Schweigert F J
Department of Physiology and Pathophysiology, Institute of Nutritional Science, University of Potsdam, Potsdam-Rehbrücke, Germany.
Arch Tierernahr. 2003 Aug;57(4):307-10. doi: 10.1080/00039420310001594388.
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.
牛黄体发育过程中β-胡萝卜素积累的原因及可能后果仍不清楚。因此，在一项描述性研究中，从代表卵巢周期四个阶段的未怀孕母牛的卵巢中总共采集了43个黄体，测定了其中β-胡萝卜素、α-生育酚和视黄醇的浓度。从第一阶段到第四阶段，β-胡萝卜素和α-生育酚持续增加（β-胡萝卜素：14±8 vs. 175±117微克/克，P<0.05；α-生育酚：15±7 vs. 132±66，P<0.001）。相比之下，视黄醇从第一阶段的最高值（250±160纳克/克）降至第三阶段的最低值（90±80纳克/克组织）（P<0.05）。结果支持了这样一种概念，即β-胡萝卜素和α-生育酚在黄体中的积累是类固醇合成过程中脂蛋白结合胆固醇摄取的继发结果。在黄体代谢活性最高时观察到视黄醇水平最低，这表明在甾体生成过程中视黄醇可能被消耗。总之，假设在黄体中β-胡萝卜素局部转化为视黄醇很重要，那么饮食补充应该足以支持黄体中β-胡萝卜素作为视黄醇的局部前体的这种积累。
