Send to

Choose Destination
Contraception. 1974 Dec;10(6):599-605.

Plasma concentrations of free and non-TeBG bound testosterone in women on oral contraceptives.



Differential precipitation of plasma proteins after equilibration of the plasma with tracer amounts of testosterone (T) was used to measure free and not-T-estradiol binding globulin (TeBG)-bound T in 20 women and 10 men. Tritiated T was the tracer used. Comparison of this method with the equilibration dialysis method produced a good agreement in accuracy. The method is described as simple and reproducible, allowing routine assay of 20 plasma samples in duplicate by 1 technician. Normal values for men were 497 ng/100 ml (total T), 42 ng/100 ml(free T), 137 ng/100 ml (non-TeBG bound), and .5 mcg/100 ml (TeBG). Women's values were 52 ng/100 ml (Total T), 2.6 ng/100 ml (free T), 5 ng/100 ml (nonTeBG) and .9 mcg/100 ml (TeBG). Significant increases in total (p less than .05), free (p less than .01), non-TeBG-bound (p less than .05), and TeBG-T (p less than .01) were found for women taking norethindrone and mestranol. Women taking norgestrel-ethinyl estradiol had significant increase (p less than .01) in non-TeBG-bound T. It is concluded that estrogens increase the binding capacity of TeBG, and this is inhibited by norgestrel.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center