Divergent effects of the antiestrogen tamoxifen and of estrogens on luteinizing hormone (LH) pulse frequency, but not on basal LH levels and LH pulse amplitude in men.

We studied the role of estrogens on LH pulse modulation in men in two ways. Firstly, we compared LH pulse frequency and amplitude in 13 normal men before and after 6 weeks administration of the antiestrogen tamoxifen (10 mg twice daily). Secondly, we compared LH pulse frequency and amplitude between a group of 10 agonadal men not receiving sex steroid treatment and a group of 9 agonadal men (male to female transsexuals) continuously treated with 50 micrograms ethinyl estradiol/day. Tamoxifen administration to normal men resulted in a significant rise in the mean serum LH level from 5.7 +/- 1.3 (+/- SD) to 10.1 +/- 2.4 U/L, which was associated with significant increases in LH pulse frequency (from 4.2 +/- 1.5 to 5.8 +/- 1.7/7 h) and LH pulse amplitude (from 3.8 +/- 0.9 to 4.6 +/- 0.7 U/L). In the group of agonadal men the mean LH pulse frequency was 6.8 +/- 1.5/7 h, while it was 5.9 +/- 1.7/7 h in the estrogen-treated agonadal group (P = NS). The mean serum LH level and LH pulse amplitude were, however, significantly lower in the estrogen-treated agonadal men than in the agonadal men (14.7 +/- 7.0 vs. 34.3 +/- 8.6 and 4.1 +/- 1.8 vs. 7.4 +/- 1.8 U/L, respectively). We conclude that estrogens reduce basal LH levels and LH pulse amplitude. With regard to the modulation of LH pulse frequency our data provide contradictory results. While an antiestrogen increased LH pulse frequency in normal men, estrogen alone produced no change in LH pulse frequency in agonadal men. The study design in the agonadal men ignores the possible interaction of the two major testicular hormones (estradiol and testosterone) on gonadotropin secretion. Therefore, a possible explanation for this discrepancy in the effects of antiestrogen and estrogen could be an interaction between estrogens and androgens on gonadotropin secretion at the level of the LHRH pulse generator.

Estrogen-induced prolactinoma in a man.

Prolactinomas can be induced in rats by large doses of estrogens. Whether prolactinomas can be induced in humans by estrogens, however, is not known. This report describes the development of a prolactinoma in a man with previously normal plasma PRL levels after the administration of pharmacological doses of estrogen. The patient, a 26-yr-old male to female transsexual, took cyproterone acetate (100 mg/day, orally) and ethinyl estradiol (100 micrograms/day, orally) for 10 months and (surrepititiously) estradiol-17-undecanoate (100 mg, twice weekly, im) for about 6 of the 10 months. Plasma PRL levels rose from 0.05 to 5.20 U/L within 10 months (normal, 0.05-0.30 U/L). A computed tomographic scan showed a pituitary mass with suprasellar extension. After all estrogen therapy was discontinued, his plasma estradiol levels gradually declined from 2.8 to 0.77 nmol/L (normal, 0.04-0.12 nmol/L), but PRL levels rose further to 6.2 U/L. Bromocriptine treatment (2.5 mg twice daily) then was given. Plasma PRL fell gradually to 0.43 U/L and a computed tomographic scan after 5 months showed reduction in tumor size. The patient then discontinued bromocriptine treatment. Four months later his plasma estradiol level was normal, while plasma PRL had risen to 4.6 U/L, indicating autonomous PRL secretion. We conclude that 1) estrogen in pharmacological doses can induce prolactinomas in man; and 2) subjects treated with high doses of estrogen must, therefore, be surveyed for the development of such tumors.

Effects of long-term testosterone administration on gonadotropin secretion in agonadal female to male transsexuals compared with hypogonadal and normal women.

