Chronic neonatal NMDA blockade results in long-term cholinergic increase in the rat spinal cord

Rat pups were treated daily with increasing doses of the competitive N-methyl-D-aspartate (NMDA) antagonist CGP 39551 from postnatal day 1 to 22. Normal rats, as well as rats kept undernourished to the same extent as CGP 39551-treated animals were raised in parallel. The neonatal treatment resulted in significant increase of choline acetyltransferase (+14%) in the adult spinal cord. High affinity glutamate uptake was increased to a similar magnitude in treated rats, but the same effect was also noticed for neonatally undernourished rats. No alteration of other neurochemical markers was observed. The present results add new evidence to a developmental role mediated by NMDA receptors and extend to the spinal cord the value of models of chronic neonatal block of this receptor.

Decreased excitotoxic sensitivity in the olfactory cortex of adult rats after neonatal NMDA blockade

Neonatal rats were daily treated with increasing doses of the competitive NMDA antagonist CGP 39551 from postnatal day 1 to 22. At 75-80 days of age the rats were given an excitotoxic dose of kainic acid s.c. Histological examination suggested that the olfactory cortex of the neonatally CGP 39551-treated rats was less damaged than that of controls. This was quantitatively confirmed by assaying the decrease of appropriate neurochemical markers (D-[3H]aspartate uptake and glutamate decarboxylase) as an index of the extent of neuronal degeneration. By contrast, the decrease of the same markers was not different in the hippocampus. These results suggest a selective effect on some brain circuits of adult rats consequent to the neonatal blockade of NMDA receptors and, therefore, add new evidence to a developmental role of this receptor.

Immunocytochemical evidence for the presence of Met-enkephalin and Leu-enkephalin in distinct neurons in the brain of the elasmobranch fish Scyliorhinus canicula

Immunohistochemical methods have been used to investigate the distribution of various opioid peptides derived from mammalian proenkephalin in the central nervous system of Scyliorhinus canicula. The results indicate that both Leu- and Met-enkephalin-immunoreactive peptides are present in the dogfish brain. In contrast, enkephalin forms similar to Met-enkephalin-Arg-Phe or Met-enkephalin-Arg-Gly-Leu, and mammalian alpha-neo-endorphin, dynorphin A (1-8), dynorphin A (1-13), and dynorphin A (1-17) were not detected. Met- and Leu-enkephalin immunoreactivities were found in distinct neurons of the telencephalon and hypothalamus. In particular, cell bodies reacting only with the Met-enkephalin antiserum were localized in the preoptic nucleus and in the suprachiasmatic region of the hypothalamus. Conversely, cell bodies reacting only with the Leu-enkephalin antiserum were localized in the pallium and the nucleus lobi lateralis hypothalami. Several areas of the telencephalon and diencephalon exhibited both Met- and Leu-enkephalin-like immunoreactivity, but the two immunoreactive peptides were clearly contained in distinct perikarya. The overall distribution of Met-enkephalin-immunoreactive elements in the dogfish exhibited similarities to the distribution of proenkephalin-derived peptides previously reported for the brain of tetrapods. The fact that Met- and Leu-enkephalin-like peptides were detected in distinct neurons, together with the absence of dynorphin-related peptides, suggests the existence of a novel Leu-enkephalin-containing precursor in the dogfish brain.

Changes of opioid modulation of the hypothalamo-pituitary-adrenal axis in patients with severe premenstrual syndrome

To assess the function of the hypothalamus-pituitary-adrenal axis in patients with severe premenstrual syndrome (PMS) 28 patients and 14 asymptomatic controls were studied during the mid- to late-luteal phase of the menstrual cycle. The response of plasma cortisol to both high-dose naloxone and corticotropin-releasing hormone (CRH) was assessed. Naloxone stimulated a significant cortisol release in controls whereas it was otherwise almost absent in patients. CRH stimulated a greater release of cortisol in patients than in controls. Fifteen patients met criteria for either current anxiety and/or mood disorders. The cortisol secretion after both naloxone and CRH stimulations was similar for PMS patients with or without psychiatric disorders. These data indicate that endogenous opioids modulate the activity of the hypothalamus-pituitary-adrenal axis. Irrespective of the concomitant presence of menstrual migraine or psychiatric disorder, such control is altered in patients with severe PMS because of the possible hyposensitivity of opiate receptors. The hyperresponsiveness to CRH may be the consequence of the reduced inhibition that endogenous opioids tonically exert on HPA axis.

Pleural effusion in sarcoidosis: a case report

Pleural effusion is a well-recognized clinical entity that can be associated with sarcoidosis. Nevertheless, the real prevalence of this phenomenon remains to be established. This study describes the case of a 57-year-old male sarcoid patient who presented with right exudative pleural effusion, dyspnea on exertion, and bilateral pulmonary interstitial infiltrates. Sarcoidosis was diagnosed more than 2 years prior to the onset of pleural involvement. Pleural biopsy revealed the presence of typical sarcoid non caseating granulomas. Sarcoid involvement of the pleura resolved following a 1-month course of high doses of steroids and did not recur during a 18-month follow up. When we retrospectively analyzed clinical data obtained from 624 consecutive sarcoid patients who were referred to our hospital between January 1980 and June 1993 and examined for the presence of pleural involvement, the only patient who showed pleural effusion and histologically proven sarcoidosis of the pleura was the case here described. The frequency of the phenomenon in our series is 0.16%. We conclude that pleural effusion represents a rare event in sarcoidosis.

Life events impact in patients with secondary amenorrhoea

To evaluate the relationship between stressful life events and the onset of secondary amenorrhoea Paykel's semi-structured interview for Recent Life Events was administered to patients affected by secondary amenorrhea and also to healthy volunteers. The number, quality, and objective negative impact of life events were compared among different hormonal subtypes of secondary amenorrhoea and healthy normally menstruating women, as a control group. The number of life events in amenorrhoeic patients (N = 131) was significantly greater than those observed in the control group (N = 64) (45.9 vs 32.8%). Moreover, where only hypothalamic hypogonadotrophic amenorrhoea was considered, the occurrence of life events was significantly higher (59.8%) than in hyperandrogenic (26.6%) or in normogonadotrophic (20.4%) patients. The most prevalent events among hypothalamic hypogonadotrophic amenorrhoeic patients were those classified as 'undesirable', 'uncontrolled' and with 'Objective Negative Impact'. The present study supports the hypothesis of a cause-effect relationship between stressful personal life events and the onset of secondary amenorrhoea of hypogonadotrophic subtype.

