Serotonergic signals enhanced hamster sperm hyperactivation

• Main Authors: Chiyori SAKAMOTO (Author), Masakatsu FUJINOKI (Author), Masafumi KITAZAWA (Author), Satoshi OBAYASHI (Author)
• Format: Book
• Published: The Society for Reproduction and Development, 2021-05-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 0916-8818; 1348-4400; 10.1262/jrd.2020-108
• Keywords: 5-hydroxytryptamine (5-ht); 5-ht2 receptor; 5-ht4 receptor; hyperactivation; sperm; Reproduction; QH471-489; Internal medicine; RC31-1245
• Source: The Journal of Reproduction and Development, Vol 67, Iss 4, Pp 241-250 (2021)

In the present study, we investigated the regulatory mechanisms underlying sperm hyperactivation enhanced by 5-hydroxytryptamine (5-HT) in hamsters. First, we examined the types of 5-HT receptors that regulate hyperactivation. Hyperactivation was significantly enhanced by 5-HT2A and 5-HT4 receptor agonists. Moreover, the results of the motility assay revealed that 5-HT2A, 5-HT3, and 5-HT4 receptor agonists significantly decreased the velocity and/or amplitude of sperm. Under 5-HT2 receptor stimulation, hyperactivation was associated with phospholipase C (PLC), inositol 1,4,5-trisphosphate (IP3) receptor, soluble adenylate cyclase (sAC), and protein kinase A (PKA). In contrast, under 5-HT4 receptor stimulation, hyperactivation was associated with transmembrane adenylate cyclase (tmAC), sAC, PKA, and CatSper channels. Accordingly, under the condition that sperm are hyperactivated, 5-HT likely stimulates PLC/IP3 receptor signals via the 5-HT2A receptor and tmAC/PKA/CatSper channel signals via the 5-HT4 receptor. After sAC and PKA are activated by these stimulations, sperm hyperactivation is enhanced.