Different patterns of central and peripheral beta EP, beta LPH and ACTH throughout life

Age Differences in the Time Course and Magnitude of Changes in Circulating Neuropeptides After Pain Evocation in Humans

This study tested the hypothesis that older adults would have a stronger response for substance P (facilitatory) but weaker response to β-endorphin (inhibitory), in magnitude as well as time course. Eight younger and 9 older adults underwent 3 experimental sessions using well validated laboratory pain models: cold pressor task, contact heat pain, and a nonpainful control. Blood was collected through an indwelling catheter at baseline and 3, 15, 30, 45, and 60 minutes after stimuli administration. Older adults had higher baseline levels of both neuropeptides suggesting increased peripheral activity compared with younger adults. After the cold pressor task, older adults demonstrated a quick and strong release of substance P with dramatic recovery, whereas young adults maintained a constant low-grade response. Unlike substance P, β-endorphin increased between 3 and 15 minutes for both groups with the upsurge substantially higher for older adults. After heat pain, younger adults had an immediate surge in circulating substance P and β-endorphin that was more pronounced than among older adults. However, levels of substance P for younger adults slowly tapered whereas they continued to climb for the older adults through 30 minutes. β-endorphin peaked at 30 minutes for both groups and returned to baseline. No changes were observed during the nonpainful control session.

PERSPECTIVE

Older adults had higher baseline levels of substance P and β-endorphin suggesting increased peripheral activity compared with younger adults. After pain evocation, older adults demonstrated a more intense early response for both neuropeptides suggesting peripheral mechanisms involved in the response to pain may change with age.

Do low levels of beta-endorphin in the cerebrospinal fluid indicate defective top-down inhibition in patients with chronic neuropathic pain? A cross-sectional, comparative study

OBJECTIVE

Pain medicine still lacks mechanism-specific biomarkers to guide diagnosis and treatment, and defective top-down modulation is an important factor in the pathophysiology of chronic pain conditions. Using modern analytical tools and advanced multivariate statistical analysis, the aim of this study was to revisit two classical potential biomarkers of pro- and anti-nociception in humans (substance P and beta-endorphin), focusing particularly on the cerebrospinal fluid (CSF).

DESIGN

Cross-sectional, comparative, observational study.

SUBJECTS

Patients with chronic, post-traumatic and/or post-surgical, neuropathic pain refractory to conventional treatment (N = 15) and healthy controls (N = 19) were included.

METHODS

Samples were taken from CSF and blood, and levels of substance P and beta-endorphin were investigated using a Luminex technology kit.

RESULTS

We found low levels of beta-endorphin in the CSF of neuropathic pain patients (66 ± 11 pcg/mL) compared with healthy controls (115 ± 14 pcg/mL) (P = 0.017). Substance P levels in the CSF did not differ (20 ± 2 pcg/mL, 26 ± 2, P = 0.08). However, our multivariate data analysis showed that belonging to the patient group was associated with low levels of both substances in the CSF. A higher correlation between the levels of beta-endorphin and substance P in CSF was found in healthy controls than in patients (rs  = 0.725, P < 0.001 vs. rs  = 0.574, P = 0.032).

CONCLUSIONS

Patients with chronic neuropathic pain due to trauma or surgery had low levels of beta-endorphin in the CSF. We speculate that this could indicate a defective top-down modulation of pain in chronic neuropathic pain. Our results also illustrate the importance of taking a system-wide, multivariate approach when searching for biomarkers.

Volume transmission of beta-endorphin via the cerebrospinal fluid; a review

There is increasing evidence that non-synaptic communication by volume transmission in the flowing CSF plays an important role in neural mechanisms, especially for extending the duration of behavioral effects. In the present review, we explore the mechanisms involved in the behavioral and physiological effects of β-endorphin (β-END), especially those involving the cerebrospinal fluid (CSF), as a message transport system to reach distant brain areas. The major source of β-END are the pro-opio-melano-cortin (POMC) neurons, located in the arcuate hypothalamic nucleus (ARH), bordering the 3^rd ventricle. In addition, numerous varicose β-END-immunoreactive fibers are situated close to the ventricular surfaces. In the present paper we surveyed the evidence that volume transmission via the CSF can be considered as an option for messages to reach remote brain areas. Some of the points discussed in the present review are: release mechanisms of β-END, independence of peripheral versus central levels, central β-END migration over considerable distances, behavioral effects of β-END depend on location of ventricular administration, and abundance of mu and delta opioid receptors in the periventricular regions of the brain.

