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L Devoto

Publications and source records attributed to L Devoto.

At least 55 records · Page 3Linked to original sources
PubMed1992

In vitro effect of hCG on steroidogenesis in the testicular tissue from a patient with complete androgen resistance.

The present study was performed to determine the in vitro steroidogenic capacity of a gonadal sample from a patient suffering from a complete androgen resistance syndrome. Testosterone and estradiol production by the testicular tissue from this patient as well as gonadotropin binding to a membrane fraction prepared from this tissue were measured. hCG bound with high affinity but with a very low capacity and the gonadotropin induced a clear dose response for both testosterone and estradiol production. The ED50 of hCG on testosterone and estradiol production were 2.5 and 5.0 nM, respectively. We conclude that estradiol originates from Leydig cell activity, since estradiol synthesis does not depend on testosterone availability and it shows a clear hCG dose response.

Adolescent↗
PubMed1992

[Ovulation induction by the chronic administration of naltrexone in a patient with secondary hypothalamic amenorrhea].

An ovulatory cycle was induced by oral administration of a specific opiate antagonist: naltrexone, at a dose of 50 mg/day for 26 days in a woman suffering from secondary hypothalamic amenorrhea. The follicular growth was monitored by ultrasound and serial blood measurement of LH, FSH, E2 and progesterone. The hormonal and ultrasound profiles showed an ovulatory cycle with a single dominant follicle. After discontinuation of the treatment, the patient became amenorrheic again. The gonadotropin as well as estradiol plasma levels declined, to that observed before treatment. Naltrexone may be a useful agent for induction of ovulation in women suffering from hypothalamic amenorrhea.

Adolescent↗
PubMed1991

Effect of the aromatase inhibitor 4-hydroxyandrostene-3,17-dione progesterone synthesis by human luteal cells.

The authors studied the effects of 4-hydroxyandrostene-3,17-dione (4-OHA) on progesterone (P), 17 beta-estradiol (E2), and 20 alpha-hydroxy-4-pregnen-3-one synthesis and pregnenolone accumulation in cultured human midluteal cells. A dose-dependent inhibition with and without human chorionic gonadotropin (hCG) of E2 and P production was observed. The accumulation of pregnenolone was significantly enhanced three to fourfold by 4-OHA in this culture system, as compared with control value. In addition, a sevenfold increase on pregnenolone accumulation was observed in the presence of 4-OHA plus 10 IU of hCG as compared with control values and 2.2-fold as compared with the 4-OHA treatments. These in vitro findings indicate a direct effect of 4-OHA on luteal steroidogenesis. Nevertheless, the suppressive effect of 4-OHA on P and E2 production is located at different sites of the steroidogenic pathway. In addition, the results demonstrate that hCG in the presence of 4-OHA stimulated pregnenolone accumulation, suggesting that the inhibition of P synthesis is in some steps after the formation of pregnenolone. These data indicate that the actions of 4-OHA on P or E2 formation have different inhibitory mechanisms.

20-alpha-Dihydroprogesterone↗
PubMed1991

[Effect of microsurgical resection of the ovary on fertility in patients with polycystic ovary resistant to clomiphene citrate].

Thirteen patients with clomiphene citrate resistant polycystic ovary syndrome (PCO-CR) were documented by clinical and endocrine profile. Exogenous gonadotropins (HMG, hFSH, hCG), or gonadotrophin releasing hormone agonist (GnRHa) plus gonadotropins represent a new approach to induce ovulation in these (PCO-CR) patients. 92% of these patients ovulated with exogenous gonadotropin, nevertheless the pregnancy rate was only 53%. Five out seven PCO-RC patients did not achieve pregnancy with exogenous gonadotrophins, but they did after ovarian wedge resection. It is interesting to note that four of these patients achieved their second and third pregnancy without any therapy. The authors conclude that the ovarian wedge resection may had to improve in the quality of ovulation in this very selective group of infertile patients.

Adult↗
PubMed1990

Pulsatile luteinizing hormone secretion in women with polycystic ovary syndrome under clomiphene citrate. Differences between responders and nonresponders.

Although administration of Clomiphene Citrate (CC) is an effective therapy for ovulation induction in PCO patients, 15 to 20% of PCO patients do not ovulate following CC treatment. The aim of this study was to compare the endocrine dynamics (LH pulsatile pattern, FSH and steroid hormone changes) in 6 patients who ovulated (PCOS) and 6 PCO patients who did not ovulate in response to CC (PCOR). Blood was collected at 15 min intervals for 4 hr on day 9 of the first menstrual cycle (control cycle) and on day 9 of the following (treatment) cycle. In this cycle all women received 100 mg CC/day from day 5 to day 9. LH was determined in all samples whereas FSH and estradiol were measured every 60 min. No significant differences were observed regarding the age, body mass index, degree of hirsutism, ovarian volumes and basal levels of reproductive hormones between both groups of PCO women. During the control cycle, the LH pulse amplitude and transverse LH mean concentrations in PCOR patients were higher than in PCOR patients whereas the LH pulse frequency was similar in both groups. No difference was found in FSH and estradiol values between both groups. Compared to the control cycle, PCOR patients showed no change in the pulse amplitudes and no difference in LH, FSH and estradiol values following CC treatment. In contrast, during the CC therapy in PCOS patients an increase in the LH amplitude (p less than 0.05), the transverse mean LH concentration (p less than 0.05), FSH and estradiol was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Regulation of steroid hormone synthesis by human corpora lutea: failure of follicle-stimulating hormone to support steroidogenesis in vivo and in vitro.

