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Paraoxonase ( PON ) 1, 2 and 3 Expression in Granulosa Cells and PON 1 Activity in Follicular Fluid of Dairy Cows
Author(s) -
Schneider A,
AbsalonMedina VA,
Esposito G,
Corrêa MN,
Butler WR
Publication year - 2013
Publication title -
reproduction in domestic animals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.546
H-Index - 66
eISSN - 1439-0531
pISSN - 0936-6768
DOI - 10.1111/rda.12198
Subject(s) - follicular fluid , paraoxonase , andrology , biology , microbiology and biotechnology , endocrinology , medicine , oocyte , oxidative stress , embryo
Contents Normal metabolic activity in ovarian follicles may result in oxidative stress and damage to oocytes. The aim of this study was to evaluate expression of the natural anti‐oxidants paraoxonase ( PON ) 1, 2 and 3 in granulosa cells and PON 1 activity in follicular fluid ( FF ) and plasma of dairy cows. For the first experiment, ovaries were collected from cows at slaughter, after which follicles were dissected and classified as oestrogen active ( EAF ) or atretic ( ATF ). Expression of PON 1, PON 2 and PON 3 m RNA was evaluated in granulosa cells, and activity of PON 1 was measured in FF . PON 1 m RNA was undetectable in granulosa cells, PON 2 m RNA expression was not different between follicle types, and PON 3 m RNA tended to be higher in EAF (p = 0.11). The activity of PON 1 in FF was higher (p = 0.01) for EAF (82.6 ± 8.0 k U / L ) than ATF (53.9 ± 6.8 k U / L ), as were high‐density lipoproteins ( HDL ), low‐density lipoproteins ( LDL ) and total cholesterol concentrations. In the second experiment, we aimed to compare plasma and FF PON 1 activity in early lactation H olstein cows (n = 15) with pre‐ovulatory EAF . Activity of PON 1 was twofold higher (p < 0.0001) in plasma (122.5 ± 11.1 k U / L ) than in FF (61.4 ± 5.2 k U / L ). Plasma concentrations were also higher (p < 0.0001) for HDL , LDL and total cholesterol when compared to FF . In conclusion, FF concentrations of PON 1, HDL , LDL and total cholesterol were higher in healthy oestrogen active bovine follicles than in atretic follicles. PON 1 was not expressed by granulosa cells indicating that high PON 1 activity in bovine FF is apparently derived by transfer from blood in association with HDL .