Normal Plasma LH Research Articles

Case with Small Tests Associated with Skeletal Dysplasia.

We report an 18-year-old Japanese male with severe short stature and small testes. The endocrinological examination showed high plasma FSH value and normal plasma LH value, consistent with impaired spermatogenesis, and a skeletal X-ray survey suggested systemic bone dysplasia. Analysis of DAZ and FSH receptor genes was not confirmatory of the cause of defects in the seminiferous tubule maturation in this patient. The unique association of impaired spermatogenesis and skeletal dysplasia in the patient has not previously been described.

Longitudinal evaluation of the different gonadotropin pulsatile patterns in anovulatory cycles of young girls

We studied 13 adolescents (mean gynecological age 29.2 +/- 14.1 months) with anovulatory cycles and 7 women with ovulatory cycles (mean gynecological age 33.1 +/- 15.3 months) as a control group. Adolescents with anovulatory cycles were grouped on the basis of mean plasma LH values: group 1 (n = 7) with high LH values, and group 2 (n = 6) with normal LH values. In all women plasma gonadotropin concentrations were measured at 10-min intervals for 8 h on day 4 of the cycle. Pulsatile gonadotropin secretion was also studied in each subject a second time 40 months later, to establish the outcome of the different pulsatile patterns. Group 1 had more frequent and greater LH pulses than the other two groups (which were similar) and had the highest plasma 17 beta estradiol, testosterone, androstenedione, and 17 hydroxyprogesterone concentrations. Longitudinal control showed that: in group 1, three subjects out of seven acquired ovulatory cycles and there was a fall in mean LH plasma levels (30 +/- 5 vs. 9 +/- 4 IU/L; P less than 0.01), number of pulses (8.3 +/- 1.5 vs. 5 +/- 0; P less than 0.025), mean amplitude (13 +/- 3 vs. 5 +/- 2 IU/L; P less than 0.02) and an increase in interpulse interval (56 +/- 10 vs. 91 +/- 6 min; P less than 0.01). In four subjects anovulatory cycles persisted and the LH pulsatile profile remained unchanged. In group 2, five subjects out of six acquired ovulatory cycles, but there were no significant changes in the number of pulses (6 +/- 1 vs. 6 +/- 2; P = NS), interpulse interval (97 +/- 30 vs. 85 +/- 30 min; P = NS), or amplitude (5 +/- 2 vs. 4 +/- 2 IU/L; P = NS). The results indicate that: 1) anovulatory young women with early normal plasma LH values have an adequate GnRh pulsatile pattern which will easily lead to ovulation; 2) anovulatory young women with high LH plasma values may have a reproductive system blocked in a pathological condition, similar to that observed in polycystic ovary syndrome; 3) only few subjects with high plasma LH values are able to achieve ovulation and normalize LH pulsatile pattern as a consequence of a new mode of GnRh release.

Longitudinal evaluation of the different gonadotropin pulsatile patterns in anovulatory cycles of young girls.

We studied 13 adolescents (mean gynecological age 29.2 +/- 14.1 months) with anovulatory cycles and 7 women with ovulatory cycles (mean gynecological age 33.1 +/- 15.3 months) as a control group. Adolescents with anovulatory cycles were grouped on the basis of mean plasma LH values: group 1 (n = 7) with high LH values, and group 2 (n = 6) with normal LH values. In all women plasma gonadotropin concentrations were measured at 10-min intervals for 8 h on day 4 of the cycle. Pulsatile gonadotropin secretion was also studied in each subject a second time 40 months later, to establish the outcome of the different pulsatile patterns. Group 1 had more frequent and greater LH pulses than the other two groups (which were similar) and had the highest plasma 17 beta estradiol, testosterone, androstenedione, and 17 hydroxyprogesterone concentrations. Longitudinal control showed that: in group 1, three subjects out of seven acquired ovulatory cycles and there was a fall in mean LH plasma levels (30 +/- 5 vs. 9 +/- 4 IU/L; P less than 0.01), number of pulses (8.3 +/- 1.5 vs. 5 +/- 0; P less than 0.025), mean amplitude (13 +/- 3 vs. 5 +/- 2 IU/L; P less than 0.02) and an increase in interpulse interval (56 +/- 10 vs. 91 +/- 6 min; P less than 0.01). In four subjects anovulatory cycles persisted and the LH pulsatile profile remained unchanged. In group 2, five subjects out of six acquired ovulatory cycles, but there were no significant changes in the number of pulses (6 +/- 1 vs. 6 +/- 2; P = NS), interpulse interval (97 +/- 30 vs. 85 +/- 30 min; P = NS), or amplitude (5 +/- 2 vs. 4 +/- 2 IU/L; P = NS). The results indicate that: 1) anovulatory young women with early normal plasma LH values have an adequate GnRh pulsatile pattern which will easily lead to ovulation; 2) anovulatory young women with high LH plasma values may have a reproductive system blocked in a pathological condition, similar to that observed in polycystic ovary syndrome; 3) only few subjects with high plasma LH values are able to achieve ovulation and normalize LH pulsatile pattern as a consequence of a new mode of GnRh release.

