Lactonase activity and status of paraoxonase 1 in Chinese women with polycystic ovarian syndrome

Abstract

Objective: To study the relationship between the lactonase activities and status of paraoxonase 1 (PON1) and its association with the PON1 genetic polymorphisms in women with polycystic ovarian syndrome (PCOS). Design: A case-control study. Methods: A total of 455 PCOS patients and 441 control women were included in this study. The lactonase activities and concentrations of PON1 were assayed using 5-thiobutyl butyrolactone (TBBL) and 7-O-diethylphosphoryl-3-cyano-4-methyl-7-hydroxycoumarin (DEPCyMC) respectively. A normalized lactonase activity (NLA) was estimated based on the ratio of TBBLase:DEPCyMCase activity. The PON1 genotypes, serum malondialdehyde (MDA) levels and total antioxidant capacity were analyzed. Results: The lactonase activities and levels of PON1 were higher in PCOS patients than in the control women. However, the NLA did not significantly differ between groups. The K108C/T variation of the PON1 gene showed decreased lactonase activities and levels of PON1 in a genotype-dependent manner (CCOCTOTT); the 192Q/R variation of the PON1 gene showed increased PON1 lactonase activities and NLA; and the 55L/M variation of the PON1 gene showed decreased lactonase activities and levels of PON1 but an increased NLA. A multivariable regression analysis showed that the K108C/T, 192Q/R, and 55L/M variations of the PON1 gene, serum apolipoprotein A1, and MDA levels were significant predictors of PON1 lactonase activity, PON1 level, and NLA. Conclusions: The serum lactonase activities and concentrations of PON1 are increased in PCOS patients. The increased oxidative stress and the K108C/T, 192Q/R, and 55L/M genetic polymorphisms of PON1 may be associated with these changes.

Lactonase Activity, Status, and Genetic Variations of Paraoxonase 1 in Women with Gestational Diabetes Mellitus

“…Stress Markers. The lactonase activity and levels of PON1 were determined using 5-thiobutyl butyrolactone (TBBL) and 7-O-diethylphosphoryl-3-cyano-4-methyl-7-hydroxycoumarin (DEPCyMC) as a substrate, respectively, based on the measurement described in our earlier study [16]. A normalized lactonase activity ðNLAÞ = TBBL activity ðU/mLÞ × 1000/ DEPCyMC activity (mU/mL) [14,16].…”

“…Some PON1 genetic variations have been reported to influence the enzyme concentration and specific activity of PON1 [10,15]. The −108C/T variant of the PON1 gene influences PON1 expression and the 192Q/R polymorphism affects PON1 activities [9,10,16]. The PON1 R isoform hydrolyzes lipid peroxides in vitro less efficiently than does the Q isoform [9].…”

Oxidative stress status in Chinese women with different clinical phenotypes of polycystic ovary syndrome

“…In addition, our recent study demonstrated that E 2 levels correlated positively with intrinsic HDL oxidation levels in patients with PCOS . E 2 or oestrogen may increase of HDL binding and oxidized lipid transport by elevating apoA1 levels, which may contribute to increase circulating TOS and OSI because HDL is the major carrier of lipid hydroperoxides …”

“…Our previous studies demonstrated that patients with HA have higher serum MDA levels and more severe impairment of high‐density lipoprotein (HDL) antioxidant activities than those without HA . In addition, the lactonase activities and levels of PON1 were higher, and HDL‐associated platelet‐activating factor acetylhydrolase (PAF‐AH) activities were lower in patients with PCOS than in controls . Furthermore, the PAF‐AH G994T gene mutation and the PON1 Q192R gene variation are risk factors for PCOS .…”

Effect of the R92H and A379V genotypes of platelet-activating factor acetylhydrolase on its enzyme activity, oxidative stress and metabolic profile in Chinese women with polycystic ovary syndrome

“…Oligo- or anovulation (OA) was assessed as oligomenorrhea (i.e., fewer than eight cycles per year). Biochemical or clinical hyperandrogenism (HA) was assessed by total testosterone (TT) levels above the 95th percentile of the levels (2.60 nmol/l) detected in a group of normal menstruating women with normal cycles, hirsutism with a modified Ferriman–Gallwey (F-G) score of more than 6 and/or clinical presence of obvious acne [4, 27, 28]. Polycystic ovaries (PCOs) were confirmed if there were 12 or more follicles in each ovary measuring 2–9 mm in diameter and/or increased ovarian volume (>10 mL) by ultrasonic examination.…”