Neurobehavioral impact of menopause on mood

The menopausal transition is a time of risk for mood change ranging from distress to minor depression to major depressive disorder in a vulnerable subpopulation of women in the menopausal transition. Somatic symptoms have been implicated as a risk factor for mood problems, although these mood problems have also been shown to occur independently of somatic symptoms. Mood problems have been found to increase in those with a history of mood continuum disorders, but can also occur de novo as a consequence of the transition. Stress has been implicated in the etiology and the exacerbation of these mood problems. Estrogen and add-back testosterone have both been shown to positively affect mood and well-being. In most cases, the period of vulnerability to mood problems subsides when the woman's hormonal levels stabilize and she enters full menopause.

Preoperative concentration of beta-lipotropin immunoreactive material in cerebrospinal fluid: a predictor of postoperative pain?

Levels of beta-endorphin immunoreactive material (IRM) in cerebrospinal fluid (CSF) have been reported to correlate inversely with postoperative morphine requirement. Considering proopiomelanocortin (POMC) derivatives as predictors for sensitivity to postoperative pain, we determined authentic beta-endorphin (beta-endorphin(1-31)), beta-lipotropin IRM, N-acetyl-beta-endorphin IRM and ACTH in CSF of 17 patients undergoing hip or knee arthroplasty, before surgery (t(A)), immediately after termination of propofol infusion and still under spinal anesthesia (t(B)), under postoperative pain (t(C)) and one day after surgery (t(D)); patients rated their severity of pain on a visual analogue scale (VAS) at those four times. In all patients CSF concentrations of N-acetyl-beta-endorphin IRM and beta-lipotropin IRM were found to be increased after terminating the propofol infusion with spinal anesthesia still effective at t(B). Patients did not feel pain at times t(A), t(B) or t(D); however, they reported moderate to considerable pain at t(C). There were no correlations of postoperative pain severity at t(C) with ACTH, beta-endorphin(1-31) or N-acetyl-beta-endorphin IRM concentrations in CSF. In contrast, we observed significant inverse correlations (Spearman's rank correlation coefficients between -0.83 and -0.85, p<0.01) for postoperative pain severity with beta-lipotropin IRM concentrations in CSF at t(C), and, in addition, at t(A), t(B) and t(D); thus, postoperative pain severity appeared to be dependent on a central system controlling sensitivity to pain, linked to a POMC system releasing beta-lipotropin IRM into CSF and already active at times t(A) and t(B). We conclude that beta-lipotropin IRM in CSF might be considered to serve as a predictor of sensitivity to postoperative pain.

The effects of tibolone on mood and libido

OBJECTIVE

To review published data pertaining to the effects of tibolone on sexual parameters, mood, and cognitive function in postmenopausal women.

DESIGN

A review of all relevant published, peer-reviewed studies.

RESULTS

Tibolone is a compound that can be selectively metabolized by individual tissues to its estrogenic, progestogenic, or androgenic metabolites and hence exhibits tissue-specific hormonal effects. Tibolone also lowers sex hormone binding globulin, thus increasing free estradiol and testosterone levels. Tibolone alleviates climacteric vasomotor symptoms and displays a dominant progestogenic effect on the endometrium. Tibolone normalizes the vaginal karyopyknotic and maturation indexes and alleviates symptomatic atrophic vaginitis. Women treated with tibolone report significant reductions in vaginal dryness and dyspareunia, effects that may be secondary to both estrogenic and androgenic actions. Randomized studies indicate tibolone has positive effects on mood compared with placebo and alleviates several adverse mood parameters to a similar extent as conventional hormone replacement therapy. Improved mood is associated with increased plasma beta-endorphin. With respect to cognition, tibolone seems to improve semantic memory but does not significantly improve recognition memory. Tibolone is associated with improvements in sexual function that seem to be greater than those achieved with standard hormone replacement therapy.

CONCLUSION

Published studies indicate beneficial effects of tibolone on both libido and mood, which otherwise significantly compromise physical, psychological, and social well-being. Hence, tibolone provides another option for menopausal women experiencing loss of libido as part of their symptomatology or who have persistent low libido despite adequate estrogen/progestin replacement therapy.

