Yeh K Y
Endocrinology. 1984 Oct;115(4):1364-70. doi: 10.1210/endo-115-4-1364.
Transfer of corticosterone from serum to milk was studied in lactating rats after ether and pentobarbital anesthesia. Two minutes after the onset of anesthesia stress, total serum and milk corticosterone concentrations were not significantly different. By 30 min, corticosterone concentrations in serum increased to a peak and plateaued at about this level during the 2-h experimental period, while concentrations in milk reached a maximal plateau only at 50 min poststress. The peak corticosterone concentrations in serum and milk were 76 +/- 6 and 36 +/- 4 micrograms/dl, respectively. By centrifugal ultrafiltration dialysis, the percentages of free corticosterone in serum and milk were not significantly different at the maximal concentrations; thus, free corticosterone in serum was about 200% of that in milk. In contrast, anesthesia stress had no effect on serum and milk corticosteroid-binding globulin concentrations; the serum to milk ratio was approximately 10:1. No accumulation of corticosterone in milk was observed after repeated ether stress. Decreases in milk corticosterone levels after recovery from ether stress paralleled that of its serum counterpart. These results indicate that corticosterone concentrations in milk increase rapidly after ether stress, but are limited to a level significantly lower than that in serum. The possible effects of corticosterone in milk on the development of infant rats remains to be defined.
在乙醚和戊巴比妥麻醉后的泌乳大鼠中研究了皮质酮从血清向乳汁的转移。麻醉应激开始后两分钟，血清和乳汁中的总皮质酮浓度无显著差异。到30分钟时，血清中的皮质酮浓度升至峰值，并在2小时的实验期内维持在该水平，而乳汁中的浓度仅在应激后50分钟达到最大稳定水平。血清和乳汁中皮质酮的峰值浓度分别为76±6和36±4微克/分升。通过离心超滤透析，在最大浓度时血清和乳汁中游离皮质酮的百分比无显著差异；因此，血清中的游离皮质酮约为乳汁中的200%。相比之下，麻醉应激对血清和乳汁中皮质类固醇结合球蛋白的浓度没有影响；血清与乳汁的比例约为10:1。反复乙醚应激后未观察到乳汁中皮质酮的积累。从乙醚应激恢复后，乳汁中皮质酮水平的下降与其血清中的下降情况平行。这些结果表明，乙醚应激后乳汁中的皮质酮浓度迅速升高，但限于显著低于血清中的水平。乳汁中皮质酮对幼鼠发育的可能影响仍有待确定。