Chronic neonatal blockade of NMDA receptor does not affect developmental polyamine metabolism but results in altered response to the excitotoxic induction of ornithine decarboxylase

Neonatal rats were subjected to chronic blockade of the N-methyl-D-aspartate (NMDA) receptor through daily systemic administration of increasing doses of the competitive antagonist CGP 39551 from postnatal days 1-22. Treatment did not result in any significant alteration of the levels of putrescine, spermidine and spermine or in the constitutively expressed activity of the key enzyme for polyamine biosynthesis, ornithine decarboxylase (ODC), as evaluated at 10 and 20 days of age. However, in 30-day-old rats significant differences were observed in the process of excitotoxic ODC induction in the olfactory cortex and the hippocampus of chronically-treated rats: the increase of ODC activity caused by systemic administration of kainic acid took place more rapidly but it was shorter and apparently reached a smaller peak in treated animals as compared to controls. This result, in conjunction with previous data on neurochemistry and locomotor activity of similarly treated rats, strengthens the suggestion that functional alterations of some brain circuits may be the consequence of the blockade of NMDA receptor during the critical neonatal period of brain maturation.

Opioid peptide modulation of stress-induced plasma steroid changes in the frog Rana esculenta

The present paper aims to evaluate whether a neuroendocrine system including opioids accounts for the effects of stress in the frog, Rana esculenta. Using an acute-stress paradigm, the involvement of hypothalamic opioid peptides was investigated biochemically as well as by in vivo studies. HPLC and RIA investigations confirm the presence of beta-endorphin-like peptides in the brain of this frog. Several immunoreactive peaks are present, two of them coeluting with beta-endorphin and acetyl beta-endorphin reference peptides. Quantitative evaluation revealed that the beta-EP content of 24-hr captured animals was higher than that in fresh captured ones. The stress paradigm applied here was consistent with the measurement of plasma androgens and corticosterone levels in females after short-captivity confinement. In comparison with fresh-captured animals, a sharp decrease of these levels was found within 10-24 hr after capture. These effects were reversed by naltrexone, a long-acting opioid antagonist, after 24 hr of treatment. In fact, in the captive animals injected with 100 ng of naltrexone, the plasma androgen titers remained low at the 10th hour postcapture, but rose to the control levels within 24 hr. A similar effect was found for the plasma corticosterone levels. These data demonstrate that, in this anuran, endogenous opioids could mediate the stress-induced inhibition of gonadal function, and perhaps the inhibition of the hypothalamus-pituitary-adrenal axis.

Presence and steroidogenetic activity of beta-endorphin in the ovary of the lizard, Podarcis s. sicula raf

In mammals, proopiomelanocortin (POMC)-related peptides are involved in reproductive processes at both the hypothalamopituitary and ovarian levels. Through immunocytochemical and physiological in vitro studies, evidence for a diffuse POMC-related opioid system in the lizard Podarcis s. sicula is provided. In the lizard ovary, beta-endorphin (beta-EP)-like immunoreactive cells were observed within the granulosa layer; the immunoresponse showed seasonal variation, being most pronounced in the winter ovary. HPLC followed by immunoassay showed that acetyl beta-EP is the main form of POMC-related peptide in both pituitary and ovary. In vitro studies showed that picomolar amounts of beta-EP stimulate follicular estrogen production during both the reproductive and winter phases; induction was found to be higher in the reproductive phase. The data reported here provide evidence for the physiological role played by beta-EP in the reproductive function of Podarcis s. sicula via induction of ovarian production of estradiol-17 beta, which is the main factor responsible for the vitellogenic process.

Long-lasting effects of chronic neonatal blockade of N-methyl-D-aspartate receptor through the competitive antagonist CGP 39551 in rats

A competitive antagonist of the N-methyl-D-aspartate receptor, CGP 39551, was administered daily to neonatal rats with increasing doses from postnatal day 1 to 22. These animals displayed approximately 50% decrease of body weight at the end of treatment and, therefore, both normal and neonatally undernourished rats were used as controls. At a young adult stage (55-75 days of age) CGP 39551-treated rats showed a much higher spontaneous locomotor activity as compared to control groups. This hypermotility was counteracted by D1 and D2 dopamine antagonists while administration of methamphetamine increased, to the same extent, the differential basal locomotor activity of treated and control groups. The locomotor activity response to the N-methyl-D-aspartate channel blocker, dizocilpine maleate, was significantly shifted to the right for treated rats so that an equivalent increase of motility was obtained by doubling the dose effective for control animals. In in vivo microdialysis experiments, similar amounts of dopamine were collected from the striatum of treated and control rats after high K+ or methamphetamine stimulation, the only difference being a greater Ca2+ dependency of the depolarization-induced dopamine release in treated rats. Assays for different neurochemical parameters, carried out at 80-90 days of age, suggested some alteration of the balance between excitatory and inhibitory circuits in the basal ganglia of CGP 39551-treated rats. Tyrosine hydroxylase and calbindin immunostaining, as well as acetylcholinesterase histochemistry, revealed a similar picture in the striatum of treated and control rats. However, 5'-nucleotidase histochemistry showed a stronger and evenly distributed reactivity in the striatum of treated rats, opposite to the weaker and patchy localization of normal or undernourished controls. From the present results it is possible to conclude that chronic blockade of the N-methyl-D-aspartate receptor during neonatal brain maturation results in long-lasting alteration of locomotor activity which appears related to functional changes of the dopamine receptors as well as to an altered balance between various excitatory and inhibitory neurotransmitter and neuromodulatory systems.

The neuroendocrine effects of sumatriptan, a specific ligand for 5-HT1-like receptors

OBJECTIVE

A relationship between the serotoninergic and the opiatergic system in the pathogenesis of head pain is supported by several data. This study was carried out to investigate the neuroendocrine effects of sumatriptan, a specific serotonin agonist used in the treatment of migraine, on hypothalamic-pituitary-adrenal axis (PHA) hormones.

DESIGN

Two consecutive studies were performed. In study A, eight subjects received a subcutaneous (s.c.) injection of sumatriptan (6 mg). In study B, a further six subjects were randomized to receive either sumatriptan or placebo.

SUBJECTS

Healthy volunteers recruited within the staff (eight males and six females) were studied.

MEASUREMENT

In study A, plasma cortisol and PRL were measured by direct RIA and beta-endorphin after extraction and chromatography. Samples were collected from 60 minutes before to 120 minutes after the administration of the drug, at 15-minute intervals. According to the data of the first study, in study B, in addition to cortisol and beta-endorphin, ACTH was also measured.

RESULTS

Significant increases in the mean beta-endorphin and cortisol concentrations were found in every subject receiving sumatriptan, while no significant changes were observed in prolactin plasma levels. Study B confirmed the activation of the pituitary-adrenal axis, additionally demonstrating the release of ACTH, and indicated that placebo has no effects.

