Sex-hormone-binding globulin and albumin concentrations in human cerebrospinal fluid.
Polyacrylamide gel electrophoresis of plasma and concentrated cerebrospinal fluid (CSF) preincubated with tritium labelled 5 alpha-dihydrotestosterone (DHT) showed identical migration of the radioactivity, indicating the presence of sex-hormone-binding globulin (SHBG) in human CSF. The concentrations of SHBG (measured as the binding capacity) and albumin were measured in concentrated CSF (12 women and 1 man) and samples of plasma of some patients (9 women). SHBG could not be detected in 6 of the CSF samples, and the mean value of the determinable samples was 42.3 +/- 13.4 pmol/l. The mean +/- SE of the SHBG concentration in plasma was 90.8 +/- 8.9 nmol/l and the mean albumin concentrations in CSF and plasma were 3.4 +/- 0.6 mumol/l and 670 +/- 107 mumol/l respectively. The distribution ratio for SHBG over the blood-CSF barrier was 10 times higher than for albumin. It was concluded that the SHBG-binding in the CSF is negligible but that the albumin-binding may contribute to the CSF concentrations of testosterone and estradiol, which are 10-25% above the plasma unbound concentrations.
D000328:Adult; D000368:Aged; D000418:Albumins / Q000134:cerebrospinal fluid*; D001812:Blood-Brain Barrier; D002556:Cerebrospinal Fluid Proteins / Q000032:analysis; D013196:Dihydrotestosterone / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012738:Sex Hormone-Binding Globulin / Q000134:cerebrospinal fluid*; D014316:Tritium
D000418:Albumins; D002556:Cerebrospinal Fluid Proteins; D012738:Sex Hormone-Binding Globulin; D013196:Dihydrotestosterone; D014316:Tritium