Role of the central endogenous opiate system in patients with syndrome X

BACKGROUND

To evaluate the role of the endogenous opioid system (EOS) in abnormal pain perception in patients with syndrome X, we used a neuroendocrine approach, evaluating plasmatic luteinizing hormone (LH) changes after naloxone, a competitive antagonist of opioid receptors able to unblock tonic EOS inhibition on gonadotropin release. Thus LH response to naloxone test indicates the central EOS activity on hypothalamic luteinizing hormone-releasing hormone (LH-RH) inhibitory opioid receptors.

METHODS

Ten patients with syndrome X, 10 age-matched male patients with coronary artery disease (CAD), and 10 normal subjects were analyzed. Naloxone tests were performed between 8 and 9 am. Basal beta-endorphin and LH levels were determined on 4 blood samples at 20-minute intervals; after naloxone (0.1 mg/kg intravenously in 4 minutes), LH was measured on 8 samples at 15-minute intervals. In all patients the test was also performed after LH-RH administration. Anginal pain on exercise testing was subjectively scored on a 1 to 10 analogic scale and wall motion abnormalities were quantified by a wall motion score index.

RESULTS

Significant differences were found in LH release after naloxone (CAD 260.3 +/- 42.6 vs syndrome X 151.6 +/- 48.5 mIU/mL, P <.05), angina score (CAD 5.5 +/- 1.3 vs syndrome X 7.2 +/- 1.7, P <.05), and wall motion abnormalities (CAD 3.6 +/- 1. 2 vs syndrome X 2.8 +/- 1.9, P <.05).

CONCLUSIONS

The reduced LH release after naloxone in syndrome X, with a normal LH-RH response, suggests a lower central EOS activity, which may be related to the higher anginal pain perception.

β-endorphin binding in cultured adrenal cortical cells

The polypeptide β-endorphin binds to cultured bovine adrenal cortical cells in a naloxone insensitive manner, β-endorphin and N-Acetyl-β-endorphin are equipotent in inhibiting binding. The amino terminal 27 amino acid fragment referred to as β-endorphin[1-27] shows no ability to inhibit binding, whereas the carboxy-terminal tetrapeptide Lys-Lys-Gly-Glu partially inhibits binding. ACTH, angiotensin II and met-enkephalin show little or no ability to inhibit β-endorphin binding. Competition bin-ding reveals an apparently single affinity class with Kd of 33 nM. Molecular cross linking experiments reveal putative receptor subunits of 85 kD, 64 kD, 54 kD and 44 kD. The lower molecular weight bands are preferentially cross-linked by a hydrophobic cross linking reagent, in contrast to the two higher molecular weight bands, which are cross linked equally by hydrophobic and water soluble cross linking reagents. The β-endorphin binding characteristics of adrenal cortical cells revealed here are quite similar to those of a class of non-opioid β-endorphin receptors previously shown to exist in cells of the immune system.

Twenty-four-hour beta-endorphin secretory pattern in stroke patients

BACKGROUND AND PURPOSE

Abnormalities of hypothalamo-pituitary-adrenocortical axis function have been observed frequently in stroke patients. The aim of this study was to investigate plasma beta-endorphin and cortisol 24-hour secretory patterns in patients early after stroke and in the convalescent period to evaluate a possible influence of brain damage on hormonal circadian pattern.

METHODS

Patients (n = 15; age, 46 to 75 years) were evaluated in the first 24 hours and 10 days after hospital admission for ischemic cerebral stroke and compared with 15 age- and sex-matched normal subjects. Blood samples for beta-endorphin and cortisol determination were drawn every 4 hours from 8 AM to 8 PM and every 2 hours from midnight to 6 AM.

RESULTS

Mean 24-hour beta-endorphin and cortisol levels, recorded in the acute phase, were significantly (P < .05) higher than those recorded in normal subjects; circadian rhythm was not demonstrable for either hormone. In the convalescent period, plasma cortisol 24-hour mean values and circadian rhythm returned to the normal range, whereas the plasma beta-endorphin 24-hour mean values and circadian rhythm did not.

CONCLUSIONS

Cerebral stroke induces abnormalities of beta-endorphin and cortisol circadian secretion. Whereas cortisol abnormalities are transient, those of beta-endorphin last longer. The dissociation between beta-endorphin and cortisol 24-hour secretory patterns might potentially serve as a marker of psychoneurological abnormalities occurring after stroke.

