| Sažetak | Cilj istraživanja bio je utvrditi utjecaj pasmine i hibrida nerasta na pokazatelje
antioksidacijske zaštite spermija i sjemene plazme te biokemijske pokazatelje u sjemenoj
plazmi. Također, cilj je bio istražiti antioksidacijske pokazatelje u različitim frakcijama
spermija, razdvojenim u otopini jodiksanola. Uzorci sjemena 27 rasplodnih nerasta različitih
pasmina (švedski landras, njemački landras, veliki jorkšir, pietren) i PIC-hibrid, starosti od 1,5
do 3 godine dobiveni su ručnom fiksacijom penisa, jednokratno u jesenskom razdoblju. U
sjemenoj plazmi određena je koncentracija ukupnog antioksidativnog statusa (TAS), aktivnost
superoksid dismutaze (SOD) i glutation peroksidaze (GSH-Px), a u ispranim spermijima te u
spermijima triju frakcija određena je i koncentracija bakar-cink superoksid dismutaze te
manganska superoksid dismutaza. Najbolja sveukupna antioksidativna zaštita u sjemenoj
plazmi utvrđena je u PIC-hibrida, a najmanja u pietrena, dok je sveukupna antioksidativna
zaštita u ispranim spermijima bila najmanja u PIC-hibrida a najveća u švedskog landrasa. Iz
dobivenih rezultata moglo bi se zaključiti da postoje razlike u antioksidativnoj zaštiti sjemene
plazme i spermija u istraženim pasminama nerasta i PIC-hibrida. U PIC-hibrida smanjena
antioksidativna zaštita spermija kompenzirana je većom antioksidativnom zaštitom sjemene
plazme. Koncentracija TAS-a te aktivnost SOD-a i GSH-Px-a bila je značajno veća u
patoloških oblika spermija u odnosu na spermije velike i vrlo male gibljivosti. Najmanje
vrijednosti TAS-a te SOD-a i GSH-PX-a utvrđene su u spermijima vrlo male gibljivosti u
usporedbi s preostalim frakcijama spermija. U spermijima velike gibljivosti dobivene
vrijednosti istraživanih pokazatelja bile su značajno veće od onih u spermijima vrlo male
gibljivosti, ali značajno manje od onih u patološkim oblicima spermija. Dobiveni rezultati
ukazuju na smanjenu antioksidacijsku zaštitu spermija vrlo male gibljivosti u odnosu na
spermije velike gibljivosti. Značajno veće vrijednosti TAS-a te SOD-a i GSH-Px-a u
patoloških oblika spermija mogu ukazivati na pojačan antioksidativni obrambeni odgovor
zbog pojačanog stvaranja ROS-a u toj frakciji spermija. Nerasti iz skupine PIC-hibrida imali
su značajno veću koncentraciju ukupnog kolesterola, LDL-kolesterola i triacilglicerola u
sjemenoj plazmi. U odnosu na PIC-hibride nerasti pasmine njemački landras imali su
značajno manju koncentraciju navedenih lipida, dok su nerasti pasmine pietren imali značajno
manju koncentraciju triacilglicerola i ukupnog kolesterola. Određivanje biokemijskih
pokazatelja u sjemenoj plazmi, napose masnih tvari i antioksidativnih pokazatelja, omogućuje
bolju procjenu kakvoće sjemena u svrhu uspješnije pohrane i čuvanja sjemena. |
| Sažetak (engleski) | The quality of boar semen may fluctuate significantly due to environmental and
endogenous influences (age, season, climate, genetics, nutrition, breed etc.). Knowledge of
the physiological features of the sperm and seminal plasma and the impact of the breed, lines
and individual features of the boar, are a prerequisite for the successful improvement of
reproductive efficiency and the heredity of the best genetic traits of semen. Oxidative stress is
the primary cause of fertility disorders in mammals, but semen has an antioxidative system
which helps it to neutralize the effect of the production of excessive reactive oxygen
compounds. Sperm is particularly susceptible to oxidative damage due to the excessive
production of reactive oxygen compunds, and because of the large proportion of unsaturated
fatty acids in the plasma membrane and a relatively low concentration of antioxidant enzymes
in the cytoplasm. Porcine semen is composed of heterogeneous subpopulations of sperm that
are distinguished by their functional and structural features, and the share of each
subpopulation is associated with the ability of fertilization and the storing of semen. The aim
of the study was to determine the influence of boar breeds and hybrids on semen quality, the
parameters of antioxidant protection of both spermatozoa and seminal plasma of boars and
biochemical parameters in their seminal plasma. Also, the aim was to investigate antioxidant
parameters in different sperm fractions, separated in iodixanol density gradient solution.
Semen samples of 27 boars (belonging to either breeds of Swedish Landrace, German
Landrace, Large White, Pietrain or PIC-hybrid) aged between 1.5 and 3 years were collected
by gloved-hand technique, once, in autumn season. After the evaluation of semen quality, the
seminal plasma was separated from the sperm by centrifugation of semen (1,000 x g/15 min).
Part of the native semen was centrifuged in a discontinuous iodixanol density gradient
solution for 20 min at 1500 x g at 20°C. After the centrifugation, three sperm fractions were
obtained: sperm with progressive mobility greater than 90%, sperm with progressive mobility
less than 20% and abnormal sperm. In the seminal plasma the biochemical parameters as well
as the concentration of total antioxidant status (TAS), and the activities of total superoxide
dismutase (TSOD) and glutathione peroxidase (GSH-Px) were determined. Besides of the
aforementioned parameters, in the washed sperm and and in three fractions of sperm the
activities of copper-zinc superoxide dismutase and manganese superoxide dismutase were
determined too. The best overall antioxidant protection in seminal plasma was determined in
the PIC-hybrids, and the lowest in the Pietrain breed, while the overall antioxidant protection
in the washed sperm was the lowest in the PIC-hybrids and the highest in Swedish Landrace.
From the obtained results, it can be concluded that there are differences in the antioxidative
protection of seminal plasma and sperm in the above mentioned boar breeds and PIC-hybrids.
Diminished antioxidant protection of sperm in the PIC-hybrids could be compensated by a
higher antioxidant protection of seminal plasma.
In the abnormal sperm fraction, the concentration of TAS, and the activities of TSOD
and GSH-Px were significantly higher (P<0.001) than those in the fractions of high and very
low mobility of sperm. The lowest values of TAS and TSOD and GSH-PX were obtained in
sperm with very low mobility (P<0.001). The results indicated a decrease in antioxidative
protection of sperm with very low mobility in relation to the sperm with high mobility. The
highest levels of TAS, SOD and GSH-Px found in abnormal sperm could indicate the
enhanced antioxidative defence due to excessive production of reactive oxygen species in that
sperm fraction. The sperm fraction of high mobility and normal morphology could be applied
in the assisted reproduction, but systematic study of the antioxidant parameters, as well as the
evaluation of their values in the above mentioned sperm fractions may contribute to a better
understanding of fertilizing properties and causes of infertility.
PIC-hybrid boars had a significantly higher concentrations of total cholesterol, LDLcholesterol, triacylglycerols in seminal plasma, and German Landrace boars had a
significantly lower concentration of the all above mentioned lipids as compared to PIChybrids. The Pietrain boars had a significantly lower concentration of triacylglycerols and
total cholesterol in compared to the PIC-hybrids. The determination of biochemical
parameters, particularly lipid substances and antioxidant parameters in boar seminal plasma,
contributes to a better assessment of boar semen quality and a higher concentration of the
above mentioned fatty substances enables successful storage and preservation of the frozen
semen. |
