Naslov
Does melatonin act as an antioxidant in human semen ?

Autori
Gavella, Mirjana ; Lipovac, Vaskresnija

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
International Journal of Andrology, suppl. 1 / Frick, Joseph - : Wiley-Blackwell, 1997, 17-17

Skup
VI. International Congress of Andrology

Mjesto i datum
Salzburg, Austrija, 25.05.1997. - 29.05.1997

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
melatonin; antioxidant; lipid peroxidation; spermatozoa; semen
(melatonin; antioxidant; lipid peroxidation; human spermatozoa; semen)

Sažetak
Recent in vivo and in vitro experiments show that pineal hormone melatonin provides defence against oxidative damage, especially lipid peroxidation in retina, brain and liver cells. Sincel lipid peroxidation of sperm membrane is considered to be the kay mechanism of damage to spermatozoa, we aimed to examine the potential protective role of melatonin on human spermatozoa. The effect of melatonin was compared to vitamin E, found to be effective in the suppression of iron-catalyzed lipid peroxidation in sperm membrane. To investigate the ability of melatonin (M) to counteract lipid peroxidation (LPO) in human spermatozoa we determined its capacity to suppress the formation of malondialdehyde (MDA) in the presence of promoter system.Washed spermatozoa were provided by 30 unselected infertile men. MDA formation was achieved by incubation 20 x 10 6 cells/ml with or without melatonin or Trolox (a soluble vitamin E analogue) in Ca 2+, Mg 2+-free Hanks buffer containinf Fe 2+ /ascorbate (0.04/0.2 mM) and incubated at 37 0C for 1 hour.Generation of MDA was assessed using the thiobarbituric acid method. Spermatozoa incubated with melatonin (2-6 mM( exhibited a concentration-dependent decrease of MDA generated from hydroperoxide of the sperm plasma membrane, similar to the suppressive effect of Tro0lox (0.1-0.2 mM). Addition of 6 mM M significantly reduced the degree of LPO in unselected donors )mean + SE in control samples = 26.4+2.99 nmol MDA/108 spermatozoa vs 6.54+1.07 nmol MDA/108 sperms in melatonin-treated samples; n=16; p 0.0005). The obtained data of in vitro experiments show that melatonin is 40-fold less efficient than Trolox in achieving the 50%reduction in LPO (4mMvs 0.1 mM). Since concentration of melatonin in human semen is found at nanomolar range, its antioxidative role is probably of minor importance.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

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