Fairclough R J, Liggins G C
J Endocrinol. 1975 Dec;67(3):333-41. doi: 10.1677/joe.0.0670333.
Binding of cortisol to plasma proteins was studied in the foetal lamb by equilibrium dialysis at 37 degrees C. At 122 days of pregnancy the mean level of transcortin expressed as cortisol-binding capacity was 28 +/- 6 (S.D.) ng cortisol/ml plasma. During the last 14 days of pregnancy there was a progressive increase in transcortin-binding capacity to 85 +/- 14 ng cortisol/ml plasma. A sharp increase in the concentration of both protein-bound and unbound cortisol was observed over the same period. A rise in the concentration of total cortisol from around 3 to 42 ng/ml was associated with an increase in unbound cortisol from 0-2 to a maximum of 2-1 ng/ml. The concentration of albumin-bound cortisol was approximately equal to that of unbound cortisol. The mean value for the transcortin-cortisol affinity constant was 1-15 x 10(8) l/mol. It is concluded that an increase in transcortin-binding capacity is partly responsible for the prepartum increase of corticosteroid levels observed in normal foetal lambs.
通过在37摄氏度下进行平衡透析，研究了胎羊中皮质醇与血浆蛋白的结合情况。在妊娠122天时，以皮质醇结合能力表示的皮质素结合球蛋白平均水平为28±6（标准差）纳克皮质醇/毫升血浆。在妊娠的最后14天，皮质素结合球蛋白结合能力逐渐增加至85±14纳克皮质醇/毫升血浆。在同一时期，观察到蛋白结合皮质醇和游离皮质醇的浓度均急剧增加。总皮质醇浓度从约3纳克/毫升升至42纳克/毫升，同时游离皮质醇从0 - 2纳克/毫升增加到最高2 - 1纳克/毫升。白蛋白结合皮质醇的浓度约等于游离皮质醇的浓度。皮质素结合球蛋白 - 皮质醇亲和常数的平均值为1 - 15×10⁸升/摩尔。得出的结论是，皮质素结合球蛋白结合能力的增加部分导致了正常胎羊产前观察到的皮质类固醇水平升高。