CONCLUSION

Acute s.c. stimulation with sumatriptan activates the pituitary-adrenal axis.

Impaired neurogenesis by methylazoxymethanol in newborn rats results in transient reduction of ornithine decarboxylase and polyamines in the cerebellum, but not in the olfactory bulbs

Polyamines and the key enzyme for their biosynthesis, ornithine decarboxylase (ODC) play an important role in the control of neuronal proliferation and differentiation. Exposure to agents that interfere with normal cell maturation is expected to result in alteration of neuronal ODC developmental pattern. We have administered to newborn rats, about 6 and 30 hr after birth, 20 mg/kg of methylazoxymethanol acetate (MAM), an agent able to selectively kill dividing cells and we have evaluated ODC activity and polyamine levels in the cerebellum and ODC activity in the olfactory bulbs at various developmental stages starting from postnatal day 4 (PD 4) until PD 28. Cerebellar weight decreased by 22-50% at the different developmental stages in MAM-treated animals. A decline in ODC specific activity was observed at PD 4 and a decrease of putrescine levels at PD 4 and PD 6 in the cerebellum. At PD 10, however, both ODC activity and putrescine level were increased in MAM-treated animals. Spermidine levels were never affected by the treatment, while spermine was significantly decreased at PD 6 and PD 8. These results demonstrate that altered ontogenetic patterns of ODC activity and polyamine levels are the consequence of disturbance of the normal process of brain maturation. No significant differences in specific ODC activity were noticed in the olfactory bulbs of MAM-treated rats. This may be related to the more widespread time-span of neurogenesis in this region, a fact that is also revealed by the higher ODC activity constitutively expressed at times in which neurogenesis has ended in the rest of the brain.

Ovarian melanotropic peptides and adaptation in two teleostean species: Sparus aurata L. and Dicentrarchus labrax L

The ovarian tissue of Dicentrarchus labrax and Sparus aurata displays two immunoreactive peaks that correspond to the elution time of human des-acetyl alpha-MSH [ACTH(1-13)-amide] and human alpha-MSH. In view of the close identity between the primary structure of fish and human alpha-MSH, these data demonstrate that two MSH-related peptides are present both in sea bream and sea bass ovary. alpha-MSH-like immunoreactivity was found within both granulosa and thecal layers of mature follicles, as well as in the cytoplasm of oogonia of sea bream and sea bass ovary. Gonadal content of ACTH(1-13)-amide and alpha-MSH display differences with regard to season, showing the highest peptide levels in reproductive animals. Moreover, the alpha-MSH content is significantly higher in the ovary of fish farm animals, whereas that of ACTH(1-13)-amide prevails in wild fish ovary.

Menstrual-related mood changes in patients with oligomenorrhea

In order to evaluate the role of negative anticipation on self-report of premenstrual symptoms, we studied 13 oligomenorrheic and 12 control women with regular menses. Both hormonal and psychological measures (using the Symptom Rating Test) were obtained once a week for 5-9 weeks. The presence of ovulatory cycles was confirmed by progesterone levels > or = 3.0 ng/ml. In both groups, there was a significant increase in the total Symptom Rating Test score during the premenstrual phase with respect to the intermenstrual period. As far as specific symptoms were concerned, MANOVA showed significant premenstrual fluctuations in anxiety, depression, somatic symptoms, and inadequacy in both groups. These results suggest that premenstrual discomfort may be unrelated to both cycle length and negative anticipation of one's menses.

The association of menstrual migraine with the premenstrual syndrome

To investigate the comorbidity of premenstrual syndrome (PMS) and menstrual migraine, the Menstrual Distress Questionnaire (MDQ) was prospectively administered for two consecutive menstrual cycles to 22 patients with menstrual migraine, 12 cases with migraine without aura and 15 patients with PMS. MDQ scores varied throughout the menstrual cycle in each patient group, the wider changes being shown by patients with PMS. Fourteen menstrual migraine patients and 4 migraine without aura patients achieved diagnostic criteria for PMS over two menstrual cycles. In these patients MDQ scores did not differ from PMS sufferers at any stage of the menstrual cycle. The premenstrual increase of each cluster of PMS symptoms was identical in menstrual migraine and PMS subjects with the exception of negative affect. We suggest that PMS symptoms should be taken into account in the IHS diagnostic criteria for menstrual migraine.

Structural, neurochemical and behavioural consequences of neonatal blockade of NMDA receptor through chronic treatment with CGP 39551 or MK-801

Recent evidence suggests that NMDA receptors may be involved in survival of neurons and establishment of correct connectivity during development. We have treated rat pups from postnatal day 1 to 22 with daily s.c. injections of a competitive (CGP 39551) and a non-competitive (MK-801) antagonist of the NMDA receptor. Body weight of treated rats was decreased by 50-65% at postnatal day 24 and by 25-32% at 70 days of age. Brain weight was decreased by 16-24% at both ages. Among the different brain regions, the cerebellum and striatum appeared more decreased in size than the cortex and hippocampus. Only few minor, and in some cases transient, differences were measured in the cerebellum, the hippocampus and the cortex for a battery of neurochemical markers related to cholinergic, GABAergic and glutamatergic transmission as well as to astrocyte and oligodendrocyte activity. When tested in actometric cages from postnatal days 28 to 60, treated rats exhibited a dramatic increase of spontaneous locomotor activity which was maximal in 28-day-old animals (380% and 250% of control values in CGP 39551 and MK-801 groups, respectively) and was still significant at 60 days of age. Therefore, long-lasting alteration of motor behaviour is obtained by the schedule of chronic treatment adopted for the present experiments. Our results suggest that blockade of NMDA receptors during the critical period of brain maturation may result in permanent alteration of neural circuits.

Characteristics of headache at menopause: a clinico-epidemiologic study

The prevalence and characteristics of primary headaches in a large sample of postmenopausal women were investigated. Seventy-six out of 556 women (13.7%) were affected by headache of either the migraine or tension type. In 82% of cases onset had preceded the menopause. The postmenopausal course of headaches with a premenopausal onset differed according to type of headache and type of menopause. Indeed, while migraine improved in almost two-thirds of cases, tension-type headache worsened or did not change in 70% of cases. However, in women who had undergone surgical ovariectomy, the natural course of migraine was worse than in those who had a physiological menopause (P = 0.003). Among the symptoms covered by the Kuppermann Index, only anxiety and insomnia were correlated with headache. The favourable course of migraine in the postmenopausal period can be attributed primarily to the absence of variations in sex hormone levels although psychological factors also seem to play a fundamental role.

