title: Research note: changes in the concentration of beta-carotene, alpha-tocopherol and retinol in the bovine corpus luteum during the ovarian cycle.
abstract: Causes and possible consequences of the accumulation of beta-carotene during the development of the corpus luteum in cattle are still unknown. Therefore, in a descriptive study a total of 43 corpora lutea from ovaries of non-pregnant cows representing four stages of the ovarian cycle the concentration of beta-carotene, alpha-tocopherol and retinol was determined. Beta-carotene and alpha-tocopherol continuously increased from stage I to stage IV (beta-carotene: 14 +/- 8 vs. 175 +/- 117 microg/g, P < 0.05; alpha-tocopherol: 15 +/- 7 vs. 132 +/- 66, P < 0.001). In contrast, retinol decreased from highest values at stage I (250 +/- 160 ng/g) to lowest (90 +/- 80 ng/g tissue) at stage III (P < 0.05). The results support the concept, that both beta-carotene and alpha-tocopherol accumulation in the corpus luteum secondary to the uptake of lipoprotein-bound cholesterol during steroid synthesis. Lowest retinol levels were observed at highest metabolic activity of the corpus luteum indicating a possible consumption of retinol during stereogenesis. In conclusion assuming an importance of a local conversion of beta-carotene into retinol in the corpus luteum dietary supplementation should be sufficient enough to support such an accumulation of beta-carotene in the corpus luteum as local precursor of retinol.
authors.affiliation: Department of Physiology and Pathophysiology, Institute of Nutritional Science, University of Potsdam, Potsdam-Rehbrücke, Germany. fjschwei@rz.uni-potsdam.de
authors.forename: F J
authors.initials: FJ
authors.lastname: Schweigert
mesh_terms: D000818:Animals; D002417:Cattle / Q000378:metabolism / Q000502:physiology*; D003338:Corpus Luteum / Q000737:chemistry*; D030762:Estrous Cycle / Q000378:metabolism*; D005260:Female; D005298:Fertility / Q000502:physiology; D006080:Ovarian Follicle / Q000378:metabolism; D014801:Vitamin A / Q000032:analysis*; D024502:alpha-Tocopherol / Q000032:analysis*; D019207:beta Carotene / Q000032:analysis*
chemical_list: D019207:beta Carotene; D014801:Vitamin A; D024502:alpha-Tocopherol