Hypogonadism induced by African trypanosomes in humans and animals

1. The clinical syndromes of the African trypanosomiasis (also called sleeping sickness in humans) are defined. The basic knowledge on the hypothalamo-anterior pituitary-gonad axis functions is briefly recalled. 2. Hypogonadism caused by the trypanosomes both in men and in women as well as in male and female animals are extensively reviewed in publications over the last two decades as well as on our own very recent works which provided new insights on the physiopathology of the gonadal disorders.

Plasma and cerebrospinal fluid beta-endorphin in chronic tension-type headache

Previous studies have provided evidence of an increased sensitivity to pain, a decreased hypothalamic opioid tone, and decreased cerebrospinal fluid (CSF) beta-endorphin (beta-EP) concentration in patients with primary chronic headache. We applied separate specific radioimmunoassays for beta-EP in CSF and plasma on samples from age-matched controls and a group of 50 patients with chronic tension-type headache (CTH) fulfilling the diagnostic criteria set by the International Headache Society. Median CSF beta-EP concentrations (95% confidence limits) were 12.8 pmol/l (11.0-14.5) in CTH patients and 11.9 pmol/l (10.9-14.2) in the control group, which is not significantly different (P = 0.28). Plasma beta-EP concentrations did not differ either, being 3.1 pmol/l (2.4-3.7) and 3.3 pmol/l (1.8-4.0) in the patients with CTH and in controls, respectively (P = 0.88). Plasma and CSF beta-EP concentrations did not correlate. Reversed-phase high performance liquid chromatography (HPLC) of CSF pools from the headache patients and controls revealed similar profiles of beta-EP-immunoreactivity both when C-terminally and N-terminally directed antisera were used, suggesting a normal post-translational processing of the pro-opiomelanocortin gene in patients with CTH. beta-EP is not involved in the pathogenesis of CTH, or such a role is not reflected in CSF or plasma concentrations of the neuropeptide.

Endogenous opioid system modulation in anginal pain: demonstration of its central activity

Plasma beta-endorphin levels provide controversial results on the role of endogenous opioid system in modulation of anginal pain. As an alternative, the action of plasmatic luteinizing hormone after administration of naloxone was investigated: naloxone blocks the tonic endogenous opioid system inhibition of gonadotropin release; thus, the level of luteinizing hormone after naloxone administration is an index of central endogenous opioid system activity. Twenty patients with coronary artery disease and positive results of stress tests were selected: 10 had angina (group I) and 10 did not (group II). Ten healthy subjects were also studied as a control group (group III). In all patients basal plasma beta-endorphin levels, basal luteinizing hormone plasma levels (every 15 minutes for 1 hour) and luteinizing hormone plasma levels after administration of 0.1 mg/kg naloxone over 4 minutes (every 15 minutes for 2 hours) were determined. In 15 patients the test was performed after luteinizing hormone releasing hormone was given. The integral concentration time of luteinizing hormone plasma level during baseline (LHiB) and after administration of naloxone (LHiN) or luteinizing hormone releasing hormone (LHiRH), the ratio (LHiN:LHiB and LHiRH:LHiB) and the differences (LHiN-LHiB and LHiRH-LHiB) between the postinfusion period and baseline were calculated. No difference was found in beta-endorphin plasma levels and luteinizing hormone response after luteinizing hormone releasing hormone infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebrospinal fluid beta-endorphin in Rett syndrome

An hypothesis of increased endorphinergic activity has been proposed to account for the characteristic symptoms of Rett syndrome. Cerebrospinal fluid samples from eight girls with Rett syndrome were analysed for beta-endorphin (beta-EP) immunoactivity and compared with samples from a control group of 15 children with acute leukaemia in remission. Severity of symptoms was not found to be related to beta-EP level. A group of early-treated adolescents with phenylketonuria had beta-EP levels similar to the Rett syndrome patients, but no symptoms resembling theirs. Therefore it is unlikely that increased levels of beta-EP are of primary pathogenetic significance. The conflicting findings of many earlier reports may be a result of differences between control groups.

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.

