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Biomedical subjects

E Porcu

Publications and source records attributed to E Porcu.

At least 73 records · Page 4Linked to original sources
PubMed1988

Episodic pulsatile secretion of FSH, LH, prolactin, oestradiol, oestrone, and LH circadian variations in polycystic ovary syndrome.

Pulsatile secretion of LH, FSH, PRL, oestradiol and oestrone was studied in a group of 16 patients with micropolycystic ovary syndrome (PCOS) and compared with that of normal ovulatory women in the fifth to sixth day of the cycle. Hormone concentrations were measured at 10 min intervals for 8 h starting at 0930 h. In seven subjects, the study was prolonged for 24 h, with 20 min interval samples, in an attempt to evaluate the circadian rhythm of LH by cosinor analysis. Significant fluctuations occurred in the concentration of each hormone. Values shown are mean +/- SD. PCOS subjects had high LH mean values (27.9 +/- 5.9 IU/l) (P less than 0.005). LH pulse amplitude was higher than controls (11.6 +/- 3.7 IU/l versus 5.2 +/- 1.8 IU/l; P less than 0.005) while no consistent changes in frequency or interpulse interval (62.0 +/- 10.7 min versus 65.8 +/- 19.2 min; P = NS) were found. A mean of 4.8 +/- 1.2 pulses of FSH occurred in 8 h and the mean pulse amplitude was 2.68 +/- 1.11 with no differences from controls. All patients were normoprolactinaemic. A mean of 5.5 +/- 1.9 pulses occurred in 8 h, the interpulse interval was 76.1 +/- 14.4 min and the amplitude was 2.87 +/- 0.76 ng/ml and there were no significant differences from controls; 75% of PRL pulses showed a temporal relationship with LH pulses. Oestrone mean basal values were higher in PCOS (47.2 +/- 12.5 pg/ml) than controls (32.0 +/- 9.9 pg/ml; P less than 0.02), while no differences were observed as regards oestradiol. Oestradiol pulse amplitude was nearly the same as oestrone (43.6 +/- 18.8 pg/ml and 37.7 +/- 16.1 pg/ml, respectively); 6.0 +/- 2.2 pulses and 6.0 +/- 1.6 pulses occurred in 8 h with an interpulse interval of 81.1 +/- 27.1 min and 71.8 +/- 11.1 min, respectively. Sixty-five per cent of LH pulses were followed by an oestradiol and oestrone peak. The mean time of the appearance was 17 +/- 15 min and 25 +/- 23 min, respectively. In the PCOS group a consistent 24 h rhythm in mean plasma LH levels was found with the highest hormone values at 1720 h (P less than 0.05) unrelated to apparent sleep and different from that of adult women. Pulse frequency showed a significant slowing during the night with the longest interpulse interval at 0327 h (P less than 0.03) while no significant periodicity was observed in LH pulse amplitude.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1988

Evidence for a hypothalamic alteration of catecholamine metabolism in polycystic ovary syndrome.

The role of brain catecholamine (CA) activity in the neuroendocrine regulation of the GnRH-LH system in polycystic ovary syndrome (PCO) was investigated by high-performance liquid chromatography (HPLC) with electrochemical detector. We measured urinary dopamine (DA), noradrenaline (NA), adrenaline (A), vanillylmandelic acid (VMA), homovanillic acid (HVA), 3,4-dihydroxyphenylacetic acid (DOPAC) and total 3-methoxy-4-hydroxyphenylglycol (MHPG) levels in a group of 12 women with PCO before and during peripheral dopa-decarboxylase blockade, by carbidopa. HVA and DOPAC concentrations were significantly lower (P less than 0.001 and P less than 0.005, respectively) in PCO patients compared with twelve control subjects in early follicular phase, whereas total MHPG concentrations and MHPG/VMA ratio were significantly higher (P less than 0.005) in PCO patients. Moreover, HVA and DOPAC concentrations in PCO patients were similar to those of the control subjects in preovulatory phase, while MHPG concentrations remained higher in PCO patients (P less than 0.01). DA, NA, A and VMA concentrations were similar to those of control subjects in both phases of the cycle. During carbidopa administration the concentrations of all urinary CAs and metabolites were unchanged, except those of DA which dropped markedly (P less than 0.001). These data suggest that (1) an altered central catecholamine metabolism consisting of DA deficiency and NA excess is present in PCO, and (2) the site of DA deficiency may be located in the hypothalamus.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1987

Postmenarchal evolution of endocrine pattern and ovarian aspects in adolescents with menstrual irregularities.

