wollnik
B
B
Maass
A
A
Meyer
R
R
Vetter
H
H
Neyses
L
L
D000818:Animals; D000831:Animals, Newborn; D004268:DNA-Binding Proteins / Q000235:genetics; D003931:Diacetyl / Q000031:analogs & derivatives / Q000494:pharmacology; D051766:Early Growth Response Protein 1; D004558:Electric Stimulation; D005786:Gene Expression Regulation; D017781:Genes, Immediate-Early; D016762:Genes, fos; D017874:Immediate-Early Proteins; D007700:Kinetics; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology*; D009206:Myocardium / Q000378:metabolism*; D011189:Potassium Chloride / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011921:Rats, Inbred WKY; D014157:Transcription Factors / Q000235:genetics; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D051766:Early Growth Response Protein 1; C486110:Egr1 protein, rat; D017874:Immediate-Early Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; C004717:diacetylmonoxime; D011189:Potassium Chloride; D003931:Diacetyl