Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 11 de 11
Filter
Add more filters










Publication year range
1.
J Clin Endocrinol Metab ; 85(9): 3271-5, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10999821

ABSTRACT

Controversial effects of weight reduction on gonadotropin secretion in obesity have been reported. As a result of pulsatility, single serum samples or frequent sampling studies are somewhat limited with regard to monitoring LH and FSH concentrations. We studied follicular phase nocturnal urinary (nu) LH and FSH secretion and glucose metabolism (150-min euglycemic hyperinsulinemic clamp) during 1 menstrual cycle/30-day period before and after weight reduction in 10 severely overweight infertility patients (age, 29 +/- 3.1 yr; body mass index, 37.1 +/- 3.3 kg/m2; +/-SEM). A 6-week very low calorie diet was followed by a 4-week normocaloric period. The urinary LH and FSH results reported represent samples taken 12 to 2 days before the LH surge, or 10 consecutive samples in the case of amenorrhea. We observed a decrease of 8% (P < 0.001) in percent body fat mass and a 5% (P < 0.005) reduction in waist to hip ratio. Mean nu-LH decreased by 45% [6.06 +/- 1.05 (+/-SEM) to 3.22 +/- 0.71 IU/L], whereas mean nu-FSH remained unchanged. Insulin-stimulated glucose uptake increased by 41% (P < 0.01), which was accounted for by a significant increase in nonoxidative glucose disposal (P = 0.003). Serum sex hormone-binding globulin concentrations increased by 39% (P < 0.01), and insulin-like growth factor (IGF)-binding protein-1 (IGFBP-1) levels increased by 46% (P < 0.05). Fasting serum insulin concentrations decreased by 38%, those of leptin by 37%, those of androstenedione by 32%, those of testosterone by 20% (all P < 0.01), and those of dehydroepiandrosterone sulfate by 13% (P < 0.05). The percent change in nu-LH correlated negatively with glucose uptake (r = -0.76; P < 0.01) and the increase in serum sex hormone-binding globulin (r = -0.85; P < 0.005) and positively with the percent change in waist to hip ratio (r = 0.79; P < 0.01). The absolute nu-LH levels after weight reduction correlated significantly with fasting insulin concentrations (r = 0.88; P < 0.001) and negatively with glucose uptake (r = -0.67; P < 0.05). No significant relationships were found between absolute levels or changes in nu-LH concentrations and leptin, IGF-I, IGFBP-3, or IGFBP-1 concentrations. Our findings suggest that weight reduction with a very low calorie diet results in a decrease in nu-LH concentrations, a reduction in the LH/FSH ratio, and FSH predominance favoring folliculogenesis. The decrease in LH concentrations is inversely related to the severity of insulin resistance. It is possible that the decrease in LH secretion with weight reduction is more dependent on the absolute levels of insulin sensitivity than on the degree of general adiposity.


Subject(s)
Insulin Resistance/physiology , Luteinizing Hormone/blood , Obesity/physiopathology , Weight Loss/physiology , Adult , Blood Glucose/metabolism , Body Composition/physiology , Female , Follicle Stimulating Hormone/urine , Humans , Insulin/blood , Insulin-Like Growth Factor Binding Proteins/blood , Insulin-Like Growth Factor I/metabolism , Leptin/blood , Luteinizing Hormone/urine , Obesity/blood , Steroids/blood
2.
Hum Reprod ; 14(11): 2709-15, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10548606

ABSTRACT

A randomized comparison of two recombinant human follicle-stimulating hormone (recFSH) preparations (Gonal-F and Puregon) in ovarian stimulation for in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) was carried out at the Infertility Clinic of the Family Federation of Finland. A total of 348 women (aged 22-43 years) suffering from infertility due to miscellaneous causes was recruited. Of these, 344 underwent stimulation using equal starting doses (150 IU/day: Gonal-F n = 164, Puregon n = 158 or 300 IU/day: Gonal-F n = 8, Puregon n = 14) after down-regulation with intranasal buserelin from the mid-luteal phase. Similar clinical pregnancy rates were achieved with both preparations; 33.5% per cycle and 37.4% per embryo transfer (24.5% one-embryo and 75.5% two-embryo transfers, n = 147) with Gonal-F (150 IU/day) and 32.9% per cycle and 36.4% per embryo transfer (30.1% one-embryo and 69.9% two-embryo transfers, n = 145) with Puregon (150 IU/day). The ongoing cumulative pregnancy rates after frozen-thawed embryo transfer were 35.4% with Gonal-F and 37.7% with Puregon. Six cycles were cancelled because of a low response (three in each group). Similar numbers of oocytes were obtained in both groups; 13.0 with 150 IU/day and 6.1 with 300 IU/day Gonal-F, and 12.4 with 150 IU/day and 7.1 with 300 IU/day Puregon. The fertilization and cleavage rates and the incidence of moderate or severe ovarian hyperstimulation syndrome (Gonal-F, 2.0% and Puregon, 0.7%) were also similar. Gonal-F and Puregon were equally and highly effective in stimulation for IVF and ICSI.