Resistance of beta-endorphin to dexamethasone inhibition in Parkinson's and Alzheimer's diseases

The response of plasma beta-endorphin (beta-EP) to dexamethasone suppression was studied in 14 patients with Alzheimer's disease (AD), 14 patients with Parkinson's disease (PD), and 13 age-matched controls in order to evaluate whether an impairment of the opiate system is present in these neurodegenerative disorders. Basal circulating beta-EP was in normal range in all subjects, although the mean concentration was slightly reduced in the patients compared to controls. After 1 mg dexamethasone given at 11:00 p.m. the night before, plasma beta-EP concentration measured at 08:00 a.m. and 04:00 p.m. was not inhibited in AD and PD patients while it was significantly reduced in controls. Circulating ACTH and cortisol were similar in patients and controls and a normal inhibition of plasma cortisol after dexamethasone was observed in 13/14 AD and 12/14 PD patients. The resistance of beta-EP to dexamethasone inhibition is consistent with previous clinical and experimental data indicating a disorder of the opiate system in brain degenerative diseases.

Relationship between cerebrospinal fluid beta-endorphin and plasma pituitary-gonadal hormone levels in women

Brain beta-endorphin (beta-EP) plays an important role in regulating the hypothalamus-pituitary-gonadal axis activity. Cerebrospinal fluid (CSF) beta-EP levels seem to reflect the central rather than pituitary secretion. With the aim to correlate the changes of plasma estradiol (E2), progesterone, luteinizing hormone (LH) and follicle-stimulating hormone with brain beta-EP, CSF levels of beta-EP were measured in 15 normally cycling and 15 postmenopausal women. CSF beta-EP levels in post-menopausal women were lower than in fertile women. A positive correlation between plasma E2 and CSF beta-EP level was found in all women. In fertile women CSF beta-EP levels were inversely correlated to plasma gonadotropin levels. These results showed that CSF beta-EP levels differ between fertile and postmenopausal women and are correlated with plasma LH and E2, suggesting a strong linkage between central beta-EP levels and pituitary-gonadal axis hormones.

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.

Effects of opioid blockade with nalmefene in older impotent men

We evaluated the effect of the opioid antagonist nalmefene on the HPG axis and on food consumption in 14 older impotent men. These patients had low to low normal mean serum testosterone values and normal gonadotrophin levels on screening evaluation. Normal response to GnRH was demonstrated in all the men. The protocol called for 24 hours of evaluation before and during administration of nalmefene 2.0 mg IV every 8 hours for 3 doses. During each 24 hour period, the following determinations were made: serum testosterone, FSH, and LH by five separate determinations between 8 AM and noon; 8 AM and 11 PM serum cortisols; 24 hour urine collections for free cortisol; and nocturnal penile tumescence (NPT). Food consumption was measured from 4 PM to 10 AM during the two periods. Nalmefene resulted in significant rises in testosterone, LH, and FSH. Nalmefene significantly elevated morning and evening cortisol measurements in all the patients. Nalmefene decreased total calorie consumption, principally by decreasing fat consumption. There was no effect on NPT. We conclude that in older impotent men, nalmefene acutely increases activity of the HPG axis and decreases calorie intake predominantly by decreasing fat consumption.

CSF beta-endorphin, HVA and 5-HIAA of dementia of the Alzheimer type and Binswanger's disease in the elderly

Cerebrospinal fluid (CSF) concentration of beta-endorphin (beta-Ep), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) was measured in 15 patients with dementia of the Alzheimer type (DAT) and in 16 patients suspected of having Binswanger's disease (BD) by MRI, which sometimes resembles DAT clinically. These were classified into three stages according to severity of dementia, Stage 1 (mild dementia)-Stage 3 (severe dementia). CSF levels of HVA decreased significantly in severe dementia, but the level of 5-HIAA did not correlate with dementia severity in both dementia groups. beta-Ep levels did not differ significantly between any stages of DAT, and among controls. beta-Ep levels, however, in BD Stage 1 (27.5 +/- 5.9 pg/ml) were significantly higher (p less than 0.05), but level in Stage 3 (6.7 +/- 2.0) was significantly lower (p less than 0.001) than in the controls (19.2 +/- 4.5). These results suggest that CSF beta-Ep may depend on the cause of dementia rather than severity of dementia, and could possibly distinguish the closely resembling BD from true DAT.

