A Source of Error in Gonadotropic Hormone Determihations. ∗

This report is presented in an effort to show that determinations for gonadotropic hormone content of the urine are frequently erroneous due to the precipitation of contaminating amounts of fat-insoluble or combined estrogen.

Concerning urinary gonadotropins there is no doubt that pregnant women excrete a substance capable of producing corpora lutea in the ovaries of normal infantile animals. Some women in the menopause excrete a gonadotropic hormone capable of provoking follicle growth in the ovaries of hypophysectomized rats or mice. A gonadotropic hormone prepared from the pituitary and capable of interstitial cell stimulation has been described, but its detection if present in the urine, depends also upon the use of hypophysectomized animals. For studying the urine of non-pregnant women most workers have resorted to the use of intact animals and depend upon more cursory and unreliable criteria for the estimation of gonadotropic hormone. Speaking collectively, their criteria have been the appearance, in infantile rats or mice as old as 32 days and within periods up to as long as 130 hours after injection, of follicle growth, interstitial cell hypertrophy, increase in uterine and ovarian size and weight, establishment of vaginal introitus, and estrus. The reactions in the lower tubular tract have been interpreted as gonadotropic responses in some instances, in the absence of demonstrable changes in the gonads.

The uterus and its endometrium depend upon the ovaries for changes in histologic structure. If the uterus of an infantile rodent were stimulated directly without the medium of the ovaries but in their presence, by an estrogenic substance that does not in any way depress ovarian activity, then an independent activation of the ovaries by the animal's own pituitary might occur. Hypothetically this pituitary activity can be construed as being either independent and spontaneous, or as a result of stimulation by an estrogen.