Subject(s)
Fertilization in Vitro , Follicle Stimulating Hormone/therapeutic use , Ovulation Induction , Adult , Embryo Transfer , Female , Follicle Stimulating Hormone/administration & dosage , Follicle Stimulating Hormone/adverse effects , Follicle Stimulating Hormone, Human , Humans , Infertility/therapy , Ovarian Hyperstimulation Syndrome/etiology , Pregnancy , Prospective Studies , Recombinant Proteins/administration & dosage , Recombinant Proteins/adverse effects , Recombinant Proteins/therapeutic use , Sperm Injections, Intracytoplasmic
3.
J Clin Endocrinol Metab ; 84(9): 3135-9, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10487676

ABSTRACT

The satiety factor leptin is expressed in several reproductive tissues, but its role in the control of reproductive physiology is not well understood. We studied leptin concentrations in the sera and follicle fluids of 52 women [body fat mass percentage (BFM%) range, 19.6-38.8%] undergoing pituitary down-regulation and ovarian hyperstimulation for in vitro fertilization (IVF) treatment. Fasting serum samples were collected 1) at maximal suppression before the initiation of gonadotropin treatment, 2) at maximal ovarian hyperstimulation, 3) at the time of oocyte retrieval, and 4) 16 days later when all subjects were under exogenous luteal support using 600 mg progesterone daily. Follicular fluid (FF) was obtained at oocyte retrieval from two representative preovulatory follicles in both ovaries. During ovarian hyperstimulation there was a significant 60% increase in serum leptin concentrations from 10.9 +/- 1.1 (SEM) to 15.7 +/- 1.5 ng/mL (P < 0.01) between suppression and maximal hyperstimulation, demonstrating that the ovarian functional state can affect serum leptin concentrations. A serum leptin increase of 22-198% during ovarian hyperstimulation was evident in 43 subjects, whereas in 9, leptin concentrations remained unchanged. A positive correlation between leptin change and BFM% (r = 0.55; P < 0.0005) was observed in the 43 leptin responders. The follicular fluid leptin level was similar to that in serum. In separate linear regression analysis, BFM% contributed to 59-64%, body mass index to 46-56%, and weight to 46-55% (all P < 0.001) of the variability in leptin concentrations at the 4 time points. The 20-fold increase in serum estradiol concentrations during IVF was not significantly correlated with changes in leptin concentrations. On the contrary, the relative serum leptin increase was negatively associated with the ovarian response to hyperstimulation, as revealed by the numbers of follicles (b = -0.28; r2 = 8.1%; P < 0.05) and oocytes retrieved (b = -0.39; r2 = 15.2%; P < 0.01). This relationship was further reflected in a positive correlation between the percent increases in leptin and FSH concentrations (r = 0.39; P < 0.01). The significant relationship of high leptin and reduced ovarian response was also maintained when the cumulative dose of FSH was used as a covariable. Reduced ovarian response was not a function of body mass index, BFM%, basal leptin levels, or insulin concentrations. Fasting serum insulin concentrations remained unchanged in response to IVF, but were positively correlated to serum leptin concentrations at all four time points. Our data suggest that leptin production may be influenced by the ovarian functional state. During IVF a high relative leptin increase is associated with adiposity and a reduced ovarian response. These observations support the possibility that high leptin concentrations might reduce ovarian responsiveness to gonadotropins. Hence, leptin might explain in part why obese individuals require higher amounts of gonadotropins than lean subjects to achieve ovarian hyperstimulation.