Ninety-five adolescents with menstrual irregularities persisting since menarche were studied and the data analyzed in relation to gynecologic age. In each year, in the premenstrual phase, luteinizing hormone (LH), testosterone (T), and androstenedione (delta 4A) values were higher than those of adults. Estrone (E1), estradiol (E2), 17-hydroxyprogesterone (17-OHP), progesterone (P), and dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) gradually increased up to adult values correlating with gynecologic age. By ultrasound, nearly half the ovaries were multicystic and ovarian volume was greater than that of adults in each gynecologic year. When the data were classified as ovulatory or anovulatory, ovulation appeared to be a dynamic process characterized by ovaries similar to those of adults and by increasing hormonal levels correlated to gynecologic age. By contrast, in anovulatory cycles, mean T, delta 4A, and LH values were stable in each year and constantly higher than in ovulatory cycles and adult controls. These findings suggest that, despite persistent irregular cycles, some adolescents normalize all endocrine and ovarian parameters toward maturity, while subjects with persistent irregular anovulatory cycles maintain marked hyperandrogenism, increasingly high LH values, and enlarged multicystic ovaries.

Adolescent↗
PubMed1987

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.

Adolescent↗
PubMed1987

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.

Adolescent↗
PubMed1987

Effects of alpha 1-adrenergic blockade on pulsatile luteinizing hormone, follicle-stimulating hormone, and prolactin secretion in polycystic ovary syndrome.

Central noradrenergic mechanisms may participate in the regulation of pulsatile gonadotropin secretion in women with the polycystic ovary syndrome (PCO). To examine this possibility we measured serum LH, FSH, and PRL concentrations at 10-min intervals and total testosterone and 17 beta-estradiol at 60-min intervals for 8 h basally and during the infusion of the alpha 1-adrenoceptor antagonist thymoxamine (10 micrograms/kg X min) in 10 young women with PCO. Mean and integrated serum LH concentrations as well as LH pulse frequency were not significantly altered (P = NS) during the thymoxamine infusion. However, we found an increase in LH pulse amplitude as both net (P less than 0.002) and percent (P less than 0.002) increment, as well as mean LH peak values (P less than 0.05) during alpha 1-adrenergic blockade. There were no significant changes in pulsatile FSH and PRL secretion or gonadal sex steroids during these experimental conditions. These data suggest that in PCO patients, 1) brain noradrenergic mechanisms do not play a stimulatory role in regulating the frequency of pulsatile LH secretion, 2) central noradrenergic activity inhibits LH pulse amplitude, and 3) PRL and FSH pulsatility are not altered by central noradrenergic blockade.

Adolescent↗
PubMed1987

Evidence for a physiological reduction in brain dopamine but not norepinephrine metabolism during the preovulatory phase in normal women.

To investigate the role of brain catecholamine (CA) activity in the mechanisms related to physiological ovulatory function, we used high-performance liquid chromatography with electrochemical detector to measure the levels of urinary dopamine (DA), norepinephrine (NE), epinephrine (E), vanillylmandelic acid (VMA), homovanillic acid (HVA), 3,4-dihydroxyphenylacetic acid (DOPAC), and total 3-methoxy-4-hydroxy-phenylglycol (MHPG) in a group of 12 normal women during both the early follicular and pre-ovulatory phases of the menstrual cycle. The mean (+/- SEM) concentrations of HVA and DOPAC were significantly lower (P less than 0.001) during the pre-ovulatory phase than during the early follicular phase, whereas those of DA, NE, E, VMA and total MHPG were unaltered. A significant negative correlation between urinary HVA and plasma LH (r = -0.70, P less than 0.01) was also found during the pre-ovulatory period, whereas no significant negative correlations were found between urinary HVA and plasma PRL, progesterone and oestradiol. These data show: 1) reduced brain DA activity and 2) unchanged brain NE activity at the time of the midcycle surge in normal women, suggesting a physiological variation of the central DA metabolism in ovulatory function.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1986

