A Simplified Method for Measuring the Binding Capacity of Sex Hormone-Binding Globulin in Human Serum and Its Clinical Application

Abstract We describe a simple, rapid method for measurement of sex-hormone binding globulin. Serial dilutions of pregnancy serum are prepared in serum from males that has been pre-treated by heating to 60 degrees C for 1 h to destroy endogenous binding globulin, which is then determined by a long-used technique to yield a set of "standards." In the assay itself, a fixed amount of [3H]-labeled and unlabeled dihydrotestosterone is incubated with standard or unknown, and the bound fraction precipitated with saturated ammonium sulfate. A plot of percent of the steroid bound vs standard dilution yields a sigmoid curve, from which the results in unknowns can be read by simple extrapolation. Within-assay CVs for pools of serum from men, women, and women in late pregnancy were 6.56, 9.59, and 8.4%, respectively. Between-assay CVs for the same pools were 8.05, 9.5, and 11.5%, respectively. The correlation between results obtained by this method and those of the older technique was 0.95 for samples from non-pregnant subjects and 0.73 for those from pregnant women. Our procedure is simpler and faster than previous methods and accurately measures the differences in the globulin in sera from men, women, and pregnant women. Forty to 50 samples can be assayed in a working day.

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Relationships of serum lipoproteins and apoproteins to sex hormones and to the binding capacity of sex hormone binding globulin in healthy finnish men

Metabolism ◽

10.1016/0026-0495(86)90011-9 ◽

1986 ◽

Vol 35 (6) ◽

pp. 535-541 ◽

Cited By ~ 61

Author(s):

E. Hämäläinen ◽

H. Adlercreutz ◽

C. Ehnholm ◽

P. Puska

Keyword(s):

Sex Hormones ◽

Binding Capacity ◽

Sex Hormone ◽

Sex Hormone Binding Globulin ◽

Hormone Binding ◽

Serum Lipoproteins

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Binding of Testosterone and Oestradiol to Sex Hormone Binding Globulin, Human Serum Albumin and other Plasma Proteins: Evidence for Non-Specific Binding of Oestradiol to Sex Hormone Binding Globulin

Clinical Science ◽

10.1042/cs0640307 ◽

1983 ◽

Vol 64 (3) ◽

pp. 307-314 ◽

Cited By ~ 29

Author(s):

M. Jawed Iqbal ◽

Maureen Dalton ◽

Robert S. Sawers

Keyword(s):

Human Serum Albumin ◽

Serum Albumin ◽

Human Serum ◽

Binding Site ◽

Plasma Proteins ◽

Specific Binding ◽

Sex Hormone ◽

Sex Hormone Binding Globulin ◽

Normal Female ◽

Hormone Binding

1. The percentage binding of testosterone (T) and oestradiol (E2) to sex hormone binding globulin (SHBG) and human serum albumin (HSA) was determined over a range of SHBG concentrations of 16–250 nmol of dihydrotestosterone (DHT) bound/l. It was found that the binding of both T and E2 to HSA was a function of their binding to SHBG and bore an inverse relationship to it. After removal of both SHBG and HSA from plasma by affinity chromatography a ‘residual’ binding of about 11% for T and 12% for E2 was still apparent. in addition to the specific high-affinity, low capacity binding of E2 to SHBG, non-specific low-affinity binding of 7–12% was demonstrated after selective denaturation of the specific binding site of the latter. 2. Competition studies indicated that although at the relatively higher levels of SHBG found in the normal female the physiological concentrations of E2, T and DHT need not be taken into account in estimating the unbound fractions of steroids, at the relatively lower levels of SHBG found in normal men and hirsute women, the physiological concentrations of T and DHT are effective in causing statistically significant displacement of E2 from the common, specific binding site on SHBG. 3. A simple computerized technique is described for the determination of fractions of E2 and T respectively, that are unbound to SHBG, unbound to SHBG and HSA, and unbound to all plasma proteins, when the total plasma levels of E2, T, DHT and SHBG are known.

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