Evidence for a role for the neurosteroid allopregnanolone in the modulation of reproductive function in female rats

The present study investigated the effect of allopregnanolone (5 alpha-pregnan-3 alpha-ol-20-one) or of passive immunoneutralization of brain allopregnanolone, the most potent steroid produced by neurons, on ovulation rate and sexual behavior in female rats. Allopregnanolone was injected intracerebroventricularly in rats on diestrus and proestrus and tests were done on estrus. The intracerebroventricular injection of allopregnanolone significantly decreased the number of oocytes collected on estrus (p < 0.01). To support a physiological involvement, antiserum to allopregnanolone was injected centrally to block the activity of the endogenous neurosteroid. When administered on diestrus and proestrus or only on proestrus, the antiserum was shown to be correlated with a significant increase (p < 0.01) in oocytes retrieved on estrus. In female rats treated with antiserum to allopregnanolone, the lordosis intensity was augmented significantly as compared to controls. Finally, the possible changes of medial basal hypothalamus concentration of allopregnanolone throughout the estrous cycle and at the time of ovulation were investigated. Hypothalamic extracts were eluted on high-pressure liquid chromatography and allopregnanolone concentration was measured by radioimmunoassay. Brain cortex was used as control tissue. Hypothalamic allopregnanolone concentration on proestrus morning and afternoon was found to be significantly lower than in the remaining phases of the estrous cycle (p < 0.01), while no significant changes were observed in brain cortex concentration of allopregnanolone. The present results suggest that hypothalamic allopregnanolone may be involved in the mechanism of ovulation, affecting hormonal and behavioral events.

Preoperative serum intercellular adhesion molecule-1 (ICAM-1) and E-selectin (endothelial cell leukocyte adhesion molecule, ELAM-1) in patients with epithelial ovarian cancer

The serum levels of intercellular adhesion molecule-1 (ICAM-1) and E-Selectin (endothelial cell leukocyte adhesion molecule, ELAM-1) were retrospectively measured in serum samples drawn at diagnosis from 66 patients with epithelial ovarian cancer and 128 patients with benign ovarian masses. The preoperative serum ICAM-1 levels were higher in the former group (p < 0.0001), while serum E-Selectin concentrations were similar in the two groups (p = NS). Among patients with epithelial ovarian cancer, neither serum ICAM-1 nor E-selectin levels correlated with FIGO stage and with histologic type. The serum assay of ICAM-1 and E-Selectin seems to have limited value in the management of patients with epithelial ovarian cancer.

Effects of a new estrogen/progestin combination in the treatment of postmenopausal syndrome

Postmenopausal women were randomly given either oral calcium (500 mg/day, control group, n = 12) or a combination of estradiol valerate (EV, 2 mg/day for 21 days) with cyproterone acetate (CPA, 1 mg/day in the last 10 days of the treatment cycle, n = 19). EV+CPA reduced (P < 0.01) postmenopausal complaints, inducing regular withdrawal bleeds, with no hysteroscopic or hystologic evidence of endometrial hyperstimulation after 12 months of treatment. In the control group, spine bone mineral density (BMD) and the total body bone mineral (TBBM) decreased (P < 0.01), whereas urinary hydroxyproline excretion (OH-P/Cr), plasma bone Gla Protein (BGP) and lipid profile did not show any significant modification throughout the study. In the EV+CPA group, urinary OHP/Cr and plasma BGP levels decreased (P < 0.01) after 6 and 12 months, whereas both BMD and TBBM showed a small but significant (P < 0.01) increase. In this group, LDL cholesterol significantly (P < 0.01) decreased and HDL levels significantly (P < 0.01) increased after 6 and 12 months. In conclusion, the EV+CPA combination is effective in relieving menopausal symptoms, produces a good cycle control and a favourable lipid profile, preventing postmenopausal bone resorption.