FSH secretory pattern and degree of concordance with LH in amenorrheic, fertile, and postmenopausal women

Pulsatile secretion of gonadotropin was investigated in amenorrheic patients and in fertile and postmenopausal women to assess both follicle-stimulating hormone (FSH) episodic secretion and its temporal coupling with luteinizing hormone (LH). Three groups of amenorrheic patients were studied: hyperandrogenic (n = 20), hypogonadotropic (n = 51), and normogonadotropic (n = 31). Nineteen fertile women (during the follicular and luteal phases of the cycle) and sixteen postmenopausal women were investigated as reference groups. All subjects demonstrated the presence of a distinct pulsatile pattern with LH and FSH pulses/4 h as follows: hyperandrogenic 3.95 +/- 0.26 and 3.85 +/- 0.2, hypogonadotropic 3.76 +/- 0.26 and 3.9 +/- 0.16, normogonadotropic 3.5 +/- 0.2 and 3.9 +/- 0.17 LH and FSH pulses/4 h, respectively (means +/- SE). Normal controls showed 4.1 +/- 0.2 and 3.1 +/- 0.2 pulses/4 h for LH (P < 0.05) and 3.2 +/- 0.1 and 3.6 +/- 0.3 pulses/4 h for FSH, during follicular and luteal phases, respectively. Postmenopausal women showed 3.6 +/- 0.2 and 3.0 +/- 0.3 pulses/4 h for LH and FSH, respectively. Specific concordance (SC) index demonstrated that LH and FSH were significantly and simultaneously secreted in all groups. Conversely, LH and FSH were not temporally related during the luteal phase. In conclusion, we report a distinct FSH episodic secretion and its temporal linkage with LH pulses irrespective of plasma concentrations of gonadal steroids in secondary amenorrhea.

Neuroendocrine changes in luteal function in patients with premenstrual syndrome

The present study evaluates the luteal progesterone (P) and LH secretions in 14 patients affected by premenstrual syndrome (PMS) and in 14 asymptomatic controls through the evaluation of their episodic release. PMS was prospectively confirmed in two consecutive menstrual cycles using Moos' Menstrual Distress Questionnaire. A pulsatility study was performed during the luteal phase. Blood samples were drawn every 10 min for 12 h, beginning at 0800 h. Statistically significant pulses were detected using the Detect program, and the degree of concordance of LH and P pulses was estimated. Similar mean 12-h P levels were found in controls (mean +/- SD, 13.9 +/- 9.3 nmol/L) and patients (14.2 +/- 10.1). LH levels were also similar in the two groups. Patients showed a higher P pulse frequency (13.4 +/- 1.8 vs. 11.4 +/- 2.3; P < 0.02) and a reduced amplitude of secretory episodes (126.5 +/- 61.6% vs. 187.1 +/- 126.7%; P < 0.03) than controls. Similarly, PMS patients showed pulsatile LH release of increased frequency and reduced amplitude than controls. A significant degree of concordance between LH and P pulses was observed in both groups, with a time lag of 0-10 min; that is, P secretory episodes follow LH with a delay of 0-10 min. These findings demonstrate that despite the fact that integrated P levels in PMS patients are similar to those in control subjects, the episodic secretion of the hormone is characterized by pulses of increased frequency and reduced amplitude. This phenomenon is temporally related to LH secretion, thus reinforcing the concept of PMS as a neuroendocrine disorder.

Opioids and testicular activity in the frog, Rana esculenta

The presence and activity of brain, pituitary and testicular beta-endorphin (beta-EP)-like material have been studied in the frog, Rana esculenta, using reverse-phase high-pressure liquid chromatography, coupled with radioimmunoassay and immunocytochemistry. In-vivo and in-vitro treatments with naltrexone were carried out to assess the putative physiological activity of opioid peptides. beta-EP(1-31) and (1-27), together with their acetylated forms, have been identified in brain, pituitary and testis. In particular, beta-EP(1-31) concentrations peaked during July in the brain and pituitary, whilst in testes maximum concentrations were found in April and November. beta-EP immunoreactivity was present in the brain within the nucleus preopticus and nucleus infundibularis ventralis while positive fibres in the retrochiasmatic regions projected to the median eminence. In the testis, interstitial cells, canaliculi of the efferent system, spermatogonia and spermatocytes showed positive immunostaining for beta-EP. In intact animals, naltrexone treatment increased plasma and testicular androgen levels and this effect was confirmed in in-vitro incubations of minced testes. Naltrexone also induced a significant increase in germ cell degeneration. Our results indicated that an opioid system modulates the hypothalamus-pituitary-gonadal axis in the frog, Rana esculenta and, for the first time, we have shown that the testicular activity of a non-mammalian species may be regulated by opiates locally.

Immune and neuroendocrine response to restraint in male and female rats

A parallel study of the modification in the opioid and immunological systems induced by acute restraint (RT) was carried out in male and female rats 24 hr after the treatment. beta-Endorphin-like immunoreactivity (beta-ELI) was measured in two brain areas (ventral hypothalamus [HYP] and periaqueductal gray matter [PAG]) and in the pituitary (anterior and neurointermediate lobes), together with plasma corticosterone (C) and ACTH. Immune function was measured as mitogen-induced Interferon-gamma (IFN-gamma) production by splenocytes. RT reduced beta-ELI levels in the PAG in males and females. Plasma levels of C and ACTH did not differ from the basal levels in restrained animals. RT reduced IFN-gamma production in both sexes, but this effect was more marked in females than in males. The possible relationship between the immune and opioid system is discussed.

Stressful life events and affective disorders inhibit pulsatile LH secretion in hypothalamic amenorrhea

The aim of this study was to evaluate relationships between emotional state and hypothalamic activity in patients with hypothalamic secondary amenorrhea. Sixty-seven normal weight patients with hypothalamic amenorrhea were submitted to concomitant psychological and LH pulsatility evaluation. Structured clinical interview for anxiety and depressive disorders (DSM III-R) as well as life events investigations (Paykel test) were performed. LH pulses (blood sampling every 10 min for 4 hr) were analyzed through DETECT program and Instantaneous Secretory Rate were computed. Twenty-one patients reporting life events associated to the onset of amenorrhea had LH pulse frequency (2.28 +/- 1.10 pulses/4 hr) lower than those without life events (3.40 +/- 1.46 p = .007). LH pulses amplitude was lower in patients meeting a DSM III-R (21 cases: 1.22 +/- 0.96 mIU/ml) diagnosis than in those without (1.99 +/- 1.20 p = .04) diagnosis. Plasma estradiol and FSH levels as well as duration of amenorrhea and Body Mass Index were similar among groups. It is concluded that psychogenic factors (namely the presence of life events related to the onset of menstrual disorder) are associated with significant and specific changes of hypothalamic activity which could be involved in determining hypogonadism.