Effects of obesity on gonadotropin secretion in patients with polycystic ovarian disease.

To investigate the interrelationships between body weight and gonadotropin secretion of polycystic ovarian disease (PCO), basal hormonal pattern and responses of gonadotropins and 17 beta estradiol (E2) to 25 micrograms (bolus) and 175 micrograms (4-h infusion) of synthetic luteinizing hormone-releasing hormone (LHRH) were studied in two age-matched groups of 18 obese (OB-PCO) and 18 normal-weight (NO-PCO) women suffering from the syndrome. Unlike other hormone levels, plasma LH and the LH/FSH ratio values were significantly higher (p less than 0.001) in NO-PCO than in OB-PCO females. Moreover, LH response to both stimuli was significantly greater in NO-PCO with respect to OB-PCO. No differences were found in FSH response, whereas E2 response was significantly higher (p less than 0.05) in the NO-PCO group during the continuous infusion test. These results emphasize the role of body weight in the development of PCO in obese females.

Adolescent↗
PubMed1986

Human urinary follicle-stimulating hormone and human menopausal gonadotropin in induction of multiple follicle growth and ovulation.

Five normally menstruating women were treated, in an attempt to induce development of multiple follicles, with pharmacologic doses of purified human urinary follicle-stimulating hormone (hU-FSH) and (in another instance) with human menopausal gonadotropin (hMG) administered on the second and third days after the onset of menses. All of the cycles were ovulatory: the follicular phase was short and the luteal phase length was normal in both hMG and hU-FSH treatment. No substantial differences were seen between the two types of treatment in regard to plasma values of FSH, luteinizing hormone (LH), estradiol (E2), testosterone, and progesterone (P). FSH, E2, and P increased to supraphysiologic levels, and LH fluctuated within the normal range. On ultrasound examination, a large number of growing and matured follicles were visualized during both treatments: at human chorionic gonadotropin administration, multiple preovulatory follicles (greater than or equal to 15 mm) and only a few small follicles (less than 10 mm) were imaged, without any difference between the two types of treatment. Multiple corpora lutea were often obtained. These data underline that pharmacologic doses of FSH alone are able to induce the growth of multiple preovulatory follicles when the initiation of stimulation is timed early. Besides this, exogenous LH does not seem to interfere with follicular recruitment, and it is not required for follicular maturation and ovarian steroidogenesis when endogenous normal LH mean values are present.

Adult↗
PubMed1986

Menstrual irregularities in adolescents: hormonal pattern and ovarian morphology.