Factors associated with pain complaints in a clinical sample of postmenopausal women

The aims of this study were to evaluate the relationships occurring between pain complaints and postmenopausal status, and to look at the correlation between such complaints and other symptoms commonly related to the climacterium. A clinical sample of 99 consecutive postmenopausal patients requiring medical help were studied: 36 complained of muscle-skeletal pains whereas 33 presented with headache limiting daily activity. Climacteric syndrome, level of distress, coping style and bone mineral density were assessed with appropriate questionnaires and instruments. Neither bone mineral density, nor body mass index nor time since menopause were associated with either headaches or muscle-skeletal pains. According to the logistic regression being younger, being without a job, suffering from insomnia and having a lower ability in self-support by the means of comforting ideas predicts suffering from headache. A high level of distress and an avoidance behavior to problem facing predict the presence of pain complaints. In such cases the ineffectiveness of the coping mechanism (i.e. avoid the problem) could be the reason for the increased level of psychological distress. These findings indicate that complaining of pains or headache is not dependent upon postmenopausal status. Individual coping strategies and their effectiveness seem the main reasons for the presence of disabling musculoskeletal pains or headache.

Modifications in uterine and intraovarian artery impedance in cycles of treatment with exogenous gonadotropins: effects of luteal phase support

OBJECTIVE

To determine the effects of induction of multiple ovulation and of luteal P supplementation on the impedance to blood flow in the uterine and intraovarian arteries during the luteal phase.

DESIGN

A prospective study using transvaginal color flow Doppler imaging.

SETTING

A university-based infertility center.

PATIENTS

Fifty-six women with unexplained or male factor-related infertility undergoing IUI.

INTERVENTIONS

The patients were studied either during spontaneous cycles (n = 16) or in cycles of induction of multiple follicular development with purified FSH (n = 40). In 18 treated cycles, the luteal phase was supplemented with natural P.

MAIN OUTCOME MEASURES

The pulsatility index was recorded from uterine and intraovarian arteries on the day of E2 peak and 5 and 10 days thereafter. On the same days, E2 and P plasma levels were measured by RIA.

RESULTS

The intraovarian pulsatility index was significantly lower in FSH-treated than in spontaneous cycles on the day of E2 peak. Also, the uterine pulsatility index was significantly lower in treated cycles than in spontaneous cycles on the day of E2 peak and 5 days thereafter. In the late luteal phase, P supplementation was correlated with a significant decrease in uterine pulsatility index as compared with both spontaneous cycles and FSH-treated cycles without luteal support.

CONCLUSIONS

Multiple follicular development is associated with a significant reduction in the impedance to perifollicular blood flow. Progesterone, as well as E2, seems able to decrease the impedance to blood flow in uterine arteries in women.

Changes in dopaminergic control of circulating melanocyte-stimulating hormone-related peptides at puberty

Desacetyl alpha-melanocyte-stimulating hormone (MSH) (ACTH 1-13) is the main form of immunoreactive alpha-MSH circulating in human plasma. This study evaluates the possibility that a dopaminergic inhibitory mechanism could be operative during human development. Thus, alpha-MSH and ACTH 1-13 plasma levels were measured after dopaminergic blockade (domperidone (0.3 mg/kg body weight, maximum 10 mg, p.o.) in 13 prepubertal (aged 4.5-12.3 y) and 12 pubertal (aged 10.2-16.9 y) children. Both peptides were measured by RIA after plasma extraction on Sep-pak C-18 cartridges and reverse phase HPLC. The chromatographic profile of alpha-MSH immunoreactivity falls into two main peaks, corresponding to the retention time of alpha-MSH and ACTH 1-13. Moreover, in prepubertal children domperidone induced a significant increase of alpha-MSH from 1.7 (median) to 5.0 pmol/L, whereas no changes in alpha-MSH plasma levels were found in pubertal subjects (from 5.0 to 4.1 pmol/L). Similarly, ACTH 1-13 plasma levels significantly increased from 3.0 to 19.8 pmol/L in prepubertal children remaining stable in pubertal ones (from 7.8 to 4.6 pmol/L). Moreover, a significant negative correlation was found between basal DHEA-S levels and the plasma alpha-MSH increase after domperidone. These data demonstrate that: 1) ACTH 1-13 is the main form of immunoreactive alpha-MSH in prepubertal life and 2) the dopaminergic inhibition of both ACTH 1-13 and alpha-MSH plasma levels is apparent only in prepubertal subjects.

