Signal transduction pathways in guinea pig sperm

Trifluoperazine (TFP), the antagonist of calmodulin (CaM). significantly stimulated the capacitation and acrosome reaction of guinea pig spermatozoa at the concentration of 10-100μmol/L, independent of the external Ca2+. Forskolin, dbcAMP and caffeine evidently promoted the occurrence of acrosome reaction of spermatozoa at early capacitation stage (5 h) in nonsynchronous system but not in synchronous system. If the spermatozoa were capacitated for 15 h in synchronous system, the above three drugs significantly stimulated acrosome reaction in a Ca2+-independent manner. Protein kinase C activators, i.e. phorbol 12-myristate 13-acetate (PMA) and phorbol 12,13-dibutyrate (PDB) did not influence the occurrence of acrosome reaction of spermatozoa at early capacitation stage, but significantly increased the acrosome reaction rate in capacitated spermatozoa in a Ca2+-independent manner. In contrast. PKC inhibitor staurosporine significantly inhibited the occurrence of acrosome reaction.     

豚鼠精子信号通路的研究

钙调素(CaM)拮抗剂三氟拉嗪(TFP)在10~100 μmol/L浓度范围内对豚鼠精子获能和顶体反应具有极显著的促进作用,且不依赖于外源Ca²⁺的存在.Forskolin,dbcAMP和咖啡因对非同步培养系统获能早期豚鼠精子的顶体反应有显著的促进作用,但对同步培养系统获能早期精子的顶体反应无显著影响.若在同步培养系统获能培养较长时间(15h)使精子获能,则这3种药物对顶体反应均具有显著的促进作用,且不依赖外源Ca²⁺的存在.蛋白激酶C(PKC)激活剂PMA和PDB对获能前期豚鼠精子的顶体反应无显著影响,但对获能精子的顶体反应有显著的促进作用,且这种促进作用也不依赖于外源Ca²⁺的存在.相反,PKC抑制剂stau-rosporine对顶体反应有显著的抑制作用.