We investigated the effects of long term testosterone (T) administration on pulsatile gonadotropin secretion in agonadal women and the effects of estradiol (E2) on gonadotropin secretion in eugonadal women in the follicular phase of the menstrual cycle. We studied 4 groups: A) 28 eugonadal women in the early follicular phase of the menstrual cycle, B) 11 hypogonadal women, C) 13 agonadal female to male (f-t-m) transsexuals treated for at least 3 months with 120-160 mg T undecanoate (TU)/day, orally, and D) 5 agonadal f-to-m transsexuals treated for at least 6 months with 250 mg of a mixture of testosterone esters, im (im T-esters), every 2 weeks. The eugonadal women in the early follicular phase had a mean serum E2 level of 193 +/- 94 (+/- SD) pmol/L, significantly higher (P less than 0.01) than that in the hypogonadal women (60 +/- 24 pmol/L), whereas there was no difference in the mean serum T levels (1.8 +/- 0.7 vs. 2.3 +/- 1.5 nmol/L). the higher serum E2 level in the eugonadal women was associated with a significantly lower mean serum LH level (6.9 +/- 2.6 vs. 44.6 +/- 17.6 U/L; P less than 0.01) and LH pulse amplitude (2.8 +/- 1.0 vs. 12.6 +/- 4.8 U/L; P less than 0.01), whereas the mean nadir LH interval did not differ between the two groups (75 +/- 29 vs. 81 +/- 49 min). The mean serum T level in the agonadal f-to-m transsexuals treated with oral TU was significantly higher (P less than 0.01) than that in the hypogonadal women (9.7 +/- 4.7 vs. 2.3 +/- 1.5 nmol/L). In spite of this elevated T level there was no difference in the mean serum LH level (38.4 +/- 14.7 vs. 44.6 +/- 17.6 U/L), LH pulse amplitude (14.3 +/- 5.7 vs. 12.6 +/- 4.8 U/L), or nadir LH interval (72 +/- 27 vs. 81 +/- 49 min) in these groups. Also, the mean serum E2 (64 +/- 16 vs. 60 +/- 24 pmol/L and FSH levels (62 +/- 17 vs. 64 +/- 28 U/L) did not differ between these groups. Treatment of the agonadal f-to-m transsexuals with im T-esters resulted in mean serum T and E2 levels of 34.4 +/- 27.0 nmol/L and 121 +/- 54 pmol/L, respectively, both significantly higher (P less than 0.01) than those in groups B and C.(ABSTRACT TRUNCATED AT 400 WORDS)

Pregnancy after prolonged pulsatile administration of luteinizing hormone-releasing hormone in a patient with clomiphene-resistant secondary amenorrhea.

Induction of ovulation with LRH, self-administered by the patient (20 microgram every 2 h, iv) from 0700-2300 h continuously for 90 days, is described. Three ovulatory cycles resulted, and the patient conceived during the third cycle. The morning serum LH and FSH concentrations showed a pattern similar to that seen in normal cycles. Total urinary estrogen and pregnanediol excretion did not differ from those in normal cycles. This observation shows that the described mode of treatment is feasible and can result in normal intrauterine pregnancy.

The effects of long term testosterone administration on pulsatile luteinizing hormone secretion and on ovarian histology in eugonadal female to male transsexual subjects.

Polycystic ovarian disease (PCOD) is associated with elevated serum LH and (sub)normal FSH levels, while serum androgen levels are often elevated. To clarify the role of androgens in this abnormal pattern of gonadotropin secretion, LH secretion was studied in 1) 9 eugonadal female to male transsexual subjects before and during long term (6 months) testosterone (T) administration (250 mg/2 weeks, im), and 2) in a woman with an androgen-secreting ovarian tumor both before and after surgical removal of the tumor. Finally, we studied the effects of high serum androgen levels on ovarian histology in 3) 26 transsexual subjects after long term (9-36 months) T administration (250 mg/2 weeks, im) to assess whether T-induced ovarian abnormalities are similar to those that occur in women with PCOD. Long term T treatment in the nine female to male transsexual subjects resulted in increases in the mean serum T level from 1.7 +/- 0.8 (+/- SD) to 40.8 +/- 31.9 nmol/L (P less than 0.01), the mean serum dihydrotestosterone level from 0.6 +/- 0.2 to 3.3 +/- 1.5 nmol/L (P less than 0.02), and the mean serum free T level from 9.5 +/- 5.2 to 149 +/- 46 pmol/L (P less than 0.02). Mean serum estrone and estradiol levels were similar before and during T treatment. The mean serum LH level decreased from 6.3 +/- 2.0 to 2.9 +/- 1.1 U/L (P less than 0.01), and the mean FSH levels decreased from 6.6 +/- 2.0 to 3.7 +/- 2.2 U/L (P less than 0.02). Pulsatile LH secretion before and during T treatment was studied in five subjects. Neither the mean nadir LH interval nor the LH pulse amplitude changed significantly in these five subjects. The serum T level in the woman with the androgen-secreting ovarian tumor was 9.6 nmol/L, and it declined to normal after removal of the tumor. Her mean serum LH and FSH levels, the mean nadir LH interval, and LH pulse amplitude were in the normal range before and after removal of the tumor. Studies of ovarian histopathology in 26 transsexual subjects after long term androgen treatment revealed multiple cystic follicles in 18 subjects (69.2%), diffuse ovarian stromal hyperplasia in 21 subjects (80.8%), collagenization of the tunica albuginea in 25 subjects (96.2%), and luteinization of stromal cells in 7 subjects (26.9%). Findings consistent with criteria for the pathological diagnosis of polycystic ovaries, that is 3 of the 4 findings listed above, were present in 18 of the 26 subjects (69.2%).(ABSTRACT TRUNCATED AT 400 WORDS)

Luteinizing hormone secretion patterns in boys at the onset of puberty measured using a highly sensitive immunoradiometric assay.