Immunoreactive Met-enkephalin-like material in the testis of Rana esculenta: identification and localization

Methionine-enkephalin (Met-Enk) has been detected in the testis of the frog, Rana esculenta, using a reverse-phase high-performance liquid chromatography system coupled with a specific radioimmunoassay. By means of immunocytochemical techniques Met-Enk positive cells have been localized in interstitial and germinal compartments. Particularly, spermatogonia, spermatocytes, and spermatozoa were stained in seminiferous tubules, and numerous interstitial cells showed strong cytoplasmic immunoreactivity in summer animals. Variations in the concentration of Met-Enk immunoreactive material occurred during the annual cycle. Our data show that Met-Enk is present in testes of nonmammalian vertebrate species. These results suggest that autocrine and/or paracrine mechanisms may regulate testicular activity in amphibians.

Oral magnesium supplementation improves fetal circulation

It is well known that pregnancy is a condition in which plasma magnesium falls because of accumulation of the ion in the placenta and fetus. Magnesium (Mg) is therefore widely given as a supplement during pregnancy, particularly in cases of preterm labour. In our experience, the combination of oral Mg (magnesium pyrrolidone carboxylic acid) at a dose of 360 mg/day with conventional ritodrine treatment allows a reduction in ritodrine dosage, accompanied by a significant reduction in side effects. We therefore evaluated changes in fetal blood flow, using pulsed Doppler, in women submitted to combined magnesium and ritodrine treatment compared to those treated with ritodrine plus placebo. The Mg-treated group showed a decrease in vessel resistance both in the umbilical artery and in the fetal middle cerebral artery, indicating that fetal vasculature is sensitive to exogenous Mg. Measurement of plasma and mononuclear cell Mg showed an intracellular increase in the cation of about 10 per cent. We conclude that oral magnesium supplementation in pregnancy is safe and that it has a positive effect on the fetal circulation.

Evidence of alpha-N-acetyl beta-endorphin in human cerebrospinal fluid

Alpha-N-acetyl-beta-endorphin (Ac-beta-EP) is a post-translational product of beta-endorphin (beta-EP) with no analgesic properties. Ac beta-EP is present in human fetal and adult pituitary gland and cross-reacts in all available beta-EP assays. This study evaluates levels of Ac-beta-EP in the cerebrospinal fluid (CSF) of 22 normal subjects and 15 chronic headache sufferers. Since dopamine may play a role in the acetylation process, homovanillic acid levels were also determined. After extraction and high performance liquid chromatographic (HPLC) fractionation of CSF, an immunoreactive Ac-beta-EP peak was detected coeluting with reference peptide. Ac-beta-EP was detectable in all but 5 normal subjects. In headache sufferers, Ac-beta-EP levels were always detectable and their mean value was significantly higher than that of healthy subjects (11.6 +/- 11.8 vs 3.9 +/- 3.6 fmol/ml; P less than 0.01). Conversely, CSF beta-endorphin (beta-EP) concentrations were decreased in headache patients (9.8 +/- 9.4 vs 15.7 +/- 9.7 fmol/ml; P less than 0.05), and as a consequence the beta-EP/Ac-beta-EP ratio was also markedly reduced (P less than 0.005). No difference was observed for CSF homovanillic acid concentrations. These data demonstrate that HPLC coupled to radioimmunoassay allows the identification of low but significant amounts of Ac beta-EP in human CSF. This compound represents a confounding factor when beta-EP immunoreactivity is assessed by conventional methods. In headache sufferers, Ac-beta-EP levels were higher than normal, whereas beta-EP concentrations were lower.(ABSTRACT TRUNCATED AT 250 WORDS)

Antagonists of the NMDA receptor and allopurinol protect the olfactory cortex but not the striatum after intra-cerebral injection of kainic acid

Overstimulation of the NMDA receptor, as well as generation of excessive amounts of free radicals, has been implicated in excitotoxic brain injuries. We report here that two antagonists of the NMDA receptor and an inhibitor of the free radical-generating enzyme, xanthine oxidase, protect the olfactory cortex but not the striatum after intrastriatal injection of kainic acid. Our results suggest the existence of a precise link between excitotoxic activation of the NMDA receptor and neuropathology related to excessive amounts of free radicals. The focal point of this link may be the entry of Ca2+ through the NMDA receptor and the consequent activation of proteases and free radical-generating systems.

Induction of brain ornithine decarboxylase after systemic or intrastriatal administration of kainic acid

The activity of ornithine decarboxylase (ODC), the key enzyme of polyamine biosynthesis, dramatically increases after different types of brain injuries. The role of this induction is still unclear. We report here data on the temporal pattern of ODC induction caused by the excitotoxin kainic acid. After systemic administration, ODC activity increases severalfold peaking at 8 h in the prefrontal cortex and at 16 h in the olfactory cortex and hippocampus. After intrastriatal injection, the peak of induction is reached at 32 h, while a smaller and more transient increase is also observed in the contralateral, saline-injected striatum. We suggest that ODC induction is initially linked to overactivation of neural circuits and, later on, to the development of widespread neural damage.

Lactate infusion induces panic attacks in patients with premenstrual syndrome

A sodium lactate test was performed during the premenstrual phase in 35 women suffering from prospectively confirmed premenstrual syndrome (PMS) and in 16 controls in order to assess whether these patients were sensitive to this test and whether this sensitivity was accounted for primarily by the presence of concomitant panic disorder. Patients with PMS also underwent the Structured Clinical Interview for the DSM-III-R (SCID) to determine the presence of co-morbid anxiety and/or mood disorders. Only 31% of the PMS patients were free from a depressive/anxiety disorder, while nine patients met criteria for panic disorder, and the remaining 15 subjects were diagnosed as having anxiety and/or mood disorders. Lactate infusion induced panic attacks in 22 subjects (62.9%) and two controls (12.5%). Panickers were equally distributed among PMS patients with or without a concurrent anxiety/mood disorder. Although cardiovascular responses to lactate were similar among PMS patients regardless of the presence of concomitant anxiety/mood disorders, both plasma cortisol levels and panic and mood scores were higher during the test in those patients with concomitant panic disorder. These results suggest that PMS patients display an increased sensitivity to lactate, which is not primarily accounted for by the presence of co-morbid panic disorder.