Steroid-protein interaction in human placenta

Human placenta produces a large variety of bioactive substances with endocrine and neural competence: pituitary and gonadal hormones, hypothalamic-like releasing or inhibiting hormones, growth factors, cytokines and neuropeptides. The most recent findings indicate that locally produced hormones regulate the secretion of other placental hormones supporting a paracrine/autocrine regulation. In placental endocrinology, a particular relevance is played by steroid hormones. In fact, a specific gonadotropin-releasing hormone (GnRH)-human chorionic gonadotropin (hCG) regulation of placental steroidogenesis has been proposed as a placental internal regulatory system acting on steroids production from human placenta. In addition, activin and inhibin have been proposed as further regulatory substances of the synthesis and secretion of steroids; the addition of activin A to placental culture augments GnRH, hCG and progesterone, and this effect can be significantly reduced by the addition of inhibins. Finally, a steroid-steroid interaction is suggested by the evidence that placental estrogen has a positive role in the regulation of progesterone biosynthesis. Other steroid-protein interactions have been observed in human placenta. In fact, recent data indicate that progesterone inhibits placental corticotropin-releasing factor (CRF) and estrogens act on placental conversion of cortisol to cortisone, activating cortisol secretion by the fetal adrenal and enhancing fetal adrenal function with advancing gestation.

Prospective evaluation of calcium and estrogen administration on bone mass and metabolism after ovariectomy

We evaluated the effects of low-dose ethinylestradiol administration in the prevention of the rapid bone loss that follows ovariectomy in women. After 10-30 days from surgery, patients received either a sole calcium supplementation 500 mg/day (n = 20) or ethinylestradiol 20 micrograms/day in addition to the same daily calcium supplement (n = 21), for 12 months. In the control group, urinary hydroxyproline excretion, serum alkaline phosphatase and plasma bone Gla protein levels presented a substantial (p < 0.05) increase, while radial bone density significantly (p < 0.05) decreased 6 months after surgery. In the ethinylestradiol-treated group, the patterns of biochemical markers indicated that ethinylestradiol can restrain the bone remodelling processes. Radial bone density showed no significant modification during the 12 months' study period. In conclusions, these results demonstrate that the administration of 20 micrograms/day of ethinylestradiol can prevent the rapid bone loss that follows ovariectomy.

Factors predicting labour onset in patients treated with prostaglandin E2 for cervical ripening

The aim of this study is the evaluation of predictive factors in the onset of labour after pre-induction cervical ripening with prostaglandins. We enrolled 112 consecutive singleton term pregnancies (37-42.3 weeks) with unfavourable cervix and intact membranes, requiring induction of labour because prolonged pregnancy (59%) or maternal/fetal complications (41%). Treatment consisted of the cervical application (once or twice, 12 h apart) of prostaglandin E2 gel (Upjohn, Italy). Uterine activity was monitored by external cardio-tocography before and during the next 2 h. Two patients showed uterine hyperstimulation and acute fetal distress requiring caesarean section. Sixty percent of patients went to labour and delivered without further stimulations. In this group the rate of caesarean section (9.1%) was lower than in patients failing to onset labour (68.2%). According to the logistic regression three factors positively predicted the onset of labour: first-hour uterine contractility, basal uterine activity and gestational age. The first-hour contractility in particular, represents the myometrial sensitivity to prostaglandin E2 and may become a practical marker of spontaneous onset of labour in patients undergoing cervical ripening.

Doppler analysis of uterine blood flow changes in spontaneous and medically induced menopause

