부산대학교 도서관

Fractionation and identification of cortisol in the plasma, using the steroid binding properties of competitive protein binding employing Gel filtration and insoluble adsorbent (Lloyd's reagent) are now widely carried out. Namely, the addition' of an increasing amount of unlabeled cortisol to an equilibrium dialysis system containing standard plasma and a constant amount of cortisol-1, 2-311 exerts a proportional decrease in the percentage of cortisol-1, 23-H bound to the plasma protein.On the other hand, preparations of plasma containing unknown amounts of cortisol also decrease binding. The cortisol content could thus be determined by a standard curve. These methods required 1 ml and 0.1 ml of test plasma and gave a standard deviation of 0~80 midi and 0~40 mμg/ml, respectively. In the present paper the plasma cortisol determinations were carried out on samples from 195 subjects by the method of Gel filtration and Lloyd's reagent. After extracting the cortisol 1 ml or 0.1 ml by ethylalcohol it was measured according to its competition with tritiated cortisol for binding sites on the corticosteroid binding globulin of female plasma. The concentration of total cortisol was measured in maternal and cordal plasma, as well as in healthy female subjects and in inpatients by the method of Gel filtration and Lloyd's reagent.The comparisons of the data by Gel filtration and Lloyd's reagent are shown as follows. Plasma cortisol concentration by the method of Lloyd's reagent was higher than that of Gel filtration except in cordal plasma. Plasma cortisol concentrations in healthy subjects (7.74±3.04 μg/dl) by Gel filtration and (11.21±12.15 μg/dl) by Lloyd's reagent were lower than those in inpatients (11.50±3.68 μg/ di) by Gel filtration and (17.67±2.90μg/dl) by Lloyd's reagent. It was observed that cortisol concentration of cordal plasma (42.64±8.60 μg/dl) by the method of Gel filtration was higher than maternal plasma (34.99±11.81 μg/dl) by the method of Lloyd's reagent. Cortisol concentration in cordal plasma (17.40±16.37 μg/dl) by the method of Lloyd's reagent, however, was lower than that of maternal (39.67±12.00 μg/dl) by the method of Lloyd's reagent.Cortisol is known to be the corticoid present in the largest amount in the female plasma and its concentration to be increased following the administration of ACTH.Unbound cortisol levels in the maternal and cordal plasma were higher than those in healthy non-pregnant.Both unbound and bound cortisol levels in the maternal and cordal plasma increased by chronic stress, but the elevation of cortisol levels in the maternal and cordal plasma was not observed by acute stress. It is generally assumed that the placenta acts as a barrier which allows only maternal cortisol to transfer the fetal circulation.