Pulsatile LH secretion was studied in 3 prepubertal and 11 early pubertal boys by measuring plasma LH concentrations at 10-min intervals from 1200-1800 h and from 2400-0600 h using an immunoradiometric assay with a lower limit of detection of 0.10 IU/L. Plasma testosterone (T) was measured hourly. In the prepubertal boys plasma LH was not detectable during the daytime but at night 20- to 300-min periods of detectable, but low (less than 0.5 IU/L) plasma LH values occurred. A discrete episodic LH pattern was discernible, and the median number of pulses was 2 during the 6-h nocturnal sampling periods. Plasma T was not detectable (less than 1.0 nmol/L). In the pubertal boys most daytime plasma LH values were greater than 0.3 IU/L, with periods of values of 0.1-0.3 IU/L and short periods of undetectable levels as well. At night definite pulses, up to 4.7 IU/L, were found in all boys. The median number of pulses was 4 during the 6-h nocturnal sampling period. Plasma T was detectable at night in 5 of these 11 boys. The results strongly suggest that at the onset of puberty prepubertal boys (G1) have no LH secretion during the day but intermittent gonadotrophic activity during the night. In early puberty LH secretion increases in amplitude as well as frequency to a clear pulsatile pattern during the night, sometimes with pulses during the day as well.

Sex steroids and pulsatile luteinizing hormone release in men. Studies in estrogen-treated agonadal subjects and eugonadal subjects treated with a novel nonsteroidal antiandrogen.

This study evaluated the effects of estrogens and androgens on LH pulse frequency and amplitude in male subjects. To assess the role of estrogens we compared the serum LH pulse frequency and amplitude between 3 groups: 8 agonadal subjects receiving no steroid treatment; 6 agonadal subjects continuously treated with 50 micrograms ethinylestradiol/day; and 17 eugonadal men. Mean serum LH levels and LH pulse amplitude were significantly lower in the agonadal subjects receiving estrogens (14.8 +/- 5.4 (SD) U/L and 4.1 +/- 1.5 U/L, respectively) than in the group of agonadal subjects not receiving sex steroid treatment (35.7 +/- 8.4 U/L and 7.3 +/- 2.0 U/L, respectively). The mean LH pulse frequency was 7.1 +/- 1.5/7 h in the group not receiving sex steroid treatment and 6.0 +/- 1.4/7 h in the group receiving estrogens (P NS). The LH pulse frequency in the eugonadal men (3.8 +/- 1.3/7 h) was significantly lower than the frequency in both groups of agonadal subjects. The LH pulse amplitude was of the same magnitude in the estrogen-treated agonadal subjects and in eugonadal men (4.1 +/- 1.5 U/L and 3.5 +/- 1.2 U/L, respectively). The role of androgens was studied in 15 eugonadal male subjects (who presented for female role reassignment) by determining the effects of a novel nonsteroidal androgen receptor blocker, Anandron, on basal and LH-releasing hormone (LHRH)-stimulated serum LH/FSH levels; LH pulse frequency and amplitude; sex steroid and sex hormone-binding globulin levels; and serum PRL levels during an 8-week period. Basal and LHRH-stimulated LH levels and testosterone rose progressively during the first 6 weeks and reached a plateau thereafter, while estradiol levels continued to increase somewhat. The LH pulse amplitude and frequency had increased after 6 weeks (3.1 +/- 0.6 vs. 4.5 +/- 1.2 U/L and 4.4 +/- 2.4 vs. 6.6 +/- 1.1 pulses/7 h, respectively). Basal FSH levels were not affected while LHRH-stimulated FSH levels progressively decreased from 2 to 6 weeks, after which they did not change. Along with the rise of estradiol levels an increase of sex hormone-binding globulin and PRL levels occurred.(ABSTRACT TRUNCATED AT 400 WORDS)

Pulsatile luteinizing hormone patterns in the follicular phase of the menstrual cycle, polycystic ovarian disease (PCOD) and non-PCOD secondary amenorrhea.