The aim of this study was to compare the uterine blood flow variations induced by chemical castration and spontaneous menopause. Thirty infertile patients were studied in the early follicular phase (day 5-7) and then treated with gonadotropin releasing hormone agonists (GnRH-a). On day 25 from GnRH-a injection, the suppressive effect was checked. The values obtained were compared with those found in 18 postmenopausal women (menopause < 5 years). All the subjects underwent transvaginal ultrasonography, Doppler analysis of uterine arteries, hormonal assay and evaluation of hematological and biochemical parameters. In all infertile patients, the GnRH-a suppressive effect was shown at the 25th day from the injection. Endometrium thickness decreased from 0.6 +/- 0.1 mm to 0.3 +/- 0.1 mm (p < 0.05) and the pulsatility index increased from 2.52 +/- 0.31 to 3.02 +/- 0.25 (p < 0.05). The plasma estradiol level fell from 48.2 +/- 4.4 pg/ml to 13.6 +/- 7.9 pg/ml (p < 0.05). No other hormonal and biochemical parameters were significantly modified by GnRH-a. In postmenopausal women, the values of the studied parameters were similar to those found in the infertile GnRH-a-suppressed patients. These data show that GnRH-a induces vascular modifications similar to those induced by early post-menopause and that both are probably exclusively related to hypoestrogenism.

Expression of pro-opiomelanocortin gene in human ovarian tissue

The high concentration of pro-opiomelanocortin (POMC)-derived peptides in human follicular fluid, which is several times higher than in plasma, suggested a local expression of the POMC gene. This has previously been observed in the animal ovaries. Peripheral POMC-like mRNAs are not translated in POMC-derived peptides but recent evidence supports the presence of a small amount of full-length transcript in human testes and lymphocytes. The purpose of this study was to test two hypotheses: firstly, that there is a different pattern of POMC mRNA expression in the human ovary of fertile and post-menopausal women, and secondly that there is a tissue-specific localization of POMC transcript. Northern blot analysis showed that a potential relationship exists between POMC gene expression and the reproductive age of a woman, and that POMC mRNA has a tissue-specific localization. The expression of POMC messenger in the ovarian parenchyma collected from women of fertile age and in the germinative follicles appeared higher than that observed in samples from post-menopausal women. No signals were detected in corpora lutea. In conclusion, we believe that the physiological role of the POMC gene in the human ovary remains an unsolved problem, necessitating more sensitive methods of mRNA detection as well as further studies in vitro.

Uterine artery velocimetry and spontaneous preterm delivery

OBJECTIVE

To evaluate if idiopathic spontaneous preterm delivery is associated with abnormal uteroplacental circulation, as assessed by Doppler velocimetry.

METHODS

The study was carried out on 417 women who had Doppler velocimetry performed between 25-36 weeks' gestation and were subsequently delivered vaginally. The systolic-diastolic ratio (S/D) was computed for the uterine and umbilical arteries, and the outcomes of pregnancies with spontaneous preterm and term deliveries were compared.

RESULTS

Uterine artery S/D was significantly higher (P < .0001) in the 31 patients delivered preterm, whereas no significant difference was observed in the umbilical S/D. Abnormal values of uterine S/D were detected in 58.1% of the preterm group, independent of the gestational age at examination. No significant increase in S/D was observed in patients hospitalized for preterm labor who delivered subsequently at term. Spontaneous preterm delivery was associated with increased uterine S/D among both pregnancies with small for gestational age fetuses and those with appropriately grown fetuses.

CONCLUSION

Preterm delivery is associated with modifications of uterine artery Doppler velocimetry, suggesting that impaired trophoblastic invasion of the placental bed may play a role in determining preterm delivery.

Evidence for a role of neurosteroids in modulation of diurnal changes and acute stress-induced corticosterone secretion in rats

The neurosteroid allopregnanolone has been shown to be a potent ligand of gamma-aminobutyric acid (GABA)-A receptors and enhances its receptor-mediated inhibitory events. Since central GABA plays a major inhibitory role, via GABA-A receptors, in hypothalamic-pituitary-adrenal (HPA) function in rats, the present study has evaluated the effect of passive immunoneutralization of allopregnanolone on diurnal changes in corticosterone secretion and acute stress-induced corticosterone secretion in rats. In the first protocol, four groups of male rats (prepubertal, fertile, castrated adult and aged) and three groups of female rats (prepubertal, fertile at different phases of the estrous cycle and aged) were studied. Rats were injected intracerebroventricularly (i.c.v.) with 10 microliters anti-allopregnanolone serum or 10 microliters normal rabbit serum (control) 24 h before exposure to an acute cold swimming stress, and sacrificed either before stress or after 5 min stress. In the second protocol, fertile male or female rats at diestrus II were injected i.c.v. with anti-allopregnanolone serum or normal rabbit serum and sacrificed on the following day at 10.00 or 18.00. Truncal blood samples were collected for measuring plasma corticosterone. Our results showed that there was no significant difference in basal plasma corticosterone levels between antiserum-treated and control rats of both sexes. However, in male rats, central injection of antiserum to allopregnanolone significantly potentiated plasma corticosterone response to stress in prepubertal and adult fertile rats as well as in castrated rats. Likewise, in female rats, the stress response of plasma corticosterone was enhanced by passive immunoneutralization of allopregnanolone in prepubertal and fertile rats throughout the estrous cycle.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormal concentration of maternal serum activin-A in gestational diseases