Different gonadotropin pulsatile fashions in anovulatory cycles of young girls indicate different maturational pathways in adolescence.

To characterize the spectrum of pulsatile gonadotropin secretion during the postmenarchal period, we studied 24 adolescents whose gynecological age was 1-4 yr. Six women with ovulatory cycles formed a control group. Eighteen women with anovulatory cycles were grouped on the basis of mean plasma LH values: group 1 (n = 8) with high LH values and group 2 (n = 10) with normal LH values. In all women, plasma gonadotropin concentrations were measured at 10-min intervals for 8 h on day 4 of the cycle. Pulsatile gonadotropin secretion was also studied a second time in 7 women from group 1 and 7 from group 2 after 5 days of progesterone (P) in oil treatment to assess the role of P in regulating gonadotropin secretion in the postmenarchal period. Group 1 had more frequent and greater LH pulses than the other two groups (which were very similar) and had the highest plasma 17 beta-estradiol, testosterone (T), androstenedione (A), and 17-hydroxyprogesterone concentrations. In all anovulatory women, basal LH values were correlated with the LH interpulse interval (r = -0.65; P less than 0.01) and pulse amplitude (r = 0.86; P less than 0.001). LH pulse amplitude was correlated with basal 17 beta-estradiol values (r = 0.74; P less than 0.001), and LH interpulse interval with basal T (r = -0.83; P less than 0.001), A (r = -0.51; P less than 0.05), and 17-hydroxyprogesterone (r = -0.79; P less than 0.001) values. P administration decreased LH pulse frequency and increased LH pulse amplitude more in group 2 than in group 1 with high LH values; a clear reduction was also found in A, T, and 5 alpha-dihydrotestosterone values. These results indicate that 1) anovulatory young women with high plasma LH values have an alternative maturational pathway, different from that of anovulatory women with normal plasma LH values, who are similar to ovulatory adolescents; 2) the pulsatile pattern of gonadotropin secretion has specific roles linked separately to amplitude and frequency in controlling ovarian steroidogenesis, which accounts for the endocrine differences between groups; and 3) in the postmenarchal period, by modulating LH and FSH pulsatility and thus reducing androgen levels and their atretic action on follicles, P may be a basic regulatory factor in enhancing functional cyclicity.

Circadian variations of luteinizing hormone can have two different profiles in adolescent anovulation.

The circadian profile of plasma LH concentrations was investigated in 12 healthy anovulatory adolescent women by drawing blood samples every 20 min for 24 h during the early follicular phase. Plasma 17 beta-estradiol, testosterone, and androstenedione levels were measured in the first sample. Ovarian size was measured by ultrasound. According to their mean plasma LH levels, the adolescents were divided into two groups, those with a high plasma LH level (2 Sd or greater than the mean adult value) and those with a normal plasma LH level. The mean plasma estradiol (P less than 0.001) and testosterone (P less than 0.05) levels were higher in the women with high plasma LH levels compared to those in women with normal plasma LH levels. The LH pulse amplitude was greater (P less than 0.05) and the interpulse interval shorter (P less than 0.025) in the high LH group compared to those in the normal LH group. A 24-h periodicity with the highest plasma LH levels and the greatest pulse amplitude in the afternoon was found in high LH group. In the normal LH group, the highest plasma LH levels and greatest pulse amplitude occurred in the first hours of the morning. An accentuated 24-h LH periodicity is typical of puberty, but disappears in adulthood. We have recorded the persistence of pronounced LH circadian changes in anovulatory adolescent women which might be a marker of a continuing maturational process. Furthermore, LH circadian changes have opposing profiles according to the mean LH values, suggesting the presence of different central nervous system pubertal programs.