The endocrine pattern and ovarian characteristics of 110 healthy adolescents with menstrual irregularities were investigated during the early follicular and premenstrual phases and were compared to those of 14 adolescents with regular menstrual cycles and 20 adults. Over a period of six gynecological years a low ovulation rate (49%) was found in the group of subjects with irregular cycles and regular ovulation was noted in only a few subjects. Slight differences in endocrine pattern and ovarian morphology were observed between the group of adolescents with regular cycles and the group of adults. In contrast, adolescents with irregular menses had higher mean values of luteinizing hormone (LH), testosterone (T), and androstenedione (A) in comparison with the other two groups both in follicular and premenstrual phases. Nearly 35% of the subjects with irregular cycles had levels of T, A and LH which were higher than the upper limit of the adult normal range. Lower progesterone (P), 17P and oestradiol values were observed in the premenstrual phase. Within the group of subjects with irregular menses, LH levels were higher in anovulatory than in ovulatory cycles, in both phases of the cycle, while T and A levels were higher and prolactin levels were lower in the premenstrual phase of anovulatory cycles. Unlike irregular anovulatory cycles, irregular ovulatory cycles showed a hormonal pattern similar to that found in the adult group. By ultrasound evaluation, a high percentage of subjects with irregular menses had multicystic ovaries (57.9%) and the mean (+/- SEM) ovarian volume was higher (10.6 +/- 0.5 cm3) than that found in adolescents with regular menses (6.7 +/- 0.8 cm3) and in the adult group (7.7 +/- 0.3 cm3). With the increase in frequency and continuity of ovulation an improvement in the direction of adult volume and ovarian structure was observed. Besides the endocrine similarity the data emphasize the striking similarity, already documented by histological studies, between pubertal ovaries and those seen in micropolycystic ovary syndrome. These endocrine and ovarian characteristics are typical of a large number of adolescents with irregular menstrual cycles: these features may be representative of a developmental step toward adult normality, although the possibility of a pathological evolution for some subjects cannot be excluded.

Adolescent↗
PubMed1986

Ovarian multifollicularity, high LH and androgen plasma levels, and anovulation are frequent and strongly linked in adolescent irregular cycles.

Ninety-seven adolescents (0.5-6.0 years in gynaecological age) suffering from various kinds of menstrual irregularities were studied and compared with 20 adults by performing ovarian ultrasonography and plasma hormonal determinations. High percentages of multifollicularity (57.7%) and enlarged ovaries (46.3%) were found in the entire group of adolescents. Adolescents with multifollicular ovaries (more than 4 cystic areas) showed higher percentages of luteinizing hormone (LH: 32%), testosterone (T: 34%), and androstenedione (A: 43%) levels exceeding the upper normal adult range than subjects with homogeneous (less than 4 cystic areas) ovaries (LH: 12%, T: 10%, A: 19%, respectively). Ovulation can further discriminate the adolescents: in fact, adolescents with homogeneous ovaries and ovulatory cycles have a hormonal pattern almost identical to that of adults. On the contrary, subjects with multifollicular ovaries and anovulatory cycles show low values of follicle-stimulating hormone (FSH) and high values of LH, T and A, significantly different from those in ovulatory subjects with homogeneous ovaries (P less than 0.005) and from those in adults (P less than 0.005).

Adolescent↗
PubMed1985

Ultrasound study of ovarian and uterine morphology in women with polycystic ovary syndrome before, during and after treatment with cyproterone acetate and ethinyloestradiol.

Women with the polycystic ovary syndrome were treated cyclically for two years with an oral oestrogen/progestogen combination of 50 mg of cyproterone acetate and 0.05 mg of ethinyloestradiol. Ovarian volume, ovarian texture and uterine size were monitored by ultrasound before, during and after treatment. Menstrual rhythm, ovulation and the degree of hirsutism were also studied clinically. A significant decrease in the ovarian volume and in the number of cystic areas was observed during treatment. Hirsutism was also markedly improved. Some of these beneficial effects persisted after treatment was stopped. The number of subjects who had regular, ovulatory cycles increased after stopping treatment. Growth of uterine muscle occurred during treatment.

Adolescent↗
PubMed1985

Naloxone does not interfere with the dopamine-induced decrease in gonadotropin secretion in women with polycystic ovarian disease.

Dopamine infusion 4 micrograms/kg/min over 4 h, administered to six subjects with diagnosis of polycystic ovarian disease laparoscopically confirmed, produced a significant decrease in serum LH, FSH and PRL, suggesting a reduced dopamine activity in these subjects. The addition of naloxone 4 mg iv bolus plus 4 mg/h over 2 h, a specific opiate antagonist, does not interfere with the well-established dopaminergic inhibitory influence on LH, FSH and PRL secretion. This suggests that opiatergic pathways are not directly involved in the dopamine-induced suppressive effect on LH secretion in subjects with LH-dependent polycystic ovarian disease.

