As to the involved mechanisms, it can be speculated that PDRN, as previously shown for an experimental model of varicocele (Minutoli et al., 2011), activates the A2A receptors of sperm cells and stimulates adenylate cyclase activity (Fraser and Duncan, 1993), acting in vivo as a regulator of sperm function even during Cd challenge. This evidence concerns the gene ADCY1 and varicocele.