Paraoxonase 1 Activity and Lipid Concentrations in Serum and Seminal Plasma of Simmental Bulls

Cilj istraživanja bio je utvrditi aktivnost PON1 i koncentracije lipida u serumu i sjemenoj plazmi simentalskih bikova ovisno o sezoni i dobi životinja. Uzorci krvi i sjemena bikova uzimani su u ljeto i zimu. U serumu je određena aktivnost PON1, koncentracija ukupnog kolesterola, kolesterola vezanog na lipoproteine velike gustoće (HDL-C) te triacilglicerola i slobodnih masnih kiselina, a u sjemenoj plazmi aktivnost PON1 i koncentracije kolesterola i triacilglicerola. Aktivnost PON1 i vrijednost omjera PON1/HDL-C u serumu bikova s genomskim testom bile su značajno veće u oba godišnja doba u odnosu na progeno testirane bikove. Koncentracija slobodnih masnih kiselina u uzorcima obje skupine bikova bila je značajno veća u ljeto u odnosu na vrijednosti dobivene u zimu. Koncentracije kolesterola i triacilglicerola u sjemenoj plazmi obje skupine bikova bile su značajno veće u zimskom periodu u odnosu na ljeto. U ljetnim je uzorcima sjemene plazme progeno testiranih bikova koncentracija kolesterola bila je značajno veća u odnosu na vrijednosti dobivene u sjemenoj plazmi bikova s genomskim testom. Rezultati istraživanja potvrđuju da je serumska aktivnost PON1 ovisna o dobi dok koncentracija NEFA ukazuje na povećanu mobilizaciju masti zbog manjeg uzimanja hrane usljed visokih ljetnih temperatura.The aim of this study was to investigate PON1 activity and lipid concentrations in serum and seminal plasma of Simmental bulls according to seasonality and age. Blood samples and bovine semen were obtained in summer and in winter. Serum PON1 activity, concentrations of total cholesterol, high density lipoprotein cholesterol (HDL-C), triacylglycerols and nonesterified fatty acids (NEFA) were determined; whereas seminal plasma PON1 activity and concentrations of total cholesterol and triacylglycerols were analyzed. Activity of PON1 and PON1/HDL-C ratio in serum of bulls with genomic test were significantly higher in both seasons compared with progeny tested bulls. The NEFA concentrations recorded in serum samples of both group collected in summer was significantly higher compared with that in winter. Concentrations of cholesterol and triacylglycerols in seminal plasma were significantly higher in winter samples compared with summer samples in both groups. In summer samples, seminal plasma concentrations of cholesterol and triacylglycerols of bull with progeny test were significantly higher compared with that in bulls with genomic test. In conclusion, we confirmed the relation between PON1 activity and the bulls age. The higher summer NEFA concentrations show that bulls are less prone to eating due to high temperatures during summer, and therefore use their body fat reserves