- 作者：Nerea Subirá ; n ; Ph.D.a ; b ; nerea.subiran@ehu.es ; Luz Candenas ; Ph.D.b ; Francisco M. Pinto ; Ph.D.b ; Antonio Cejudo-Roman ; J.D.b ; Ekaitz Agirregoitia ; Ph.D.a ; Jon Irazusta ; Ph.D.a
- 关键词：Opioid peptides ; sperm ; human ; autocrine ; male fertility
- 刊名：Fertility and Sterility
- 出版年：2012
- 出版时间：September, 2012
- 年：2012
- 卷：98
- 期：3
- 页码：617-625.e3
- 全文大小：705 K
Objective
To verify the presence of protein precursor pro-enkephalin (PENK) and met-enkephalin in human spermatozoa and to characterize the effects of exogenous and endogenous enkephalins on sperm motility.Design
We carried out expression assays for met-enkephalin and its protein precursor PENK by reverse transcription-polymerase chain reaction (RT-PCR), Western blot, and immunofluorescence techniques in sperm cells and motility analysis after incubation of semen samples with met-enkephlin enzyme inhibitors and the opioid receptor antagonist naloxone. Met-enkephalin secretion was analyzed by flow cytometry.
Setting
Assisted reproduction unit and academic research laboratory.
Patient(s)
Semen from 50 normozoospermic healthy human donors.
Intervention(s)
Spermatozoa isolated from semen on discontinuous Percoll gradient (40 % -80 % ) followed by a swim-up was used for all techniques.
Main Outcome Measure(s)
Immunoblotting blots, indirect immunofluorescence antibody assays, RT-PCR blots, flow cytometry plots, and percentage of motile sperm.
Result(s)
We found by RT-PCR and immunofluorescence that met-enkephalin and its protein precursor PENK are present in the head of human sperm cells. Endogenous met-enkephalin increased sperm motility, whereas the addition of exogenous met-enkephalin had a biphasic effect on motility, likely due to the activation of distinct receptor subtypes.
Conclusion(s)
We provide evidence for a new role of met-enkephalin as an endogenous mediator of sperm motility. This autocrine regulation of sperm function by the opioid system represents a new mechanism of regulation of male factor fertility and could be useful as an emerging target for male contraception.