BACKGROUND

Penile hypersensitivity is one of the main pathological mechanisms of premature ejaculation. However, little is known about the neurophysiological mechanism of penile peripheral nerve sensitization. Piezo Type Mechanosensitive Ion Channel Component 2 (PIEZO2), was recently identified as a mechanically sensitive channel.

OBJECTIVES

This study explored the possible neural mechanisms of PIEZO2 action in the mechanisms of premature ejaculation using molecular biology and electrophysiology approaches.

MATERIALS AND METHODS

One hundred seventy male rats and 85 female rats were recruited. The females were induced estrus by injection of estradiol benzoate and progesterone followed by surgically castrated. Subsequently, the copulatory behaviors were record by a video camera six times, once a week. The last three mating processes of 134 male rats were successfully recorded. The males were divided into three groups according to ejaculation frequency value. Immunocytochemical and molecular methods as well as whole-cell patch clamp recording were used to show the difference between premature ejaculation rats and control rats. To further clarify the involvement of PIEZO2 in premature ejaculation, we constructed a PIEZO2 knockdown model in rats by intrathecal injection of PIEZO2 antisense oligodeoxynucleotides.

RESULTS

We showed that PIEZO2 in the penis head and in the dorsal root ganglia(DRG) were significantly increased in premature ejaculation rats. Whole-cell patch clamp recording demonstrated that mechanical stimulation evoked a higher inward current density in premature ejaculation rats compared with control rats, which could be inhibited by the PIEZO2-specific antagonist, FM1-43. PIEZO2 knockdown experiments revealed that the inward current density induced by mechanical stimulation was significantly decreased in PIEZO2 knockdown rats, and that the mount frequency and ejaculation latency and frequency were significantly improved in PIEZO2 knockdown rats.

DISCUSSION AND CONCLUSION

Our data demonstrate PIEZO2 involvement in peripheral nerve sensitization, indicating that pharmacological antagonism of PIEZO2 may be a useful strategy for treating premature ejaculation.