To characterize the oscillations of plasma LH in normally cycling and amenorrheic women, three groups of women were studied: I, normal women during the follicular phase of the cycle (n = 9); II, women with polycystic ovarian disease (PCOD; n = 11); and III, women with non-PCOD secondary amenorrhea (n = 12). Blood samples were obtained at 10-min intervals for 6 h on 2 separate days. A pulse was defined as an increase in LH at least 20% over the preceding lowest value (nadir). Since LHRH release immediately follows the nadir of the LH levels, the nadir interval (NI) was used for analysis. For analysis, the results from 1 day were selected at random from each subject, and from each day, the same number of NIs also were randomly selected. When two NIs from each patient were selected, the median NI was 75 min in group I, 45 min in group II, and 45 min in group III. When three or four NIs were chosen, the median NI was 60 min in group I, 50 min in group II, and 40 min in group III. The differences between the groups were statistically significant. When three NIs were selected, the mean of the corresponding LH amplitudes was 2.8 U/liter in group I, 6.0 U/liter in group II, and 1.5 U/liter in group III. The differences between these groups were statistically significant. Thus, the NI in PCOD patients was shorter than that during the follicular phase of the cycle, but this short NI is not unique for PCOD, since the NI in non-PCOD secondary amenorrhea patients was even smaller. The LH amplitude was higher in PCOD and lower in non-PCOD secondary amenorrhea compared to that during the follicular phase of the cycle. The decrease in NI in PCOD and/or non-PCOD secondary amenorrhea vs. the NI of the follicular phase could be explained by either a higher frequency of LHRH pulses from the hypothalamus or an increased sensitivity of the pituitary leading to a greater response of the pituitary to LHRH pulses.

Somatostatin inhibits prolactin release from the lactotroph primed with oestrogen and cyproterone acetate in man.

The present study investigated the effect of administration of somatostatin (SRIF) on the release of prolactin in men. No effect was observed when SRIF was administered to eugonadal men. Release of prolactin was inhibited, however, when SRIF was administered to oestrogen-treated agonadal subjects (male-to-female trans-sexuals) and to an even greater degree when subjects had been pretreated with a combination of oestrogen and cyproterone acetate. This is consistent with findings in the rat. Thus in man, as in the rat, SRIF can inhibit prolactin secretion, but only after treatment with oestrogen.

Patterns of LH and FSH in men during high-frequency blood sampling.

The aim of the study was to test the hypothesis that in serial determinations of concentrations of LH and FSH involving blood samples taken every minute, the observed pulses of LH and FSH which last less than 3-4 min might not be a physiological phenomenon but part of the 'noise' of the radioimmunoassay or blood-sampling technique. Blood was sampled every minute for a period of 90 min in six men. During the first 45 min, blood was sampled by means of vacuum tubes only. During the second 45 min, sampling took place with a syringe via a rubber stopper, either using a tourniquet (n = 3) or flushing the cannula with heparinized saline. Three criteria were used to identify variations in the patterns of LH and FSH as true hormonal changes. First, a threshold was used which had to be exceeded by the difference between nadir and maximum values before a pulse could be identified. An average of approximately six pulses per 90 min was found in both the LH and FSH series. The majority of these pulses lasted less than 3-4 min. In two subjects, larger LH pulses of longer duration were measured. Secondly, differences between duplicate measurements of nadir and/or maximum values of more than one-third of the amplitude of a pulse were considered unacceptable. This involved about 75% of the pulses. Thirdly, the reproducibility of the hormone variations was estimated. In one subject, concentrations of LH were measured four times in four separate assays.(ABSTRACT TRUNCATED AT 250 WORDS)

Estrogen positive feedback on LH secretion in transsexuality.

In order to test the hypothesis whether there is variation in hormonal levels or response to hormonal manipulation that could permit a distinction between heterosexuals and transsexuals, we designed the following protocol: Six male-to-female (m-to-f) transsexuals, six heterosexual control females and six female-to-male (f-to-m) transsexuals were given estradiol benzoate (E2B) (4.5 micrograms/kg/12 hr) for five days. In the female population, E2B treatment was initiated on day 5 of the menstrual cycle. In all the subjects blood luteinizing hormone (LH) and follicle stimulating hormone (FSH), estradiol-17 beta (E2) and testosterone (T) levels were measured twice daily. Additionally, LH and FSH responses to LHRH (100 micrograms iv) stimulation prior to and on day 5 of the E2B treatment were evaluated. In the m-to-f transsexuals, T levels decreased sharply and progressively during estrogen treatment, along with a fall in LH and FSH levels. The magnitude of the LH and FSH responses to LHRH stimulation also decreased following estrogen administration. In the heterosexual female controls and in the f-to-m transsexuals, estrogen administration increased LH levels to a minimum of 100% above initial values from day 3 onwards. Interestingly, the magnitude of the LH increase in the f-to-m transsexuals was greater than that of the heterosexual female controls. In both groups, LHRH stimulation resulted in a greater LH response compared to that prior to estrogen treatment. Our present observations, based on blood hormonal levels and responses to hormonal manipulations do not permit a distinction between heterosexual females and f-to-m transsexuals. There was no convincing evidence for the existence of a positive estrogen feedback on LH secretion in m-to-f transsexuals. These results contradict some of the reported hypotheses concerning hormonal alterations in these individuals.

