Sex differences to myocardial ischemia and -adrenergic receptor blockade in conscious rats

Lujan HL, DiCarlo SE. Sex differences to myocardial ischemia and -adrenergic receptor blockade in conscious rats. Am J Physiol Heart Circ Physiol 294: H1523–H1529, 2008. First published Febru-ary 8, 2008; doi:10.1152/ajpheart.01241.2007.—We recently docu-mented sex differences in the susceptibility to reperfusion-induced sustained ventricular tachycardia and -adrenergic receptor blockade in conscious rats. However, the effect of sex on ischemia-induced ventricular arrhythmias and -adrenergic receptor blockade is under-investigated. Therefore, we tested the hypothesis that gonadal hor-mones influence the ventricular arrhythmia threshold (VAT) induced by coronary artery occlusion as well as the response to -adrenergic receptor blockade. The VAT was defined as the time from coronary occlusion to sustained ventricular tachycardia resulting in a reduction in arterial pressure. Male and female intact and gonadectomized (GnX) rats were instrumented with a radiotelemetry device for re