[Study on luteal insufficiency by the two-step LH-RH test]

To clarify both the releasing function and the self-priming effect of LH-RH on gonadotropins of the anterior pituitary gland, two step administration of 100 micrograms of synthetic LH-RH at a 60 minutes interval (two step LH-RH test) was carried out in 29 women with luteal insufficiency, 10 women in luteal phase just after spontaneous abortion, 12 women in puerperium and 24 women with normal menstrual cycles. Native LH, FSH and their subunits were measured by radioimmunoassay and serum progesterone (P), estradiol (E2) and prolactin (PRL) were also measured before administration of LH-RH. By defining hormone release (1st peak level-0' level) as delta 1, self-priming effect (2nd peak level-60' level) as delta 2 and delta 2/delta 1 as delta 1 delta 2 ratio, in the luteal insufficiency group, especially in the cases with lower of serum P and E2, delta 1 was significantly higher and the delta 1 delta 2 ratio was lower than those in the control group. In the abortion group, delta 1 and delta 2 were similar to those in the control group, indicating rapid recovery of the anterior pituitary function. In the puerperium group (approximately 1 month after delivery), delta 1 was higher and the delta 1 delta 2 ratio was lower than those in the control group. This suggests that the puerperium is more or less similar to the period of luteal insufficiency. The results also indicate that the two step LH-RH test can be one of the useful methods for the study of luteal insufficiency in terms of the pituitary gonadotropin synthesis and release.