Evidence for Leydig Cell Dysfunction in Infertile Men with a Selective Increase in Plasma Follicle-Stimulating Hormone*

Recent studies in acutely castrated males of several species have demonstrated that testosterone (T) alone, given in doses that produce normal plasma T levels, can maintain normal plasma FSH and LH levels. This suggests that a nonsteroidal factor from the seminiferous tubule is not required to regulate FSH release, and raises the possibility that Leydig cell function may not be fully normal in oligo- or azoospermic men with increased plasma FSH levels. To clarify this, we studied T production rates in 11 sexually mature, infertile, but otherwise healthy men who had increased plasma FSH and normal plasma LH, T, and estradiol levels and in 9 normal men. Although individual plasma T and LH levels in the infertile men were within the normal ranges, the mean plasma T level of the infertile men was significantly lower (P less than 0.002), and the mean plasma LH level was significantly higher (P less than 0.002) than values in the normal men. The infertile men also had significantly lower plasma free T concentrations (P less than 0.005), while sex hormone-binding globulin and estradiol levels were similar to those of the normal men. The production rate of T in the infertile men was half that in the normal men (P less than 0.001). We conclude that T production is significantly reduced in infertile men who have a selective increase in plasma FSH. Because of the known role of Leydig cell sex steroids in the negative feedback control of FSH, this finding may explain the elevated plasma FSH concentrations characteristic of men with germ cell loss without the need to postulate a deficiency of a separate seminiferous tubule factor.

Effect of ovariectomy on plasma LH, FSH, estradiol, and progesterone and medial basal hypothalamic LHRH concentrations old and young rats.

Resting plasma concentrations of LH, FSH, estradiol, and progesterone and medial basal hypothalamic concentrations of LHRH (MBH-LHRH) were measured by RIA in 8- to 12-month-old female rats which had begun to exhibit constant estrous (CE) or prolonged diestrous (PD) vaginal smear patterns and compared to young cycling rats on proestrus, estrus, or diestrus. In addition, we examined the effect of ovariectomy on these hormonal profiles. Old CE rats have normal plasma LH, FSH and progesterone concentrations, but exhibit elevated estradiol levels and decreased MBH-LHRH concentrations compared to young cycling rats on the day of estrus. Ovariectomy results in an attenuated rise in plasma LH and FSH and a much lesser decrease in MBH-LHRH when compared to young rats, despite comparable steroid changes. Old PD rats have normal LH and FSH levels,but have elevated estradiol and progesterone concentrations and decreased MBH-LHRH levels when compared to young rats on the day of diestrus. Ovariectomy causes a normal decrease in MBH-LHRH; however, the increased gonadotropin levels are significantly less than seen in young controls.

Gonadotropin secretion in prepubertal and pubertal primary hypogonadism: response to LHRH.

Plasma LH and FSH were measured before and after LHRH administration in 10 patients with Turner's syndrome, in 7 with anorchia, in 2 castrates, in 18 with Klinefelter's syndrome, and in 11 prepubertal subjects with unilateral cryptochidism used as a control group. Basal LH was elevated in 4 and basal FSH in 8 of 10 patients with Turner's syndrome. Four patients with anorchia showed elevations of LH while FSH had increased in all of them. The two castrates had normal or slightly increased basal LH and definite elevations of FSH. Prepubertal subjects with Klinefelter's syndrome had normal plasma LH and FSH levels, but showed a marked elevation when they developed puberty. After LHRH administration, mean LH increased by 297% and FSH by 81% in Turner's syndrome, while in anorchia LH increased 757% and FSH 104%. After LHRH administration, patients with unilateral cryptorchidism had an LH increment of 316% and a FSH increment of 164%. Patients with prepubertal Klinefelter's syndrome showed elevations of 261% for LH and 221% for FSH after LHRH treatment. Adolescent subjects with Klinefelter's syndrome had an increment of 352% for LH and only 13% for FSH after LHRH administration. We have concluded that patients without functioning gonads fail to suppress gonadotropin secretion even before puberty while the gonads of the prepubertal Klinefelter's syndrome are able to control LH and FSH release. After puberty, in spite of the hypersection of LH and FSH observed in all subjects with agonadism there is a large pituitary reserve of the gonadotropins. We suggest that the relative inability of pubertal patients with Klinefelter's syndrome to increase FSH after LHRH treatment might be due to the presence of an abnormal compound secreted by the gonads.