Serum plasma activin-A is measurable in the maternal circulation of healthy pregnant women, increases in specimens collected during the third trimester of gestation, and is highest at parturition. Hormone abnormalities are known to be associated with preterm labor or diabetes in pregnancy. Therefore, in the present study serum activin-A levels in normal controls were compared to those in pregnant women with preterm labor or gestational diabetes. In some cases, values were obtained before and after insulin therapy. In other controls and patients with preterm labor, the activin-A concentration in cord serum was also studied. A newly developed two-site immunotest was used to determine activin-A levels. Subjects included normal controls (n = 7), who were sampled throughout gestation every 5 weeks; pregnant women at term (38-40 weeks) not in labor (n = 22); pregnant women at term in spontaneous labor (< 3.0 cm dilated; n = 42); women in preterm labor (25-35 weeks; n = 38); and women with gestational diabetes (20-39 weeks; n = 9). In control women, serum activin-A levels increased from 4.8 +/- 5.5 micrograms/L (mean +/- SD) at 20 weeks to 25.4 +/- 27.8 micrograms/L at 40 weeks (P < 0.01), and values correlated with gestational age. Pregnant women in preterm labor had serum activin-A concentrations (89.04 +/- 173.31 micrograms/L) higher than those in normal controls (P < 0.01), and no significant correlation to gestational age was found in this group of pregnant women. Healthy women in labor showed serum activin-A concentrations higher than those in women at term but not in labor (P < 0.01). Diabetic patients had serum activin-A concentrations (52.39 +/- 23.32 micrograms/L) significantly higher than those in normal controls. In these patients, maternal serum activin-A concentrations significantly decreased to the range in healthy controls at the same gestational age after insulin therapy (9.48 +/- 3.82 micrograms/L). The present study shows that preterm labor is associated with increased concentrations of activin-A in the maternal circulation and cord serum. Hypersecretion of activin-A is also shown in same patients with gestation diabetes; this reverts to normal after insulin treatment.

Treatment of postmenopausal vertebral osteopenia with monofluorophospate: a long-term calcium-controlled study

The aim of the present study was to assess the effects of the new fluorine pro-drug monofluorophosphate (MFP) in postmenopausal women with vertebral osteopenia and high bone turnover. We enrolled postmenopausal women (PMW, 43-59 years) who had had a natural menopause 2-5 years before the study, had vertebral bone mineral density (BMD) < 1 SD from the premenopausal mean, and had at least one of the biochemical markers of bone remodeling > 1 SD over the mean for premenopausal women. Patients were randomly divided into two treatment groups (group 1, 500 mg/day of oral calcium; group 2, MFP at the dose of 20 mg F-equivalents + 600 mg calcium/day) for 2 years (n = 21 in each group). The lumbar vertebral (L2-4) BMD and total body bone mineral (TBBM) were measured by dual-energy X-ray absorptiometry (Lunar DPX, Lunar Corporation, USA). Urinary hydroxyproline excretion (OH-P/Cr), plasma bone Gla protein (BGP) and serum alkaline phosphatase (AP) were assayed. In group 1 the markers of bone turnover and vertebral BMD did not show any significant modification, while TBBM showed a significant (p < 0.05) decrease after 24 months. In group 2 a significant (p < 0.05) decrease in OH-P/Cr (-23.9 +/- 2.0%), and an increase in both BGP (+19.4 +/- 2.6%) and AP (+10.3 +/- 2.6%) levels were observed after 24 months of MFP administration. In this group, both vertebral BMD (+5.01 +/- 0.9%, p < 0.01) and TBBM (+4.0 +/- 0.6%, p < 0.05) showed a significant increase after 24 months. Present results suggest that, in osteopenic PMW, MFP administration induces a significant increase in vertebral BMD without impairment of cortical bone, with a reduction in bone resorption and an increase in bone formation rate.

