URINARY EXCRETION OF INTERSTITIAL-CELL STIMULATING HORMONE BY NORMAL MALES AND FEMALES OF VARIOUS AGES*

Abstract
ICSH activity in the urine of normal males and females of various ages has been determined semi-quantitatively by means of an assay which depends upon the repair of ventral prostatic atrophy in the hypophysectomized immature male rat. The testicular weights of the animals were also recorded as an index of FSH activity. The findings were as follows: (a) In 12 pre-pubertal children, urinary ICSH activity was barely detectable in 3 instances, (b) In 5 adult females, ICSH activity was detectable in mid-cycle, and in 3 of the 5 subjects it was detectable during the follicular and luteal phases as well. There was no appreciable difference between the excretion rates of ICSH during the follicular and luteal phases. However, during mid-cycle a twofold to fourfold increase in ICSH activity occurred, (c) In 17 adult males, ICSH activity was detectable in 16 instances. The excretion of ICSH in hospital patients appeared to be lower than in healthy volunteers. Although the results were variable, it appeared that males excreted appreciably more ICSH than adult females, except when the latter were in the mid-cycle peak phase of the menstrual cycle, (d) In 10 postmenopausal women, the rate of excretion of ICSH was higher than that observed in any other age group of either sex. (e) The increases in testicular and ventral prostatic weights were produced by the same dose of urine concentrate in most instances, suggesting a rough equivalence between the amounts of FSH and ICSH excreted.