The authors studied the role of follicle-stimulating hormone (FSH) in luteal steroidogenesis by replacing gonadotropin-releasing hormone (GnRH) infusion with pure FSH 48 hours after ovulation in two hypogonadotropic patients. Plasma progesterone (P) and estradiol (E2) decreased after FSH administration. Human luteal cells were cultured for 48 hours in the presence and absence of FSH, human chorionic gonadotropin (hCG), testosterone (T), or dibutyryl cyclic adenosine monophosphate (Bu2cAMP). In the presence of T, E2 synthesis increased significantly, indicating an active aromatase system in these cells. Human chorionic gonadotropin as well as Bu2cAMP significantly increased E2, T, and P synthesis. Follicle-stimulating hormone did not stimulate luteal E2, T, or P synthesis. The authors conclude that FSH does not sustain luteal steroidogenesis. Moreover, the in vitro findings reveal that hCG modulation of luteal E2 synthesis is mediated principally by an increase in androgen precursors. These in vivo and in vitro results confirm a crucial role for luteinizing hormone (LH) in the maintenance of luteal steroidogenesis.

Adult↗
PubMed1989

[Plasma estradiol levels as a predictive prognostic in the early pregnancy].

The authors studied the plasma estradiol (E2) levels as a predictive outcome of the early pregnancy. Weekly determinations of E2 levels were performed in 82 pregnant women during the first 10 weeks of pregnancy. Comparison between E2 levels were performed in the same patients by studying the slope of E2 profile. This slope was studied in 24 normal women during the first weeks of pregnancy (control group). The other 58 pregnant women were recluted from our infertility clinic. 14 of these pregnancy aborted (17%). The slope of the E2 curve in the aborted patients were significantly different than in the control group during the time studied (p 0.001). A positive increase in the slope of the E2 profile has predictive value of 91% in the outcome of normal early pregnancy. Nevertheless only a 66% predictive value was observed in the case of negative increase in the slope of the E2 curve.

Abortion, Spontaneous↗
PubMed1987

In vitro net progesterone production by human corpora lutea: effects of human chorionic gonadotropin, dibutyryl adenosine 3',5'-monophosphate, cholera toxin, and forskolin.

Slices of human corpora lutea (CL) obtained at varying stages of the luteal phase from 21 women were used to study the effect of hCG on progesterone (P4) production. Slices obtained from mid- and late CL incubated with 10 IU/mL hCG exhibited a significant increase in net P4 production (P less than 0.001), whereas slices from early CL did not. Mid-CL slices were the most sensitive to hCG (4.2-fold increase in P4 production compared to 1.2-fold for early CL and 2.7-fold for late CL). To investigate the unresponsiveness of early CL to hCG, [125I]hCG binding was studied. All early CL had LH/hCG-specific receptors, and the apparent Kd for this binding was 1.95 X 10(-10) M. Dibutyryl cAMP (1 mM), cholera toxin (0.84 mM), and forskolin (50 microM) stimulated net P4 production (P less than 0.05) in slices of early CL tissue incubated in the presence of methylisobutylxanthine (0.1 mM). Cholera toxin and forskolin stimulated cAMP formation by the early CL, but hCG failed to do so. These results confirm that hCG has an age-dependent stimulatory effect on CL P4 synthesis. Our findings suggest that there is inadequate coupling of the LH/hCG receptor and adenylate cyclase in the early human CL, which explains in part the relative insensitivity of this tissue to the steroidogenic action of hCG.

Adult↗
PubMed1984

Changes during the menstrual cycle in cytosolic and nuclear concentrations of progestagen receptor in the human Fallopian tube.

[3H]R5020 was bound to cytosolic and nuclear samples of human Fallopian tube with high affinity and specificity. The cytoplasmic and nuclear concentrations of progestagen receptor varied, throughout the menstrual cycle, in the ampulla, isthmus and fimbria. Concentrations were higher at the late proliferative stage of the cycle than at the early proliferative and late secretory stages. A positive linear regression was observed between cytosolic and nuclear progestagen receptor concentrations and plasma oestradiol levels. A negative linear relationship was observed between cytosolic progestagen receptor concentration and plasma progesterone levels during the secretory stages of the menstrual cycle.

Cell Nucleus↗
PubMed1984

Estradiol and progesterone nuclear and cytosol receptors of hydrosalpinx.

Hydrosalpinx is usually associated with a low intrauterine pregnancy rate following restoration of tubal patency by microsurgery. The biochemical evaluation of pathologic tubes from 11 infertile patients showed the presence of estradiol (E2) and progesterone (P) receptors at the cytosol and nuclear levels. The binding constants (Kd) for these specific proteins for E2 and Promegestone (R5020) were of the same magnitude as observed in normal tissue. Mean levels of E2 cytosolic and nuclear receptors and cytosolic P receptors of hydrosalpinx were significantly lower than those of a normal fallopian tube (P less than 0.05). No correlation between the severity of the histologic appearance of the tissue and the subcellular distribution of receptors was observed. We conclude that the decrease in the steroid receptor population of these damaged tubes could be counted as another factor to be considered in the poor intrauterine rate of the salpingoneostomy.

Adult↗
PubMed1982

Changes in cytosolic and nuclear estradiol receptors of normal Fallopian tube throughout the menstrual cycle.

During the normal menstrual cycle, the changes in estradiol binding to cytosol and nuclear receptors of ampulla, isthmus and fimbria were analyzed. Cytosol estradiol receptor concentration showed little variation throughout the cycle, but were higher at the periovulatory phases. The concentration of nuclear estradiol receptor markedly varied in isthmus and ampulla; being significantly higher at the late proliferative phase than at the secretory phases. A positive linear correlation between nuclear receptor content and plasma estradiol concentration was observed, while a negative one was found with plasma progesterone.

Adult↗