Adult↗
PubMed1985

Use of human urinary follicle-stimulating hormone in infertile women with polycystic ovaries.

Human urinary FSH (HU-FSH) was administered during 25 treatment cycles to 21 infertile women with polycystic ovary syndrome (PCO) who had failed to conceive in response to clomiphene citrate. HCG was also given in 23 of the cycles. Twenty-two (88%) ovulations occurred, and eight (38.1%) conceptions resulted, two (25%) of which terminated in abortion and six (75.0%) in normal deliveries. No multiple pregnancies occurred. Ten instances (40%) of mild-moderate hyperstimulation also resulted. A spontaneous LH surge was observed in 12 treatment cycles. Ultrasound scanning revealed multiple ovarian follicles developing at various rates. We conclude that HU-FSH is an effective form of treatment for women with PCO. However, the response to exogenous FSH is unpredictable and depends on the stage of development and the number of follicles present prior to stimulation.

Chorionic Gonadotropin↗
PubMed1984

Comparison between human urinary follicle-stimulating hormone and human menopausal gonadotropin treatment in polycystic ovary.

Five infertile patients with polycystic ovarian disease were treated to induce ovulation with pure human urinary follicle-stimulating hormone and human menopausal gonadotropin consisting of follicle-stimulating hormone and luteinizing hormone in 1:1 ratio. No substantial differences were seen between the two types of treatment regarding plasma values of follicle-stimulating hormone, prolactin, testosterone, dihydrotestosterone, progesterone, and 17-hydroxyprogesterone. Estrone, estradiol, and androstenedione values were higher during human urinary follicle-stimulating hormone treatments. Luteinizing hormone levels dropped in both treatments, but the fall was greater during human urinary follicle-stimulating hormone. No real differences were observed concerning number of ovulations, length of treatments, and follicle-stimulating hormone amounts administered; no hyperstimulations were observed. These data do not confirm the observation that more controlled responses of the ovaries can be elicited when low luteinizing hormone gonadotropin preparations are used.

Androgens↗
PubMed1983

Ultrasound study of ovarian morphology in women with polycystic ovary syndrome before and during treatment with an oestrogen/progestogen preparation.

Women with polycystic ovarian disease were treated with oral estrogens and progestogens and their ovarian volume, ovarian texture and uterine size were studied by ultrasound before and during treatment. A significant decrease in the volume and in the number of follicles in the ovaries was seen. Hormone therapy thus temporarily restores normal ovarian morphology in subjects with polycystic ovaries. The uterus did not change significantly during treatment.

Cyproterone↗
PubMed1983

Induction of ovulation with human urinary follicle-stimulating hormone: endocrine pattern and ultrasound monitoring.

Nine infertile patients, suffering from polycystic ovaries, were treated with human urinary FSH and hCG (eight cases) to induce ovulation. Oestrone, oestradiol, 17 alpha-hydroxyprogesterone, testosterone and androstenedione serum levels increased during the treatment. A decrease in luteinizing hormone serum levels was noticed, and in five cases a spontaneous peak was observed. No changes were noted in 5 alpha-dihydrotestosterone serum levels. Ultrasound scanning of the ovaries often revealed multiple follicles at different speeds and stages of growth and their marked turnover was observed. The beginning of the LH spontaneous surge was precocious compared to the normal ovulating follicular sizes: it does not appear that an optimum size exists but when the LH peak occurred too prematurely, ovulation did not take place. Administration of hCG seems to be necessary as spontaneous peaks of LH are not always followed by rupture of the follicle. Ultrasound scanning plays an important role in monitoring ovulation induction, while oestradiol and 17 alpha-hydroxyprogesterone serum levels are not good indicators of follicular maturity in multifollicular growth. Ovulation occurred in eight patients; four conceptions were obtained, one of which resulted in abortion. No ovarian hyperstimulations were observed.

Adolescent↗