Subject(s)
Adipose Tissue , Body Composition , Fertilization in Vitro , Follicular Fluid/metabolism , Ovary/physiology , Proteins/metabolism , Adult , Body Constitution , Body Mass Index , Estradiol/blood , Fasting , Female , Follicle Stimulating Hormone/administration & dosage , Follicle Stimulating Hormone/blood , Humans , Leptin , Linear Models , Ovulation Induction , Proteins/analysis
4.
J Clin Endocrinol Metab ; 81(8): 2854-64, 1996 Aug.
Article in English | MEDLINE | ID: mdl-8768842

ABSTRACT

The basic tenet of this investigation was that obesity is not a prerequisite in the development of polycystic ovary syndrome (PCOS), as indicated by the fact that 50% of PCOS women are not obese. Further, obesity itself is a disease entity with the common manifestation of insulin resistance/hyperinsulinemia with PCOS. Given recent evidence that insulin and GH may have gonadotropin-augmenting effects, we have determined the common and distinguishing features of neuroendocrine-metabolic dysfunctions of lean [body mass index (BMI), < 23 kg/m2] and obese (BMI, > 30 kg/m2) women with the classical form of PCOS. Insulin sensitivity, as determined by rapid i.v. glucose tolerance testing; 24-h dynamics of insulin/glucose levels, somatotropic [GH/GH-binding protein/insulin-like growth factor I (IGF-I)/IGF-binding proteins (IGFBP)], and LH axes; and their downstream effects on ovarian steroids were simultaneously assessed in eight lean PCOS and eight obese PCOS patients and an equal number of BMI-matched normal cycling controls. Our results show that insulin sensitivity was reduced 50% (P < 0.01) in lean PCOS from that in lean controls. There was a further decrease in obese controls (P < 0.01) and a 2-fold greater reduction (P < 0.001) in obese PCOS than in obese controls, suggesting that insulin resistance (IR) is a common lesion in PCOS, and that obesity contributes an additional component to IR in obese PCOS. Consistent with the degree of IR, the manifestation of compensatory hyperinsulinemia in lean PCOS was incipient, being evident only in response to meals (P < 0.05), and became overt during the 24-h fasting/feeding phases of the day in obese control (P < 0.001) with a 2- to 3-fold greater elevation (P < 0.001) in obese PCOS. An enhanced early insulin response to glucose occurs equally in obese control (P < 0.01) and obese PCOS (P < 0.05), but not in their lean counterparts. Considering the more profound IR and the associated hyperglycemia in obese PCOS, the magnitude of the early insulin release is inadequate, suggesting that beta-cell dysfunction exists in obese PCOS. Remarkable differences in the somatotropic axis were also observed; although 24-h GH pulse frequency and levels of IGF-I and IGFBP-3 were unaltered by either PCOS or obesity, the 24-h mean GH pulse amplitude was increased by 30% (P < 0.01) in lean PCOS in the presence of normal levels of high affinity GHBP and normal GH response to GHRH. In distinct contrast, the somatotropic axis in both obese control and obese PCOS was profoundly modified, with attenuation of GH pulse amplitude (P < 0.001) and GH response to GHRH (P < 0.001), resulting in a state of hyposomatotropinism with a more than 50% reduction (P < 0.001) of 24-h mean GH levels. In addition, GHBP levels were elevated 2-fold and were correlated inversely with GH (r = -0.81) and positively with insulin (r = 0.75) concentrations. IGFBP-I levels were suppressed in both obese groups, with a 4-fold greater reduction in obese PCOS than that in obese controls. Thus, the downstream effects of hyperinsulinemia on the somatotropic axis may include up-regulation of hepatic production of GHBP, suppression of IGFBP-1 (r = 0.82) and sex hormone-binding globulin (r = -0.69) levels, and a more than 3-fold increase in ratios of IGF-I/IGFBP-1 and estradiol-testosterone/sex hormone-binding globulin, thereby increasing their bioavailabilities. In contrast, LH pulsatility was unaffected by obesity alone. An accelerated LH pulse frequency was evident in both lean and obese PCOS (P < 0.001), whereas the mean 24-h LH pulse amplitude was increased in lean (P < 0.001), but not obese, PCOS patients. These events resulted in a 3-fold increase in 24-h mean LH levels in lean PCOS and a 2-fold increase in obese PCOS. Thus, increased LH pulse frequency and augmented LH response to GnRH are characteristic of PCOS, independent of obesity, and the presence of obesity in PCOS is associated with an attenuated LH pulse amplitude, not accounted f