The role of color Doppler imaging in the diagnosis of polycystic ovary syndrome

OBJECTIVE

Our purpose was to evaluate whether intraovarian and uterine blood flow variations are associated with clinical, ultrasonographic, and endocrine polycystic ovary syndrome findings.

STUDY DESIGN

Thirty-two hirsute, oligomenorrheic patients and 18 volunteer women underwent in the early follicular phase ultrasonographic evaluation of ovarian volume, echodensity, and follicle number; transvaginal color Doppler measurement of the uterine and intraovarian vessel variations; and radioimmunologic dosage of luteinizing hormone, follicle-stimulating hormone, estradiol, progesterone, testosterone, androstenedione, and other hormonal compartments.

RESULTS

In the patients with polycystic ovary syndrome (increased luteinizing hormone/follicle-stimulating hormone ratio, elevated androstenedione levels, high number of subcapsular follicles by ultrasonography-augmented ovarian volume and echodensity) (n = 22) we observed, at Doppler analysis, significantly elevated uterine artery pulsatility index values associated with a typical low resistance index of stromal ovary vascularization. The pulsatility index was positively correlated with the luteinizing hormone/follicle-stimulating hormone ratio, and the resistance index was negatively correlated. The elevated uterine artery resistance was correlated with androstenedione levels.

CONCLUSION

Doppler analysis can be a valuable additional tool for the diagnosis of polycystic ovary syndrome.

A comparative, randomized study of three different progesterone support of the luteal phase following IVF/ET program

The use of luteal phase support has been demonstrated in patients undergoing IVF/ET in cycles stimulated after pituitary desensitization with gonadotrophin releasing hormone agonists. However, it is still not clear which is the most suitable kind of supplementation. This study was designed to compare the absorption and the efficacy of three different luteal support. We randomly administered progesterone i.m. (50 mg/day), human chorionic gonadotrophin (hCG) (2000 IU every three days), progesterone vaginal cream (100 mg/day) or nothing (controls) to 176 women treated for assisted procreation. We were not able to show any statistical differences for the percentage of pregnancy rate between groups. The serum progesterone (P) and 17-beta-estradiol (E2) and E2/P ratio levels of the luteal phase were compared with the control not supplemented group. All the treatments were able to increase significantly the luteal P values versus controls (p < 0.01). Moreover, vaginal cream and natural P im significantly decreased E2/P ratio (p < 0.05). Serum P levels were more steady with P vaginal cream than im injection. Vaginal cream for better bioavailability and acceptance appear the most suitable and comfortable method for luteal phase support.

Involvement of mu-opioid receptors in the modulation of pituitary-adrenal axis in normal and stressed rats

The availability of the most selective, high-affinity, natural opioid agonists for mu-receptors (dermorphin-DM) and delta-receptors (deltorphin-DT) has provided the possibility for in vivo studying of the role of acute and chronic activation of mu- and delta-opioid receptors on the functional activity of the hypothalamus-pituitary-adrenocortical (HPA) axis, both in basal conditions and in response to an acute stress in adult male rats. Plasma corticosterone (CS) and beta-endorphin-like-immunoreactivity (beta-EP-LI) levels were measured by specific radioimmunoassays before and after 5 and 30 minutes from the exposure to cold (3 +/- 0.5 C) water and forcing them to swim for 10 minutes (acute cold swimming stress). Acute administration of DM, the specific mu-receptor agonist, enhanced basal and stress induced plasma levels of CS and beta-EP-LI. These effects were antagonized by pretreatment with naloxone, specific mu-opioid receptor antagonist, but not by naltrindole, a delta-opioid receptor antagonist. Long-term administration of DM did not alter resting plasma levels of CS and beta-EP-LI, but significantly reduced stress-induced increase of these hormones. Both the acute and chronic administration of the DT, highly selective delta-opioid receptors agonist, failed to modify resting and stress induced hormone levels. Our present data show that DM throughout mu-opioid receptors, but not DT, modulates the response of HPA axis to acute stress in rats, increasing or decreasing the release of CS and beta-EP-LI when acutely or chronically administered, respectively.

