the effect of androgen deprivation on the expression of connexin-43 mrna in the heart

Connexin-43 (cx-43) plays axial roles in the propagation of action potentials and contractile coupling in heart. down-regulation of cx-43 in heart is associated with arrhythmia, dilated cardiomyopathy and heart failure. to date, no studies have examined the effects of androgen deprivation therapy (adt)-induced hypogonadism on the expression of cx-43 in heart. this study investigated the effects of testosterone deprivation and its replacement with testosterone on the expression of cx-43 mrna and muscle-specific mirnas mir-206 and mir-1, as two potential regulators of the cx-43 protein expression in the ventricular tissue. accordingly, 21 male wistar rats were divided into three groups: ι) normal control, п) orx-s: castrated rats serving as animal models for adt and receiving the sesame oil as a solvent of testosterone enanthate for 10 weeks, and ш) orx-t: these animals were castrated, receiving testosterone enanthate (25 mg/kg) for 10 weeks. the relative expression of cx-43 mrna, mir-206 and mir-1 was determined by qrt-pcr. cx-43 mrna was found to be decreased in the orx-s group. the cx-43 mrna was up-regulated after the administration of testosterone enanthate. there were no significant changes in mir-206 and mir-1 levels in the orx-s and orx-t groups when compared to the controls. our results indicated that testosterone should be regarded as an important factor in the regulation of the cx-43 mrna expression in heart, and testosterone deprivation may down-regulate the cx-43 mrna expression; however, it doesn’t alter mir-1 and mir-206 levels. these results suggest that adt-induced hypogonadism may put males at risk for cardiac dysfunctions.