Subject(s)
Insulin/blood , Luteinizing Hormone/blood , Obesity/blood , Obesity/complications , Polycystic Ovary Syndrome/blood , Polycystic Ovary Syndrome/complications , Adolescent , Adult , Blood Glucose/analysis , Body Mass Index , Circadian Rhythm , Female , Gonadal Steroid Hormones/blood , Humans , Insulin-Like Growth Factor Binding Proteins/blood , Obesity/pathology , Pulsatile Flow , Reference Values
5.
Hum Reprod ; 11(2): 334-5, 1996 Feb.
Article in English | MEDLINE | ID: mdl-8671220

ABSTRACT

By using aspiration from the vas deferens, apparently good quality spermatozoa can be obtained for in-vitro fertilization (IVF) in cases of non-treatable anejaculation. Being squeezed from the epididymis during aspiration, the spermatozoa may be immature and their fertilizing capacity lower than that of ejaculated spermatozoa. Our case report describes a couple who achieved pregnancy when intracytoplasmic sperm injection (ICSI) was carried out with frozen-thawed spermatozoa aspirated from the vas deferens of a man whose anejaculation was associated with diabetes mellitus. In the aspiration, 50 x 10(6) spermatozoa were obtained. One half of them was frozen, and the other half was used fresh for conventional IVF, resulting in total fertilization failure of all the oocytes. The second treatment was ICSI, in which eight out of 11 oocytes injected with frozen-thawed spermatozoa showed normal fertilization. The second frozen embryo transfer resulted in a normal pregnancy.


Subject(s)
Cytoplasm , Diabetes Mellitus/physiopathology , Ejaculation , Reproductive Techniques , Spermatozoa , Suction , Vas Deferens , Adult , Female , Fertilization in Vitro , Freezing , Humans , Injections , Male , Pregnancy
6.
J Clin Endocrinol Metab ; 80(10): 2966-73, 1995 Oct.
Article in English | MEDLINE | ID: mdl-7559882

ABSTRACT

Recently, we reported that hyperandrogenism in adolescent girls is accompanied by augmented LH pulsatility and elevated LH/FSH ratio with increased ovarian volume. Together with higher concentrations of 17-hydroxyprogesterone, androstenedione, testosterone, and estrone that are ovarian in origin, these neuroendocrine features are identical to those seen in adult women with polycystic ovary syndrome. In the present study, we report the metabolic characteristics of these hyperandrogenic adolescent girls. The GH insulin-like growth factor I (IGF-I)-binding protein (BP)-3 axis, insulin sensitivity, and insulin-IGFBP-1/insulin sex hormone binding globulin axes were evaluated in 13 adolescent girls (ages 11-18 yr) with mild to moderate signs of hyperandrogenism (HA) and 28 age-matched normal girls. Insulin sensitivity was assessed by a frequent-sample iv glucose tolerance test (ivGTT, 0.3 g/kg). Twenty-four hour blood samples were obtained at 10-min intervals and were used to determine GH pulsatility (20-min samples), IGFBP-3 levels (0800-0900 h), and fluctuations of insulin, IGFBP-1, and IGF-I (hourly samples) during feeding and fasting phases of the day. In addition, GH responses to GHRH stimulation (1 microgram/kg) were assessed. Fasting insulin concentrations, but not plasma glucose levels, were significantly elevated in the HA group compared with those in the normal group (256 +/- 35 vs. 103 +/- 24 pmol/L, P = 0.0008), as were insulin responses to ivGTT and meals (P < 0.01) and 24-h mean insulin concentrations (P < 0.01). Thus, hyperinsulinemia with normal fasting glucose levels in HA girls may reflect insulin resistance, as suggested by the increased ratio of insulin and glucose (P < 0.001). All measures of insulin were correlated with body mass index (BMI); however, insulin remained significantly higher in the HA group after correcting for BMI, suggesting that decreased insulin sensitivity was related to other factors in addition to BMI. Twenty-four hour IGFBP-1 concentrations showed a diurnal pattern with an inverse relationship to insulin, and 24-h mean concentrations were lower in the HA group (0.35 +/- 0.13 vs. 0.76 +/- 0.09 micrograms/L, P = 0.02). Reduced sex hormone binding globulin levels were also inversely related to insulin levels (P = 0.0007). In contrast, GH pulsatile characteristics and IGF-I/IGFBP-3 levels, as well as GH responses to GHRH, were similar between the groups.(ABSTRACT TRUNCATED AT 400 WORDS)