Pituitary and ovarian interleukin-1 alpha content changes according to estrous cycle and acute stress exposure

A complex interaction between the immune and neuroendocrine systems has been established. In particular, cytokines are known to be one of the mediators of the stress response, and modulate hormone secretion by acting in the brain, pituitary and gonads. The aim of the present study is to investigate whether pituitary and ovarian interleukin-1 alpha (IL-1 alpha) content changes according to the estrous cycle. In addition, the possible pituitary and ovarian IL-1 alpha changes in rats exposed to acute (5 min) or chronic intermittent (twice a day for 4 days) cold swimming stress were studied. The IL-1 alpha content of ovarian and pituitary homogenates was measured by a sensitive and specific radioimmunoassay. Immunoreactive IL-1 alpha (irIL-1 alpha) was detectable only in ovaries collected in rats at proestrus and estrus while not in those collected at diestrus I and II. The highest values were found at proestrus. No significant changes were found in ovarian irIL-1 alpha content in rats exposed to acute or chronic intermittent stress in comparison to control rats. In the pituitary, no difference in IL-1 alpha content was found throughout the estrous cycle. Acute stress induced a significant increase in pituitary irIL-1 alpha content only at proestrus (p < 0.01), however, no significant differences were found in comparison to control rats after chronic intermittent stress. The proestrus-related changes of ovarian IL-1 alpha may constitute a hormone-dependent signal within the ovary that is involved in the ovulatory process.(ABSTRACT TRUNCATED AT 250 WORDS)

Opioid peptides and testicular activity in the lizard Podarcis s. sicula Raf

In mammals endorphinergic systems have been shown to modulate reproductive processes and beta-endorphin (beta-EP) has been found to influence sexual functions, acting at the hypothalamus-pituitary-gonadal axis level. Using immunocytochemical and in vitro studies, evidence for a diffuse pro-opiomelanocortin-related opioid system in the lizard Podarcis s. sicula was produced. In the testis, beta-EP immunoreactivity showed seasonal variation, being most pronounced in the interstitial cells of sexually quiescent lizards (December). Reverse-phase high-performance liquid chromatography, coupled with radioimmunoassay and immunocytochemistry, showed that beta-EP and acetyl beta-EP increased during December, while their concentrations were low during April, when the highest testicular activity occurred. Using in vivo studies, it was found that naltrexone treatment, blocking pituitary opioid receptor, increased androgen levels in the plasma and in the testis. It was also found with in vitro studies that the endogenous opioid system inhibits gonadotrophin release and therefore androgen production by the testis. The data reported here provide evidence for the physiological role played by opioid peptides at the pituitary level to regulate the seasonal reproductive activity of the lizard Podarcis s. sicula.

Acute stress- or lipopolysaccharide-induced corticosterone secretion in female rats is independent of the oestrous cycle

The aim of the present study was to test whether oestrous cycle is associated with the hypothalamus-pituitary-adrenal (HPA) axis function. Thus, corticosterone secretion in rats was investigated following lipopolysaccharide (LPS), acute cold-swimming or ether stress or synthetic corticotrophin-releasing factor (CRF) administration throughout the oestrous cycle. Moreover, plasma corticosterone response to cold-swimming stress or LPS administration also was studied at different times of day on pro-oestrus of di-oestrus-I. The following observations were obtained: the morning plasma corticosterone levels in control rats did not differ with the stage of the oestrous cycle; plasma corticosterone levels increased significantly following LPS administration (2 mg/kg, ip) or following acute exposure to cold (4 degrees C)-swimming or ether stress. However, this increase in plasma corticosterone levels was not related to the stage of the oestrous cycle; synthetic CRF injection induced an increase in plasma corticosterone levels constant on di-oestrus-I and pro-oestrus; plasma corticosterone response to LPS administration or acute cold-swimming stress showed diurnal changes, with the lowest values at 18.00 h, which was independent of the oestrous cycle. By showing the unchanged corticosterone response to LPS, to acute stress and to exogenous CRF throughout the oestrous cycle, and the independence of the diurnal pattern of stress response on the oestrous cycle, the present study suggests that the oestrous cycle has no influence on the HPA activity under the present experimental conditions in rats.