Reduced cerebrospinal fluid B-endorphin levels in Rett syndrome

Cerebrospinal fluid (CSF) levels of B-endorphin (B-EP), B-lipotropin (B-LPH) and ACTH were measured in nine girls with Rett syndrome with features of autistic behavior (3.7-12.1 years of age) and in ten children with chronic leukemia (control group). The peptides were measured by radioimmunoassay, either directly in the sample (ACTH) or after Sephadex G-75 column chromatography, in order to eliminate interfering substances (B-LPH and B-EP). The CSF B-EP patient levels (20.8 +/- 13.1 fmol/ml, means +/- SD) were significantly lower than in age-matched controls (69.1 +/- 32.6, P less than 0.01), whereas the B-LPH and ACTH levels were in the control range. No correlations were found between the clinical findings and CSF neuropeptide concentrations. These data demonstrate a decrease in central opiate activity in girls with Rett syndrome.

Effects of bromocriptine on pituitary and adrenal cortex in pre-adrenarchal rabbits

The effect of bromocriptine on the morphological picture and steroid content of the adrenal gland, and on certain pro-opiomelanocortin (C) peptides in the pituitary gland was evaluated in preadrenarchal rabbits. Eighteen immature male rabbits (5 weeks of age), were treated for 10 days with saline (n = 10,2 ml sc) or bromocriptine mesylate (n = 8, 3 mg/kg sc) two times/day. After the last administration all animals received dexamethasone (0.25 mg im) and the next morning, 60 min after ACTH injection (0.25 mg im), plasma was drawn and they were sacrificed. Adrenals and pituitaries were immediately removed. For each animal, one adrenal gland was fixed, dehydrated and embedded in paraffin for histology; the other one was stored in saline for determination of androstenedione (A), dehydroepiandrosterone (DHA), 17-OH progesterone (17 P), and cortisol. Steroids were analyzed by RIA after previous extraction and celite-ethyleneglycol chromatography, or directly (cortisol). The immunoreactivities (ir) related to beta-Endorphin (B-EP), ACTH and alpha-MSH were evaluated in pituitary homogenates using specific RIAs. The bromocriptine-treated rabbits showed a significant increase in the percentage of the adrenal zona reticularis (21.5 +/- 3.9% of total cortex vs. 12.7 +/- 1.3% in controls, p less than 0.05, mean +/- SE), and a decrease of the zona fasciculata (57.6 +/- 3.13% vs. 67.7 +/- 2.05% in controls, p less than 0.05). No significant changes were observed in the relative percentage of the zona glomerulosa.(ABSTRACT TRUNCATED AT 250 WORDS)

Neuroendocrine evidence of deranged noradrenergic activity in chronic migraine

Migraine is a psychobiological disorder in which a recurrent failure of opioid and adrenergic systems might occur, as plasma and CSF studies suggest. In order to elucidate the relationship between noradrenergic and opioidergic functions, the plasma beta-endorphin (beta-EP) response to clonidine and the cortisol response to dexamethasone were evaluated together in 25 patients suffering from migraine without aura, and with chronic tension headache (MTH). Baseline beta-EP plasma levels and beta-EP response to clonidine were significantly lower in MTH subjects than in controls, suggesting a postsynaptic hypothalamo-pituitary impairment. Forty-four percent of the MTH subjects showed either a lack of suppression of plasma cortisol following dexamethasone administration, or basal cortisol concentrations higher than controls and suppressors, suggesting a disinhibition of the hypothalamopituitary-adrenal (HPA) axis. An inverse correlation was found between pain severity and beta-EP secretion induced by clonidine (delta max), and no relationship was found between beta-EP and mood. These data suggest a failure of central noradrenergic activity, or perhaps an impaired secretion of beta-EP not related to HPA axis hyperactivity or to affective state.

Possible hyperendorphinergic pathophysiology of the Rett syndrome

The Rett syndrome is a postnatal developmental and neurological disorder seen only in girls. Many of the symptoms of this disorder, such as microcephaly, stereotypy, respiratory disturbances and seizures, are analogous to the effects of the administration of beta-endorphin or other opioids in animals. Preliminary reports of elevated beta-endorphin-like immunoreactivity in the cerebrospinal fluid of girls with the Rett syndrome, as well as improvement in some of their symptoms during the administration of the opioid antagonist naltrexone, are suggestive of endorphinergic hyperactivity. Thus, the pathophysiology of the Rett syndrome might involve excessive stimulation of opioid receptors in the central nervous system by beta-endorphin or other endogenous opioids.