Induction of first cycles in primary hypothalamic amenorrhea with pulsatile luteinizing hormone-releasing hormone: a mirror of female pubertal development.

During pubertal development in girls, the attainment of regular ovulatory menstrual cycles usually is preceded by cycles that are either anovulatory or show a defective luteal phase. It is not known whether these defective cycles are caused by inadequate luteinizing hormone-releasing hormone (LH-RH) secretion or by an inadequate response of the pituitary-ovarian axis to LH-RH stimulation. To shed new light on this matter, the authors analyzed endocrine data from 12 menstrual cycles induced by pulsatile LH-RH therapy in five women with primary amenorrhea of hypothalamic origin. Anovulatory cycles occurred with and without an increase in estrogen excretion and with and without a luteinizing hormone surge. In addition, ovulatory cycles with and without deficient corpus luteum function were observed. Most of these types of anovulatory and ovulatory menstrual cycles also have been described during normal puberty. Therefore, these observations suggest that, during normal pubertal development, maturation of the pituitary gonadotropes and of the ovary occurs, as well as the increased secretion of LH-RH from the hypothalamus, which the overall process depends upon.

Ovulation induction with pulsatile luteinizing releasing hormone in women with clomiphene citrate-resistant polycystic ovary-like disease: clinical results.

Eighty-four treatment units were given to 11 women with clomiphene citrate-resistant polycystic ovarian disease (PCOD). PCOD was defined as oligomenorrhea elevated luteinizing hormone (LH), normal follicle-stimulating hormone (FSH), and preference-elevated androgens. Luteinizing-releasing hormone (LRH) was administered intravenously via a portable infusion pump. Doses varied between 5 and 40 micrograms/pulse given at 60-, 90-, or 120-minute intervals. In 11 women, 85 treatment units (TUs) were completed, of which 74 were ovulatory, showing no specific advantage of any particular pulse dose or pulse interval. Five pregnancies occurred in three women. Two women did not ovulate during 52 and 284 consecutive days of therapy, respectively. Oligomenorrheic patients with PCOD can be made more regular by means of LRH, not necessarily leading to a regular menstrual cycle. In general, LRH is sufficient for luteal support. No signs of hyperstimulation were observed, although two patients incidently developed unilocular cysts with a maximum diameter of 8 cm. Ovulation induction with LRH in PCOD is possible, although the disease itself does not change during therapy. This may be further evidence that altered hypothalamic LRH secretion is more the result, rather than the cause, of the phenomenon of PCOD.

Short-term pituitary desensitization to luteinizing hormone-releasing hormone (LH-RH) after pulsatile LH-RH administration in women with amenorrhea of suprapituitary origin.

The existence of a short-term pituitary desensitization in luteinizing hormone (LH) release to single doses of luteinizing hormone-releasing hormone (LH-RH) in the ovariectomized rat was recently disclosed. The purpose of the present study was to investigate whether this refractoriness is also present in humans. Blood from six women with amenorrhea of suprapituitary origin was sampled every 10 minutes for 300 minutes for determination of LH and follicle-stimulating hormone (FSH). A pulse of 20 micrograms LH-RH was given intravenously 90 and 210 minutes after the first blood sample, and 2 micrograms LH-RH was given 30, 150, 240, and 270 minutes after t0. The mean maximal increments of LH and FSH were compared. The LH response to a 2-micrograms LH-RH bolus given 30 (t240) or 60 (t150) minutes after a 20-micrograms LH-RH pulse was significantly decreased, compared with the initial response to this dose at t30. For both LH and FSH, the response to 2 micrograms LH-RH given 30 minutes after the 20-micrograms pulse (t240) was almost absent, compared with 60 (t150) minutes after the 20-micrograms dose. We conclude that a short-term pituitary refractoriness to LH-RH is present after administration of single pulses of LH-RH in women with amenorrhea of suprapituitary origin and pulses of LH-RH in the physiologic range (2 micrograms) given to these women do not always generate LH and FSH increments that are identifiable as significant hormone pulses.