Maternal hyperoxygenation in the treatment of mild intrauterine growth retardation: a pilot study

The aim of this study was to determine the efficacy of long-term maternal hyperoxygenation in comparison with bed rest in the management of mildly growth-retarded fetuses (5-10th centile).Thirty-eight patients with intrauterine growth retardation were studied. The patients were divided into oxygen-treated (n = 18) and untreated (n = 20) groups. Ultrasound assessment of amniotic fluid volume was performed on alternate days, and the fetal abdominal circumference was evaluated weekly. Doppler analysis of fetal/maternal circulation was performed upon the patient's arrival at hospital, after 12 h, and thereafter on alternate days until parturition. Fetal blood was sampled by cordocentesis for immediate blood gas analysis at the start of the study and on the day of delivery. Although in the treated patients there was significant improvement in Doppler flow pat tern and blood gas indices, no significant differences in type of delivery and perinatal outcome were noted between the groups. Maternal hyperoxygenation in mild intrauterine growth retardation did not improve perinatal outcome.

Evidence suggesting an additional control mechanism regulating episodic secretion of luteinizing hormone and follicle stimulating hormone in pre-pubertal children and post-menopausal women

The possible differential regulation of pulsatile follicle stimulating hormone (FSH) and luteinizing hormone (LH) secretion in pre-pubertal children and in post-menopausal women was investigated. Children were studied for 4 h and post-menopausal women for 6 h; blood samples were taken every 10 min. Post-menopausal women were studied before and 21 days after administration of a single i.m. dose of gonadotrophin-releasing hormone (GnRH) analogue. Eight post-menopausal women and 18 children (nine boys and nine girls) were enrolled. The children were divided into two groups: A, at Tanner stages 0-1 (four boys and three girls); B, at Tanner stage 2-3 (five boys and six girls). Plasma LH and FSH concentrations were determined using an immunofluorimetric assay. Time series were analysed and the specific concordance (SC) index was computed to determine the degree of concordance between episodes of LH and FSH secretion. While children of group A had LH concentrations below the minimal detectable dose of 0.1 IU/l, group B showed measurable LH plasma concentrations (1.4 +/- 0.3 IU/l, mean +/- SEM). Plasma FSH concentrations were detectable in both groups. Group A showed FSH plasma concentrations significantly lower than those of group B (0.75 +/- 0.2 and 1.95 +/- 0.4 IU/l respectively; P < 0.05), but FSH pulse frequency was higher in group A (P < 0.05). Children of group B showed significant concomitance of LH and FSH secretory events at time 0 (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Ontogeny of the circadian rhythm in medial basal hypothalamic beta-endorphin content in female rat

The present study evaluated the possible role of estrogens in generating the circadian rhythm of medial basal hypothalamus content at the time of puberty in female rats. Accordingly, changes in medial basal hypothalamus beta-endorphin (beta-EP) content were investigated in female rats, before and at puberty. Groups of intact or ovariectomized rats were studied after estradiol-benzoate or placebo treatment. The results showed that circadian rhythm of beta-EP content of medial basal hypothalamus is absent in prepubertal rats, while it appears at puberty, associated to a significant increase of beta-EP concentration. The primary involvement of steroids in generating this circadian rhythm was supported by the finding that estradiol-benzoate treatment caused a precocious appearance of beta-EP hypothalamic diurnal changes in prepubertal rats. Moreover, estradiol-benzoate replacement restored the loss of beta-EP nocturnal increase induced by ovariectomy in pubertal animals. Therefore, these data support the significant role of estrogen in inducing the circadian rhythm of beta-EP content in medial basal hypothalamus at the time of puberty in female rats.