title: Beta-carotene uptake and changes in ovarian steroids and uterine proteins during the estrous cycle in the canine.
abstract: The uptake of beta-carotene by reproductive tissues and the effects of beta-carotene on reproductive function in the dog are unknown. We studied the uptake of beta-carotene by blood, corpus luteum, and uterine endometrium and the role of dietary beta-carotene in influencing ovarian steroid and uterine protein production during the estrous cycle in the dog. Mature female Beagle dogs (n = 56) were fed diets containing 0, 2, 20, or 50 mg of beta-carotene daily for approximately 6 wk before estrus detection. Blood was sampled at regular intervals from estrus through d 45 after ovulation (d 0 = ovulation), when laparotomy was performed. The ovaries were obtained for the isolation of corpus luteum. The uterus was flushed with phosphate-buffered saline and the endometrium obtained by scraping. Beta-carotene was not detectable in plasma, corpus luteum, or endometrium of unsupplemented dogs. However, beta-carotene and alpha-carotene in plasma, corpus luteum, and uterine endometrium increased in a dose-dependent manner. Alpha-carotene made up a high percentage of total carotenoids even though the alpha-carotene content in the dietary source was very low. Dogs fed 50 mg of beta-carotene had significantly higher concentrations of plasma progesterone between d 12 and 26 compared with unsupplemented dogs. Dietary beta-carotene did not influence plasma estradiol-17beta and total uterine proteins. Therefore, beta-carotene is absorbed into plasma, corpus luteum, and uterine endometrium of dogs. Furthermore, dietary beta-carotene increased plasma progesterone concentrations during the estrous cycle. It is possible that dietary beta-carotene may improve reproductive function in the canine.
authors.affiliation: Department of Animal Sciences, Washington State University, Pullman 99164-6351, USA.
authors.forename: B C
authors.initials: BC
authors.lastname: Weng
authors.forename: B P
authors.initials: BP
authors.lastname: Chew
authors.forename: T S
authors.initials: TS
authors.lastname: Wong
authors.forename: J S
authors.initials: JS
authors.lastname: Park
authors.forename: H W
authors.initials: HW
authors.lastname: Kim
authors.forename: A J
authors.initials: AJ
authors.lastname: Lepine
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D003338:Corpus Luteum / Q000378:metabolism; D004285:Dogs / Q000378:metabolism*; D004717:Endometrium / Q000378:metabolism; D004958:Estradiol / Q000097:blood; D004971:Estrus; D005260:Female; D010053:Ovary / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D011863:Radioimmunoassay / Q000662:veterinary; D013256:Steroids / Q000378:metabolism*; D014599:Uterus / Q000378:metabolism*; D019207:beta Carotene / Q000493:pharmacokinetics*
chemical_list: D011506:Proteins; D013256:Steroids; D019207:beta Carotene; D004958:Estradiol