17α ethinylestradiol

To investigate the effect of sex hormones on EL-mediated lipoprotein metabolism, male Tg rabbits along with non-Tg littermates were undergone a bilateral orchiectomy whereas female Tg rabbits and littermates were undergone a bilateral ovariectomy [19 (link)]. All castrated rabbits were further fed a cholesterol-rich diet containing 0.3% cholesterol and 3% soybean oil for 16 weeks and then their plasma lipids and aortic lesions of atherosclerosis were compared. Because only male Tg rabbits showed protection against diet-induced hypercholesterolemia (see below), we envisioned that estrogen may suppress the functions of EL in male rabbits. To investigate this issue, male Tg rabbits and non-Tg littermates at 4 months of age were intramuscularly injected with 17α-ethinyl estradiol (Sigma-Aldrich, St. Louis; USA) at a dose of 100 μg/kg/day for 10 days [19 (link)]. After estrogen injection or ovariectomy, blood was collected from fasted rabbits for plasma lipid analysis as described above. Plasma levels of testosterone and estradiol were measured using Electro chemiluminescence immunoassay (ECLIA) (SRL, Inc. Tokyo, Japan). Plasma EL levels were measured using an ELISA kit as described previously [27 (link)].

Cypermethrin (Lot# BCCB1117), Diethyl phthalate (Lot #BCBZ8989), Vinclozolin (Lot #BCBZ5052), 17α-ethinyl estradiol (Lot #WXBC9894V), Perfluorooctanesulfonic acid (#0000091932) and Atrazine (Lot# BCBZ3835) were obtained from SIGMA-ALDRICH INC. P.O. (St. Louis, MO, USA). Unless otherwise stated, all compounds were purchased from Sigma-Aldrich. All solutions used for in vivo infusions were prepared using nonpyrogenic saline (0.9% NaCl; Baxter Healthcare Ltd., Thetford, Norfolk, UK).

All chemicals were purchased from commercial suppliers. For the synthesis of the nanocatalysts, tetraethyl orthosilicate (TEOS, 98%), polyethyleneimine (PEI, branched, average Mw 25 kDa), polyacrylic acid (PAA, average Mw 2 kDa), triblock copolymer Pluronic P123 (PEO20-PPO70-PEO20), iron(III) chloride hexahydrate (FeCl₃·6H₂O, 97%), hydrochloric acid (HCl, 37%), cyclohexane (C₆H₁₂, 99.8%), Igepal CO-520 (polyoxyethylene (5) nonylphenylether, branched), isooctane (C₈H₁₈, ≥99%) and isopropanol (C₃H₈O, ≥99.5%) were obtained from Sigma-Aldrich (St. Louis, MI, USA); hydrogen peroxide (H₂O₂, 30% w/w) from Panreac Química SLU (Barcelona, Spain); iron(II) sulfate heptahydrate (FeSO₄·7H₂O, 99%), tetramethylammonium hydroxide (TMAOH, ≈10 w/w) ortho-phosphoric acid (H₃PO₄, 85%) and ammonium hydroxide (NH₄OH, 28%) from Fluka (Buchs, Switzerland), ethanol (C₂H₅OH, 99.9%) and acetone (C₃H₆O, ≥99%) were purchased from Fischer (Waltam, MA, USA) and oleic acid (extra pure) from Merck (Kenilworth, NY, USA). Milli-Q deionized water (Millipore, Burlington, MA, USA) was used to prepare the different solutions and reaction media. hydrogen peroxide (H₂O₂, 30%), Reactive Blue 19 (RB19, 50%), methyl green (MG, 85%), estrone (E1, ≥99%), 17β-estradiol (E2, ≥98%) and 17α-ethinylestradiol (EE2, ≥98%) were purchased from Sigma-Aldrich (St. Louis, MI, USA).

17β-estradiol (≥98.0%), 17α-ethinylestradiol (≥98.0%), bisphenol A (≥99.0%), 4-tert-octylphenol (≥99.0%), and acetonitrile HPLC grade were purchased from Sigma-Aldrich (St. Louis, MO, USA). Water HPLC grade was acquired from Tedia Company (Fairfield, OH, USA). The main characteristics of the studied compounds are shown in Table 1.Table 1

Characteristics of the studied xenoestrogens.

Table 1

	Chemical formula	Molecular mass (g mol−1)	Log Kow	Solubility (mg L−1)	Use	MPCa proposed by the European Parliament
E2	C18H24O2	272.38	4.0	28.0	Natural estrogen	0.001 µg L−1[3]
EE2	C20H24O2	296.40	3.6	11.3	Synthetic estrogen	0.035 ng L−1[4]
BPA	C15H16O2	228.29	3.3	120	Plasticizer	0.01 µg L−1[3]
4TOP	C14H22O	206.32	5.2	5.0	Surfactant	2 µg L−1[5]

a

Maximum permissible concentration in surface water.

Corn oil (#C8267) and 17α-ethinylestradiol (#E4876; CAS 57-63-6) were purchased from Sigma–Aldrich Canada Ltd. (Oakville, Ontario, Canada). Genistein (#G-6055; CAS 446-72-0) was purchased from LC- laboratories (Woburn, MA, United States). All chemicals were certified with a purity ≥98% by the provider. Concentrated stock solutions of EE2 (160 μg/ml) and GE (800 mg/ml) were prepared in dimethyl sulfoxide (DMSO), aliquoted and stored in amber glass bottles at -80°C. Working solutions were prepared daily by diluting stock solutions 200 times in Corn oil (0.5% final DMSO concentration).