N-terminal ACTH fragments increase the CSF beta-EP content in Alzheimer type dementia

Eleven patients with presenile Alzheimer type dementia (ATD) were treated with N-terminal ACTH fragments for 14 days. No change in cognitive functions was observed during the treatment. A significant increase in CSF beta-endorphin (beta-EP) levels was found, while ACTH and beta-lipoprotein remain unaffected. The possibility that ACTH and its moieties could interfere with beta-EP activities in CNS is discussed.

Endocrinology in aging

Aging is a time of reduced adaptability to metabolic perturbation. This is particularly true in endocrinology which, after all, is the science of chemically regulated biologic systems. There is no evidence that equilibrium concentrations of the principal hormones are altered with age. However, the systems utilized to reach those equilibria become progressively taxed, and new equilibria may be achieved reflecting that regulatory problem. Thus, with advancing age there are significant alterations in hormone production, metabolism, and action. Some of these changes may play a role in the pathophysiology of senescence, although the evidence for that is limited. The magnitude of age-related alterations is highly variable and sex dependent. Whereas only subtle changes occur in pituitary dynamics, adrenal gland physiology, and thyroid function, the changes in glucose homeostasis, reproductive function, and calcium metabolism are more apparent. In the elderly, the interpretation of endocrine tests should reflect the nutritional status of the patient and the presence of coexisting illnesses. In this review, we describe the principles of endocrinology in the geriatric population and elaborate on the changes in specific glandular functions with aging. We also define strategies of evaluation and management protocols appropriate for the elderly with suspected endocrine dysfunction.

Neuroendocrine evaluation of central opiate activity in primary headache disorders

The evaluation of central opiate activity could be of clinical value in the diagnosis and treatment of pain syndromes. The current approach via direct measurement of endogenous opioid peptides in cerebrospinal fluid (CSF) is not devoid of side effects and cannot be used in every-day practice. As an alternative to this method, we have studied the neuroendocrine response of plasma LH to an i.v. naloxone injection in 39 headache sufferers from different diagnostic subgroups, and in 12 age- and sex-matched healthy volunteers. Patients (19 females and 20 males) were affected by common migraine (CM, 11 cases), migraine with interparoxysmal headache (MIH, 9), classical migraine (CIM, 9), and chronic cluster headache (CH, 10). Headache lasted 3-36 years. Prior to naloxone challenge (4 mg i.v.), LH pulsatility was evaluated for 1 h. The next morning, the pituitary response to LH-RH (10 micrograms i.v.) was tested in 20 patients. Plasma LH was measured by RIA in every sample. The response to the tests was evaluated as secretion area of plasma LH minus the mean basal value. Controls (497.5 +/- 85.5 mIU/ml x 120 min), ClM (357.8 +/- 78.9) and CH (450.5 +/- 70.4) patients showed similar results, while in cases of CM (155.3 +/- 71.7, P less than 0.05) and MIH (104.1 +/- 53.7, P less than 0.01) the LH secretion after naloxone injection was significantly blunted. On the contrary, the response of LH to LH-RH was similar in controls and patient groups, thus excluding pituitary dysfunctions in this response.(ABSTRACT TRUNCATED AT 250 WORDS)

CSF-endorphines in acute and chronic brain lesions

In order to answer the question of an opioid influence on consciousness, a radio-immuno-assay (n = 852) of beta-endorphin and beta-LPH (beta-lipotropic hormone) in both ventricular CSF and blood plasma was carried out in 101 neurosurgical patients. The following results were obtained: I) beta-END and beta-LPH levels were found to be lower in the CSF than in blood plasma. II) beta-END and beta-LPH in the CSF was the same in both sexes. III) beta-END levels in the CSF decreased with age. IV) beta-END and beta-LPH levels showed a diurnal rhythm with a maximum in the late a. m. hours. V) beta-END levels in the ventricular CSF tend to decrease parallel to a drop in conciousness as well as with longlasting comatous states. VI) beta-END in ventricular CSF becomes higher with increasing systolic arterial blood pressure. VII) beta-END and beta-LPH levels in ventricular CSF are not correlated with the type of the disease, CSF pressure, body temperature or respiratory changes.