Subject(s)
Androgens/blood , Polycystic Ovary Syndrome/metabolism , 17-alpha-Hydroxyprogesterone , Adolescent , Adult , Androstenedione/blood , Blood Glucose/metabolism , Child , Estrone/blood , Female , Follicle Stimulating Hormone/blood , Glucose Tolerance Test , Growth Hormone/blood , Growth Hormone/metabolism , Hirsutism , Humans , Hydroxyprogesterones/blood , Insulin/blood , Insulin-Like Growth Factor Binding Protein 1/blood , Luteinizing Hormone/blood , Luteinizing Hormone/metabolism , Menarche , Menstruation , Oligomenorrhea , Ovary/physiopathology , Polycystic Ovary Syndrome/blood , Polycystic Ovary Syndrome/physiopathology , Regression Analysis , Sex Hormone-Binding Globulin/analysis , Testosterone/blood
7.
Fertil Steril ; 63(6): 1200-3, 1995 Jun.
Article in English | MEDLINE | ID: mdl-7750589

ABSTRACT

OBJECTIVES: To evaluate the effect of clomiphene citrate (CC) on circulating levels of insulin-like growth factor I (IGF-I) and sex hormone-binding globulin (SHBG) in patients with polycystic ovary syndrome (PCOS). DESIGN: Prospective open trial. PATIENTS: Eight women with clinical and biochemical evidence of PCOS. INTERVENTION: One hundred fifty milligrams CC was administered orally for 5 days. MAIN OUTCOME MEASURES: Serum IGF-I, SHBG, LH, FSH, and E2 levels were determined for 8 days, beginning 3 days before CC treatment. RESULTS: A progressive decline in serum IGF-I levels was observed in all subjects reaching a maximum of 30% on the 5th day of therapy (40.6 +/- 5.1 to 28.7 +/- 4.0 nmol/L [conversion factor to SI unit, 0.13]). This was correlated inversely with the expected rises in LH, FSH, and E2 levels. Concomitantly, there was a 23% rise in SHBG levels. The absolute decrease of IGF-I levels was negatively correlated with age and was independent of body mass index. CONCLUSIONS: These observations suggest that oral administration of CC has an impact on the IGF-I and SHBG systems, which may be involved in the initiation of ovulatory function in PCOS.


Subject(s)
Clomiphene/therapeutic use , Insulin-Like Growth Factor I/metabolism , Polycystic Ovary Syndrome/drug therapy , Sex Hormone-Binding Globulin/metabolism , Adolescent , Adult , Case-Control Studies , Clomiphene/pharmacology , Estradiol/blood , Female , Follicle Stimulating Hormone/blood , Humans , Luteinizing Hormone/blood , Polycystic Ovary Syndrome/blood , Prospective Studies
8.
J Soc Gynecol Investig ; 2(1): 38-44, 1995.
Article in English | MEDLINE | ID: mdl-9420847

ABSTRACT

OBJECTIVE: To establish the relation of insulin-like growth factor-I (IGF-I) and IGF-binding protein-1 (IGFBP-1) with 24-hour metabolic excursions in normal healthy women and in response to acute interruption of metabolic homeostasis by hypoinsulinemia. METHODS: Hourly blood samples during the 24-hour metabolic clock were obtained from seven normally cycling women. Uniform dietary composition (50% carbohydrate, 35% fat, and 15% protein) and timing of meals (8 AM, 12 PM, and 6 PM) were prescribed. Daytime hypoinsulinemia was induced by omitting meals and by Sandostatin (100 micrograms) administration. Changes in serum levels of glucose, insulin, cortisol, IGF-I, and IGFBP-1 were measured. RESULTS: The diurnal pattern of serum IGFBP-1 levels during the 24-hour metabolic clock was characterized by a rapid fall during the feeding phase of the day and a progressive 3.5-fold rise during nocturnal fasting; IGF-I levels were unchanged. Changes in IGFBP-1 levels were in parallel to those of cortisol and were inversely related to increases in glucose (80%) and insulin (tenfold) levels after each meal and to their decline during nocturnal fasting. Daytime fasting and administration of Sandostatin were accompanied by rapid and sustained increases in IGFBP-1 when insulin levels declined to 54 +/- 20 pmol/L. CONCLUSIONS: With constant levels of IGF-I, the diurnal rhythm of IGFBP-1 may subserve a physiologic function by coordinating insulin and IGF-I action with substrate availability. Fluctuations of insulin levels during the 24-hour metabolic clock in normal women appear to serve as a signal, with an inhibitory effect on IGFBP-1 production when levels are above 70 pmol/L and a stimulatory effect at levels below 70 pmol/L. These findings provide a basis for future investigations in women with nutritionally related reproductive disorders.


