[The measurement of dializable free testosterone].

Non-protein bound testosterone is considered to represent an active androgen in blood, and it reflects in androgenicity. We measured the dializable free testosterone (AFT) in various disorders. The values of plasma testosterone (T), fractional free testosterone (%FT) and AFT were 560 +/- 151 (mean +/- SD) ng/dl 1.9 +/- 0.4% and 10.7 +/- 3.3 ng/dl in normal males (n = 43, aged 25-58), 51 +/- 12 ng/dl, 1.2 +/- 0.3% and 0.6 +/- 0.2 ng/dl in normal females (n = 30, aged 21-41), and 63 +/- 26 ng/dl, 0.6 +/- 0.3% and 0.4 +/- 0.2 ng/dl in pregnancy (n = 20, second and third trimester), respectively. Those values in normal females and pregnancy were significantly lower than those in normal males (p less than 0.001). In male, the concentrations of T and AFT in patients with primary (n = 43, aged 18-50) and secondary hypogonadism (n = 16, aged 22-66) were significantly decreased (p less than 0.001 vs normal males), respectively. The plasma concentration of total testosterone (T) was increased 1032 +/- 269 ng/dl in chronic hepatitis (p less than 0.001) (n = 21, aged 28-52) and 1455 +/- 366 ng/dl in hyperthyroidism (p less than 0.001) (n = 44, aged, 18-52). However, %FT in those disorders was significantly decreased 1.2 +/- 0.3% in chronic hepatitis (p less than 0.001) and 0.8 +/- 0.3% in hyperthyroidism (p less than 0.001), and plasma levels of AFT in both disorders were not different as compared with that in normal males.(ABSTRACT TRUNCATED AT 250 WORDS)