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Metenkephalin in Seminal Plasma of Infertile Men
Author(s) -
Fujisawa Masato,
Kanzaki Masanori,
Okada Hiroshi,
Arakawa Soichi,
Kamidono Sadao
Publication year - 1996
Publication title -
international journal of urology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 67
eISSN - 1442-2042
pISSN - 0919-8172
DOI - 10.1111/j.1442-2042.1996.tb00538.x
Subject(s) - sperm , sperm motility , oligospermia , semen , andrology , chemistry , medicine , male infertility , infertility , biology , pregnancy , genetics
Background: Enkephalin is one of the opioids, which is expressed widely in reproductive organs. However, the function of enkephalin in male reproduction is not completely understood. The effect of metenkephalin on sperm motility remains especially controversial. In this study we examined the level of metenkephalin in seminal plasma from men with normal sperm production and patients with asthenospermia, oligospermia, and azoospermia to investigate the role of metenkephalin in seminal plasma on sperm function. We also investigated the effect of metenkephalin on sperm motility in vitro. Methods: Sixty nine infertile patients (31 oligospermic, 21 asthenospermic, and 17 azoospermic) were included in this study. The level of metenkephalin in seminal plasma of these men was measured and the effect of the peptide on the motility of human sperm was examined in vitro. Seventeen men with normal seminograms were a control group. Results: The level of metenkephalin in the seminal plasma of semen from asthenospermic men was significantly lower than that from the controls ( P < 0.05). No significant correlations between the level of metenkephalin and the mean pathing or progressive velocity of sperm, or serum hormone levels were observed. In the in vitro study, which used semen from the controls, treatment of sperm with metenkephalin (50–200 pg/mL) maintained sperm motility for 4 hours. On the other hand, motility of sperm incubated without metenkephalin began to decrease at 3 hours. Metenkephalin levels of 50 pg/mL in seminal plasma is considered to be necessary for maintaining sperm motility. Conclusion: These results suggest that metenkephalin in seminal plasma is an important clue in the investigation of decreased sperm motility.