Central changes of beta-endorphin-like immunoreactivity during rat tonic pain differ from those of purified beta-endorphin

Several studies have described changes in beta-endorphin-like immunoreactivity (beta-ELI) in the rat brain in response to pain and stress stimuli. In order to ascertain the components of beta-ELI, brain samples of rats experiencing acute prolonged (tonic) pain were evaluated for their beta-ELI and later submitted to a chromatographic purification allowing the measurement of beta-endorphin (beta-EP) and acetyl beta-EP. The chromatographic analysis of both ventromedial hypothalamus (VMH) and periaqueductal grey (PAG) homogenates indicates that beta-ELI is distributed in several fractions including shortened forms of beta-EP and their respective acetylated compounds. Quantitatively, while beta-ELI in formalin-injected animals was increased by 48% in VMH and 45% in PAG in respect to controls, the net increase of purified beta-EP was 1100% and 470%, respectively, for VMH and PAG. Moreover, the maximal increase of beta-ELI was evident at 120 min, in both tissues. In contrast, the beta-EP peak was reached at 30 min in VMH and at 60 min in PAG. Acetyl beta-EP was unchanged by treatment in both central areas. No correlation of beta-ELI and beta-EP was found in VMH. These data demonstrate that the evaluation of beta-ELI gives a poor estimate of beta-EP changes, due to several components of the endorphin family.

Occurrence of immunoreactive Met- and Leu-enkephalin-like peptides in the ovary of the green frog, Rana esculenta

In the present study, we have localized for the first time Met- and Leu-enkephalin-like material in the ovary of the anuran, Rana esculenta, using the indirect immunofluorescence method. The ovaries were sampled during the main representative phases of the annual reproductive cycle of the frog, living in a mountain pond (Colfiorito, Umbria at 820 m a.s.l.). Strong immunoreactivity to Met- and Leu-enkephalin antisera was observed in the follicle cells of the granulosa layer of vitellogenic oocytes; moreover, during this phase, immunofluorescent materials were also radially localized in the cytoplasm and in the perinuclear zone. The mature oocytes showed Met- and Leu-enkephalin-like immunostaining in the thecal layer and in several granules scattered in the peripheral zone of the yolk. The different pattern of Leu- and Met-enkephalin-like immunoreactivity in the frog ovary parallels and complements the changes occurring in the reproductive (May) and in the vitellogenetic (September) phases during the ovarian cycle. Consequently, these findings strongly support the hypothesis for a local synthesis of these peptides in the ovary and suggest their possible involvement in the control of ovarian function.

Ovarian opioids and the reproductive cycle of the frog Rana esculenta

In mammals, proopiomelanocortin-related peptides are involved in reproductive processes both at the hypothalamo-pituitary and ovarian levels. Using immunocytochemical, biochemical and physiological "in vitro" studies, we provide here evidence for a diffuse POMC-related opioid system in the frog Rana esculenta. Ovarian beta-endorphin (beta-EP) is expressed in thecal cells and changes during the reproductive cycle in an inverse relationship with follicular development. Seasonal changes in the ovary are different to those in the brain or in the pituitary. The ratio of acetylated vs native beta-EP in the ovary also changes over the reproductive period, affecting the biological activity of the peptide. During both the reproductive spring period and the summer post-reproductive phase pMol amounts of beta-EP stimulate follicular androgen secretion in vitro, in a naloxone-reversible way. In either period, an inhibition of estradiol, possibly mediated via other factors, is the result of opioid action. In conclusion, these data demonstrate for the first time the widespread presence of beta-EP-related peptides in the frog Rana esculenta. Both immunocytochemical and biochemical evidence, as well as in vitro responses, support a physiological role for beta-EP in ovarian seasonality during the reproductive cycle of this amphibian.

Psychosomatic disorders related to gynecology

In this paper current issues on four psychosomatic disorders related to gynecology will be reviewed. The history, nosological problems and psychoneuroendocrine correlates of psychogenic amenorrhea have been summarized taking into account the important role of psychological factors in inducing loss of menses. Definition and diagnostic problems in assessing menstrually related disorders (formerly premenstrual syndrome) have been reviewed, looking at this syndrome as a disorder of adaptation to the cyclical changes of neuroendocrine functions. The impact of stress on fertility and, on the other hand, the effects of infertility on psychological well-being have been pointed out trying to ascertain the pathways involved in these mutual relationships. Finally, the issue of mood changes at menopause and the effects of steroid replacement on affective state have been discussed. As a whole, these evidences indicate the importance of a close cooperation between gynecologist and psychiatrist in the management of gynecological disorders.

Peripheral opioid secretory pattern in anorexia nervosa

The peripheral secretion of endogenous opioids was studied in 10 women with restrictive anorexia nervosa and 10 age- and sex-matched healthy controls. The circadian rhythm of beta-endorphin (beta-EP) and beta-lipotropin (beta-LPH), and their responses to the administration of corticotropin releasing hormone (CRH, 1 micrograms/kg body weight, i.v.), clonidine (150 microgram, i.v.), domperidone (10 mg, i.v.), and 5-hydroxytryptophan (5-HTP, 200 mg, p.o.) were examined in patients and controls. The results revealed increased nocturnal secretion of beta-EP and diurnal-nocturnal secretion of beta-LPH with loss of circadian rhythmicity of both peptides, normal response to CRH stimulation, blunted response to clonidine and domperidine, and normal beta-EP and blunted beta-LPH response to 5-HTP stimulation. The data suggest a complex alteration of peripheral opioids and of central aminergic mechanisms that regulate proopiomelanocortin-derived peptide secretion and eating behavior.

Oral magnesium successfully relieves premenstrual mood changes

Reduced magnesium (Mg) levels have been reported in women affected by premenstrual syndrome (PMS). To evaluate the effects of an oral Mg preparation on premenstrual symptoms, we studied, by a double-blind, randomized design, 32 women (24-39 years old) with PMS confirmed by the Moos Menstrual Distress Questionnaire. After 2 months of baseline recording, the subjects were randomly assigned to placebo or Mg for two cycles. In the next two cycles, both groups received Mg. Magnesium pyrrolidone carboxylic acid (360 mg Mg) or placebo was administered three times a day, from the 15th day of the menstrual cycle to the onset of menstrual flow. Blood samples for Mg measurement were drawn premenstrually, during the baseline period, and in the second and fourth months of treatment. The Menstrual Distress Questionnaire score of the cluster "pain" was significantly reduced during the second month in both groups, whereas Mg treatment significantly affected both the total Menstrual Distress Questionnaire score and the cluster "negative affect." In the second month, the women assigned to treatment showed a significant increase in Mg in lymphocytes and polymorphonuclear cells, whereas no changes were observed in plasma and erythrocytes. These data indicate that Mg supplementation could represent an effective treatment of premenstrual symptoms related to mood changes.