Subject(s)
Circadian Rhythm/physiology , Insulin-Like Growth Factor Binding Protein 1/blood , Insulin/blood , Octreotide/pharmacology , Adult , Blood Glucose/metabolism , Circadian Rhythm/drug effects , Fasting , Female , Hormones/pharmacology , Humans , Insulin/metabolism , Insulin Secretion , Insulin-Like Growth Factor I/metabolism
9.
J Clin Endocrinol Metab ; 79(1): 119-25, 1994 Jul.
Article in English | MEDLINE | ID: mdl-8027216

ABSTRACT

A study was initiated to delineate the neuroendocrine characteristics of hyperandrogenic adolescent girls with the aim of discerning features that may relate to the pubertal onset of the polycystic ovarian syndrome. Thirteen 11- to 18-yr-old girls with mild to moderate signs of hyperandrogenism (HA) and increased ovarian volume and 28 age-matched normal girls were recruited for the study. LH pulsatility and FSH levels were analyzed based on serum concentrations measured with sensitive immunofluorometric assays in samples taken at 10-min intervals for 24 h under basal conditions, GnRH antagonist (Nal-Glu) suppression, and dexamethasone suppression. Adrenal and ovarian contributions to serum cortisol, dehydroepiandrosterone, androstenedione, testosterone (T), estrone (E1), estradiol (hourly), 17-hydroxypregnenolone, and 17-hydroxyprogesterone (17PO) concentrations were compared during basal and suppression conditions and after gonadotropin and adrenal stimulations by bolus GnRH (10 micrograms) and CRF (1 microgram/kg). The progression from sleep-augmented pulsatile LH secretion to higher LH levels during wake than sleep observed during normal pubertal development occurred 2 yr earlier in the HA group. The number of LH pulses was significantly higher in the HA group during both sleep and waking, whereas pulse amplitude was higher only during the awake time. Thus, mean LH was 2.0-fold higher during the awake time and only 1.6-fold higher during sleep in the HA group compared to the normal group. The elevation of FSH in HA was small relative to that of LH, resulting in an increased LH/FSH ratio (P < 0.008). The HA group had higher concentrations of 17PO (1.8-fold), androstenedione (1.9-fold), T (2.4-fold), and E1 (1.7-fold) than the normal group (all P < 0.001), with no alteration in circadian rhythm. These elevated steroid levels were significantly correlated with LH levels in the basal state and decreased in proportion to the change in LH during Nal-Glu suppression. During adrenal suppression with dexamethasone, concentrations of cortisol, dehydroepiandrosterone, and 17-hydroxypregnenolone decreased in both groups (P < 0.001), but significant suppression of 17PO, T, and E1 occurred only in the normal girls, indicating the ovarian origin of the increased levels of these steroids with enhanced expression of 17 alpha-hydroxylase activity in HA girls.(ABSTRACT TRUNCATED AT 400 WORDS)


Subject(s)
Hyperandrogenism/physiopathology , Luteinizing Hormone/metabolism , Ovary/physiopathology , Periodicity , Polycystic Ovary Syndrome/physiopathology , Puberty , Adolescent , Androstenedione/blood , Child , Circadian Rhythm , Dexamethasone , Estrone/blood , Female , Follicle Stimulating Hormone/metabolism , Gonadotropin-Releasing Hormone/analogs & derivatives , Humans , Hyperandrogenism/pathology , Ovary/pathology , Testosterone/blood
10.
Hum Reprod ; 8 Suppl 2: 66-71, 1993 Nov.
Article in English | MEDLINE | ID: mdl-8276972

