Distinct lethal arrhythmias susceptibility is associated with sex-related difference in myocardial connexin-43 expression.
OBJECTIVE
To elucidate gender-related differences in occurrence of sudden cardiac death the myocardial connexin-43 (Cx43) and the susceptibility of male and female rat hearts to ventricular fibrillation (VF) were investigated.


RESULTS
Ventricular tissues taken from male and female normotensive Wistar and spontaneously hypertensive (SHR) rats were processed for immuno-fluorescence and immuno-blotting of Cx43. Susceptibility to ventricular fibrillation was examined in isolated heart preparation using either electrical stimulation or low K+ perfusion. Results showed that VF susceptibility of male either normotensive or hypertensive rats was significantly increased comparing to female counterparts. In correlation, ventricular expression of Cx43 was markedly lower in males of both normotensive and hypertensive rats comparing to females. SHR in addition exhibited abnormal myocardial Cx43 distribution due to structural remodelling.


CONCLUSIONS
Findings indicate that higher level of myocardial Cx43 expression is linked with lower lethal arrhythmia susceptibility and vice versa. It appears that Cx43 can be involved in sex-related differences in incidence of life-threatening arrhythmias.
Knezl
Vladimir
V
Institute of Experimental Pharmacology, Slovak Academy of Sciences, Bratislava, Slovakia. exfaknem@savba.sk
Bacova
Barbora
B
Kolenova
Lucia
L
Mitasikova
Marcela
M
Weismann
Peter
P
Drimal
Jan
J
Tribulova
Narcis
N
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000235:genetics* / Q000503:physiopathology; D018031:Connexin 43 / Q000096:biosynthesis* / Q000235:genetics; D017630:Connexins / Q000378:metabolism; D004562:Electrocardiography; D005260:Female; D007150:Immunohistochemistry; D008297:Male; D008856:Microscopy, Fluorescence; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR; D017208:Rats, Wistar; D012727:Sex Characteristics
D018031:Connexin 43; D017630:Connexins