Magnesium prophylaxis of menstrual migraine: effects on intracellular magnesium

The effects of oral Magnesium (Mg) pyrrolidone carboxylic acid were evaluated in 20 patients affected by menstrual migraine, in a double-blind, placebo controlled study. After a two cycles run-in period, the treatment (360 mg/day of Mg or placebo) started on the 15th day of the cycle and continued till the next menses, for two months. Oral Mg was then supplemented in an open design for the next two months. At the 2nd month, the Pain Total Index was decreased by both Placebo and Mg, with patients receiving active drug showing the lowest values (P less than 0.03). The number of days with headache was reduced only in the patients on active drug. Mg treatment also improved premenstrual complaints, as demonstrated by the significant reduction of Menstrual Distress Questionnaire (MDQ) scores. The reduction of PTI and MDQ scores was observed also at the 4th month of treatment, when Mg was supplemented in all the patients. Intracellular Mg++ levels in patients with menstrual migraine were reduced compared to controls. During oral Mg treatment, the Mg++ content of Lymphocytes (LC) and Polymorphonucleated cells (PMN) significantly increased, while no changes in plasma or Red Blood Cells were found. An inverse correlation between PTI and Mg++ content in PMN was demonstrated. These data point to magnesium supplementation as a further means for menstrual migraine prophylaxis, and support the possibility that a lower migraine threshold could be related to magnesium deficiency.

Pituitary and brain beta-endorphin in male and female rats: effects of shock and cues associated with shock

The present experiment was designed to study whether or not prior exposure to inescapable shock is accompanied by sex-dependent changes in pituitary and central levels of immunoreactive beta-endorphin, which is proposed to play an important role in opioid analgesia induced by aversive stimulation. Further, the effects of brief reexposure (5 min) to the chamber where inescapable shock was experienced earlier, were established in both sexes. Elevated levels of beta-endorphin were found 24 hours after inescapable shock, in the anterior pituitary of males and in the midbrain periaqueductal gray of both males and females. Reexposure to the experimental chamber only affected beta-endorphin levels if shock had been experienced in this chamber. Reexposure after inescapable shock reduced beta-endorphin content of the arcuate nucleus of males and beta-endorphin content of the periaqueductal gray of males and females. The present results are related to previous findings of sensitization and conditioning of analgesic reactions. The sex differences found in the present experiment are discussed with respect to sex-dependent behavioral consequences of inescapable shock.

Central beta-endorphin system involvement in the reaction to acute tonic pain

The involvement of the beta-endorphin (B-EP) system during acute prolonged (tonic) pain was investigated by biochemical and behavioral approaches in freely-moving rats after subcutaneous injection of a small amount of a dilute formaldehyde solution (0.08 ml, 5%) in a forepaw. Beta-endorphin-like immunoreactivity levels were increased over the respective control groups in rats killed 30, 60 and 120 min after injection in discrete regions of the rat brain, namely ventro-medial hypothalamus, ventro-basal thalamus and periaqueductal gray matter, and at 30 and 60 min in postero-medial thalamus. In a separate group of experiments a small amount of anti-B-EP or normal rabbit serum was injected in the lateral ventricle; 6 h later rats received formalin injection as in previous groups and their behavior was scored over the following 2 h. A significant hyperalgesia (as expressed by an increase in the amount of time rats spent licking or chewing the injected paw) was observed 10-50 min and 70-80 min after formalin in the anti-B-EP icv-injected group. Other behavioral parameters such as general motor activity, grooming and limb flexion were not different in the two groups, nor was animal behavior prior to formalin injection. Altogether these data suggest that the central beta-endorphin system is triggered by prolonged noxious stimulation in freely-moving animals, and in turn plays a physiological role in the modulation of the reaction to, or perception of, tonic pain.

Unresponsiveness of the endorphinergic system to its physiological feedback in obesity

Beta-endorphin (beta-Ep) plasma levels are higher in obese patients than in normal subjects. To establish that this finding constitutes hyperendorphinemia, 28 obese patients aged 12-55 years, six males and 22 females, (weighing 61-117 kg) were investigated twice by an overnight 1-mg p.o. dose dexamethasone suppression test (DST) before and after weight loss. beta-Ep was measured by radioimmunoassay (RIA). Before body weight loss, beta-Ep was higher than normal and unresponsive to DST, whereas ACTH and cortisol were suppressible. After weight loss, beta-Ep was slightly reduced but still insensitive to DST. ACTH and cortisol were responsive as usual. Findings suggest a resistance to DST in obesity as far as beta-Ep is concerned. The disorder persists even after weight loss, indicating that hyperendorphinemia is not secondary to body weight excess. Accordingly, one can argue that the unresponsiveness of the endorphinergic system to its physiological feedback is a pathophysiological characteristic of obesity.

Effect of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in goldfish brain

The neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which selectively damages dopaminergic neurons in mammals, caused a marked depletion of tyrosine hydroxylase (TH) immunoreactivity in the goldfish brain. The concomitant ultrastructural observations showed the neurotoxic effect of MPTP on telencephalic, diencephalic and medullar neurons. The affected neurons revealed darkening of the cytoplasm and swelling of the mitochondria and the endoplasmic reticulum. Concomitant significant decreases in dopamine (DA) and noradrenaline (NA) levels were determined in the brain areas where morphological observations were performed. The loss of catecholamine levels was completely prevented by the treatment with the monoamine oxidase (MAO) inhibitor pargyline to prevent MPTP oxidation. The results indicate that in goldfish brain, acute MPTP administration causes selective catecholamine depletion, without altering the serotoninergic system.

Naproxen sodium in menstrual migraine prophylaxis: a double-blind placebo controlled study

In this study, the efficacy of Naproxen sodium (Nxs) in the prophylaxis of Menstrual Migraine (MM) was tested, versus Placebo (PL). Forty women suffering from MM were admitted to a double-blind treatment protocol with Nxs 550 mg twice each day by mouth or Placebo (PL), for 3 months; in the next 3 months all the women were treated with the active drug in an open study. The headache intensity and duration, as well as the number of days of headache and the analgesic consumption, were significantly reduced with Nxs compared to PL. The efficacy of Nxs, shown also in improving premenstrual pain, and its good tolerability, support the use of this drug in the prophylactic therapy of MM.