ABSTRACT

The activity of the gonadotrophin releasing hormone (GnRH) pulse generator during pubertal transition was investigated in 40 healthy girls 7-18 years of age. Ten were pre-pubertal, seven were in early puberty, and 23 were post-menarcheal. Serum concentrations of luteinizing hormone (LH) and follicle stimulating hormone (FSH) were measured with immunofluorimetric assays, which have a sensitivity approximately 100-fold that of radioimmunoassay, in samples taken at 10-min intervals for 24 h during basal conditions, during Nal-Glu antagonist suppression, and in response to GnRH stimulation (10 micrograms). Serum levels of androstenedione, testosterone and oestradiol were measured by radioimmunoassay. Our data show that the GnRH pulse generator is functionally active in prepubertal girls with selective expression of LH and FSH pulses after the onset of sleep. The onset of puberty is associated with a greater increase in LH pulse amplitude than frequency. These overall changes are punctuated by a switch of wake/sleep activities of GnRH pulse generator with a progressive increase in day-time pulsatility and a gradual reduction of sleep-entrained amplification. While LH pulsatility appears to be highly GnRH dependent at all ages, a remarkable decrease in the predominance of GnRH regulation of FSH pulsatility occurs in conjunction with ovarian activation.


Subject(s)
Gonadotropin-Releasing Hormone/metabolism , Puberty/physiology , Adolescent , Child , Female , Fluoroimmunoassay , Follicle Stimulating Hormone/metabolism , Gonadotropin-Releasing Hormone/analogs & derivatives , Gonadotropin-Releasing Hormone/antagonists & inhibitors , Humans , Luteinizing Hormone/metabolism
11.
J Clin Endocrinol Metab ; 76(4): 940-9, 1993 Apr.
Article in English | MEDLINE | ID: mdl-8473410

ABSTRACT

To delineate the activity of the GnRH pulse generator during pubertal transition, 40 healthy girls 7-18 yr of age were studied. Ten were prepubertal (PP), 7 were in early puberty (EP), and 23 were in late puberty (LP, all postmenarcheal). Serum concentrations of LH and FSH were measured with immunofluorometric assays, which have a sensitivity about 100-fold that of RIA, in samples taken at 10-min intervals for 24 h during basal conditions, during Nal-Glu antagonist suppression, and in response to GnRH stimulation (10 micrograms). Serum levels of androstenedione, testosterone, and estradiol were measured with RIA. A pulsatile pattern of LH and FSH secretion was found in girls of all ages. PP girls had irregular LH pulses with low amplitudes during the daytime, but increased amplitude LH and FSH pulses were evident within 1 h after sleep-onset. Older PP girls had more regular and higher amplitude pulses throughout sleep than younger PP girls. The sleep-related LH and FSH pulses in PP girls were abolished with Nal-Glu GnRH antagonist treatment, reflecting endogenous GnRH pulse activities. The PP group had the most pronounced amplification of LH secretion with sleep yielding a sleep-wake ratio of 4, which decreased to 2 in the EP group and to 1 in the LP group. The emergence of regular daytime LH pulses along with a further amplification of pulsatile activity during sleep was closely related to the onset of breast development. By the age of 16 yr, an LH secretory pattern characteristic of adult women in the early follicular phase, i.e. a decrease in LH concentration during sleep, was established. Mean 24-h LH concentrations increased 40-fold from PP to LP consequent to a 9-fold increase in pulse amplitude and a 4-fold increase in pulse number (both P < 0.0001). Mean FSH concentrations (24 h), which were 20-fold higher than corresponding LH concentrations in the PP group, increased only 3-fold from the PP to the LP group. FSH pulse secretion appears to be predominantly GnRH dependent in PP girls in contrast to girls after ovarian activation, as indicated by the increased FSH responses to both GnRH antagonist suppression and GnRH stimulation in the PP as compared to the EP and LP groups. We conclude that the GnRH pulse generator is functionally active in prepubertal girls with selective expression of LH and FSH pulses after the onset of sleep. The onset of puberty is associated with a greater increase in LH pulse amplitude than frequency.(ABSTRACT TRUNCATED AT 400 WORDS)


Subject(s)
Circadian Rhythm , Follicle Stimulating Hormone/blood , Gonadotropin-Releasing Hormone/metabolism , Luteinizing Hormone/blood , Puberty/metabolism , Adolescent , Child , Female , Fluoroimmunoassay , Forecasting , Gonadal Steroid Hormones/blood , Gonadotropin-Releasing Hormone/analogs & derivatives , Gonadotropin-Releasing Hormone/antagonists & inhibitors , Gonadotropin-Releasing Hormone/pharmacology , Humans , Pulsatile Flow
SELECTION OF CITATIONS
SEARCH DETAIL
...