Lawrence J L, Payton R R, Godkin J D, Saxton A M, Schrick F N, Edwards J L
Department of Animal Science, The University of Tennessee, Knoxville 37996-4574, USA.
J Dairy Sci. 2004 Aug;87(8):2449-54. doi: 10.3168/jds.S0022-0302(04)73368-8.
The objectives of this study were to evaluate: 1) effects of a physiologically relevant elevated temperature on in vitro development of maturing oocytes, 2) effects of retinol on in vitro development of maturing oocytes, and 3) effects of retinol to improve development of oocytes compromised by an elevated temperature. Bovine oocytes were matured for 24 h at 38.5 or 41.0 degrees C (first 12 h) in 0 or 5 microM retinol. After insemination, cleavage and blastocyst development were assessed on d 3 and 8, respectively. Temperature, retinol, and their interaction were included in the statistical model. Culture of oocytes at 41.0 degrees C decreased the proportion of 8- to 16-cell embryos and increased that of 2-cell embryos. In addition, culture at 41.0 degrees C decreased the ability of oocytes to develop to the blastocyst stage. Blastocysts derived from oocytes cultured at 41.0 degrees C had fewer total nuclei. In 3 of the 7 experimental replicates, effects of 41.0 degrees C to reduce blastocyst development were minimal (difference in the development of the control vs. heat stress group was <20%). To provide a more precise test of our hypothesis (retinol administration may improve development of oocytes compromised by heat stress), data were analyzed, including only those replicates (n = 4) in which heat stress reduced development to blastocyst >20%. When this was done, a significant temperature x retinol interaction was noted. The addition of retinol to the maturation medium prevented heat-induced reductions in development of oocytes to blastocyst stage. Results indicate that retinol may protect oocytes from some of the deleterious effects of heat stress.
1）生理相关的高温对成熟卵母细胞体外发育的影响；2）视黄醇对成熟卵母细胞体外发育的影响；3）视黄醇改善受高温影响的卵母细胞发育的效果。将牛卵母细胞在含有0或5微摩尔视黄醇的条件下，于38.5或41.0摄氏度（前12小时）成熟培养24小时。授精后，分别在第3天和第8天评估卵裂和囊胚发育情况。统计模型中纳入了温度、视黄醇及其相互作用因素。在41.0摄氏度培养卵母细胞会降低8至16细胞胚胎的比例，并增加2细胞胚胎的比例。此外，在41.0摄氏度培养会降低卵母细胞发育至囊胚阶段的能力。来自在41.0摄氏度培养的卵母细胞的囊胚总细胞核较少。在7个实验重复中有3个，41.0摄氏度降低囊胚发育的影响极小（对照组与热应激组发育差异<20%）。为了更精确地检验我们的假设（给予视黄醇可能改善受热应激影响的卵母细胞的发育），仅分析了那些热应激使囊胚发育降低>20%的重复实验数据（n = 4）。这样做时，发现了显著的温度×视黄醇相互作用。在成熟培养基中添加视黄醇可防止热诱导的卵母细胞发育至囊胚阶段的减少。结果表明视黄醇可能保护卵母细胞免受热应激的一些有害影响。