A new 5-HT2 antagonist (ritanserin) in the treatment of chronic headache with depression. A double-blind study vs amitriptyline

The exact relationship between depression and chronic headache remains unclear. Considerable clinical and pharmacological evidence suggests the existence of a common biological terrain. Many antidepressant drugs are effective in the treatment of migraine and chronic headache disorders. Ritanserin, a new very selective serotonin-2 (5-HT2) antagonist, has recently shown both analgesic and antidepressant properties. The present study compares in a double-blind design, the effectiveness of ritanserin and amitriptyline, a well-known antidepressant extensively used in migraine prophylaxis. Thirty-eight patients (30 females and 8 males ranging in age from 20 to 50 yrs) were classified according to the International Headache Society criteria as: patients with chronic tension-type headache (CTH) (11 cases) and patients with coexisting migraine and CTH (MCTH) (27 cases). Only patients with a score equal to or higher than 18 on the Hamilton Rating Scale for Depression (HRSD) were included. Ritanserin was highly effective in reducing Pain Total Index and analgesic consumption in chronic headache, and its activity was similar to that observed during amitriptyline treatment. A significant improvement of HRSD and HRSA (Hamilton Rating Scale for Anxiety) scores was observed during both treatments. The main results of our study concern the demonstration of antiheadache and antidepressive properties of ritanserin. To better define the profile of the patients and their clinical responsiveness to the treatment, dexamethasone suppression test, clonidine test and nociceptive flexion reflex were investigated in our patients. Our data confirm the usefulness of these methods as markers of chronic headache with depression.

[Plasma levels of beta-endorphin , ACTH and cortisol in obese patients subjected to several weight-loss treatments]

It is now well-known that the plasmatic levels of beta-endorphin (B-Ep) in subjects suffering from hyperphagie obesity during childhood, adolescence and adult age, are higher than those of normal weight standard-wright. The causes are still unknown. In obese subjects, there is also a dissociation between plasmatic levels of B-Ep and of ACTH, in spite of the common origin of Proopiomelanocortin (POMC). On the basis of these observations we studied the plasmatic levels of B-Ep, ACTH and cortisol, basal and after DXM, before and after the reduction of body weight. With the aim of evaluating pharmacological interference, the obese subjects were treated with diet alone or diet associated with an anorectic and serotoninergic drug (fenfluramin). The results have shown that after slimming, obtained with diet alone or with the help of the serotoninergic drug, the hyperendorphinemia persists both in basal conditions and after the DXM test. The verification of such behaviour in some psychiatric diseases supports our assumption of a link between hyperendorphinemia, behaviour alterations, hyperphagy and obesity.

Opioid control of the hypothalamus-pituitary-adrenal axis cyclically fails in menstrual migraine

To assess the biological correlates of the precipitation of migraine attacks in the perimenstrual period, plasma beta-endorphin (beta-EP) and cortisol responses to naloxone (8 mg iv) and corticotropin releasing hormone (100 micrograms iv) were evaluated in both the follicular phase and the premenstrual period in 7 patients suffering from menstrual migraine and in 7 healthy, asymptomatic control volunteers. In the controls, naloxone evoked a significant release of both beta-EP (F = 5.86, p less than 0.002) and cortisol (F = 4.43, p less than 0.008), independently of the menstrual cycle phase (F = 0.31 and 1.04, for beta-EP and cortisol, respectively). Menstrual migraine patients, on the other hand, showed a significant hormone response only in the follicular phase, not in the premenstrual period. Corticotropin releasing hormone significantly increased beta-EP and cortisol in both the controls and the menstrual migraine patients, independently of the menstrual cycle phase. In both the naloxone and corticotropin releasing hormone testings, the basal beta-EP levels measured in the premenstrual period were lower than those observed in the follicular phase (p less than 0.02). These data demonstrate a cyclical, premenstrual dysfunction of the hypothalamic control exerted by opioids on the hypothalamus-pituitary-adrenal axis. Impairment of this fundamental adaptive mechanism (involved in stress responses and in pain control) could establish a causal relationship between menstrual-related migraine attacks and premenstrual opioid hyposensitivity.

[Neuroendocrine changes and affective disorders in patients with hyperphagic obesity]

Circulating levels of cortisol and beta-endorphin were evaluated in basal condition and following dexamethasone administration in 20 healthy subjects and in 60 subjects suffering from hyperphagic obesity. Moreover, mental tests were administered to these subjects in order to evaluate the affective state. Our data showed that in obese patients B-Ep plasma levels were significantly higher than those of the control group, while cortisol plasma levels were similar in the two groups. Dexamethasone administration decreased cortisol plasma levels in normal and obese subjects, while did not modify B-Ep plasma levels in obese subjects. However, after dexamethasone administration 16.6% of the obese subjects did not show a complete decrease of cortisol level. This group of subjects obtained the highest scores for depression and hypochondria to MMPI.

Time-course of opioid and pituitary-adrenal hormone modifications during the immobility reaction in rabbits

A series of experiments in male rabbits examined the influence of tonic immobility (animal hypnosis) on the opioid and pituitary-adrenal hormones. The aims of the experiments were to follow the temporal modifications in hormone parameters and to discriminate the effects of immobility from those of the manipulative procedure to induce the reaction. Results show that immobility elicits increases in plasma ACTH and beta-EP, but no modifications in pituitary beta-EP. The effects of induction procedure were dissociable from those of immobility, the most marked effect being a prolonged, sustained increase of corticosterone plasma levels. Results support the hypothesis of the opioid involvement in the physiological control of immobility reaction and indicate different mechanisms underlying the immobility response and the procedure of induction.

Beta-endorphin, insulin, ACTH and cortisol plasma levels during oral glucose tolerance test in obesity after weight loss

In order to clarify a possible relationship between opioid peptides and glucose homeostasis in obesity we studied Beta-Endorphin (B-Ep), ACTH, cortisol and insulin plasma levels in response to an oral glucose tolerance test (OGTT) in 8 subjects after a hypocaloric diet for 90 days. We obtained through this treatment a weight loss superior to 30% of the initial weight excess (WE) compared with ideal body weight. Moreover, we compared the obtained results with our preliminary study that was performed with the same protocol but without caloric restriction. B-Ep was measured by RIA after silicic acid extraction and G75 Sephadex column chromatography. ACTH, insulin and cortisol were measured directly on plasma by an RIA method. Basal and during OGTT-induced levels of glucose, insulin, ACTH and cortisol decreased in comparison with the values obtained before diet. Conversely, B-Ep remained higher than normal both in the basal condition and during OGTT, and showed values consistently similar to those before diet. These data show that hyperinsulinemia is corrected by weight loss, while hyperbetaendorphinemia remains unchanged. Accordingly, it can be suggested that no direct relationship occurs between hyper-B-Ep-hyper-IRI in obesity. A further insight into the role of hyper-B-Ep in obesity is, thus, necessary, assuming as hypothesis that the increase in B-Ep may be a cause and not a corollary of the polymorphic aspects of obesity.