The renal clearance of follicle-stimulating and luteinizing hormone in postmenopausal women

The renal clearance of follicle-stimulating and luteinizing hormone (FSH, LH) was studied in seven postmenopausal women. The clearance values for FSH ranged from 0.16 to 0.70 (mean 0.58) ml/min, and those for LH from 0.03 to 0.26 (mean 0.14) ml/min. Thus the mean FSH clearance was 4.1 times greater than the LH clearance. The difference was statistically confirmed by the Wilcoxon test.

Similarly the mean FSH/LH ratio was four times higher in urine than in plasma when results were expressed in terms of NIH-FSH-S2 and NIH-LH-S3, or in terms of the 2nd International Reference Preparation for Human Menopausal Gonadotrophin. Consequently, the plasma contained relatively more LH than the corresponding urine samples. A nonspecific effect of plasma proteins on the bioassay of FSH and LH was excluded.