Plasma B-endorphin resistance to dexamethasone suppression in obese patients

Patients with simple exogenous obesity are characterized by increased B-endorphin (B-EP) plasma levels, despite normal ACTH and B-Lipotropin (B-LPH). To evaluate the origin of such an hyperendorphinemia, 42 obese patients were submitted to a short overnight dexamethasone suppression test (DST: 1 mg at 23:00 h). Blood samples were taken in basal conditions and 9, and 17 h after DST. The same procedure was applied in 12 healthy, normal weight volunteers. In further five patients, 0.5 mg per 4/die were given. B-EP was measured by radioimmunoassay (RIA) after silicic acid extraction and Sephadex G-75 column chromatography. ACTH and Cortisol were measured by direct IRMA and RIA, respectively. Basal B-EP levels of patients (24.2 +/- 16.5, fmol/ml, M +/- SD) were double than in normal weight controls (10.8 +/- 4.6), while ACTH and cortisol fell in the normal range. ACTH and cortisol were significantly reduced by DST in both patients and controls, while B-EP in patients did not. Cortisol, however, was not suppressed in 7 patients (16%). At 08:00, the suppression of B-EP in controls was 49.0 +/- 18.4%, while in obese patients it was only 21.2 +/- 38.8% (p less than 0.01). However, patients with weight excess below 50% normally suppressed B-EP (41.6 +/- 15.3%), while those with weight excess over 75% did not (11.3 +/- 47.5%). The doubling of dexamethasone intake does not lead to a suppression of plasma B-EP in these last patients. These data indicate the existence of neuroendocrine abnormalities in the hypothalamus-pituitary-adrenal axis of obese patients and suggest that their hyperendorphinemia originates outside the anterior pituitary.

Detection of enkephalin-like immunoreactive material in human saliva

1. A specific radioimmunoassay (RIA) was used to detect the presence of enkephalin-like activity in mixed saliva from healthy male and female human subjects, whose ages ranged from 20 to 30 and from 55 to 65 years. 2. Enkephalin-like immunoreactivity was measured in saliva from all subjects. Within the limits posed by the immunoassay no significant differences in levels were evident among the various groups. 3. The results of this study provide the first demonstration of opioid-like substances in saliva. 4. As the collection of saliva involves non-invasive techniques, this source may prove useful for monitoring enkephalin levels during various clinical procedures or experimental treatments.

Beta-lipotropin is the major component of the plasma opioid response to surgical stress in humans

There is growing experimental evidence that beta-endorphin immunoreactivity is raised by surgical stress in patients undergoing general anesthesia. As the assay methods employed to date did not allow to fully discriminate between beta-endorphin and its immediate precursor, beta-lipotropin, we have investigated in the present study plasma levels of these two peptides by separating them by chromatography on plasma extracts prior to radioimmunoassay in eighteen surgical patients under general anesthesia and eight under spinal anesthesia. Beta-lipotropin, but not beta-endorphin, plasma levels were found to be significantly elevated during surgery in the general anesthesia group, while no change was found in either peptide concentration in the spinal one. Cortisol plasma levels also increased significantly 90 minutes after the beginning of surgery, when they were positively correlated to beta-lipotropin ones. Although the sampling time we adopted may have prevented us from detecting an early peak of beta-endorphin during the first 30 minutes of surgery, the major component of the pituitary opioid response to surgical stress appears to be related to beta-lipotropin. This is in agreement with results of experimental work on various kinds of stress in animals and humans and seems to rule out a role for plasma beta-endorphin in post-operative analgesia.

Proopiomelanocortin-related peptides and methionine enkephalin in human follicular fluid: changes during the menstrual cycle

Several studies indicate the presence of different pituitary hormones or neuropeptides in ovarian follicular fluid from various species. Recently our group showed that the ovarian follicular fluid of health women contains two of the endogenous opioid peptides, beta-endorphin and methionine enkephalin, in concentrations that are tenfold to twentyfold higher than in circulating plasma. The presence of immunoreactive beta-lipotropin was also shown. The aim of the present study was to evaluate whether adrenocorticotropic hormone, which in pituitary cells is synthesized from proopiomelanocortin such as beta-endorphin and beta-lipotropin, is also present in follicular fluid and the possible changes of proopiomelanocortin-related peptides during the menstrual cycle. Concentrations of beta-endorphin, methionine enkephalin, adrenocorticotropic hormone, and beta-lipotropin were measured in 60 healthy menstruating women at different periods of the menstrual cycle (20 during the follicular, 22 in the preovulatory days, and 18 during the luteal phase). Thirteen women participated in an in vitro fertilization program and thus received clomiphene citrate (100 mg/day from the fifth to the ninth day) plus 5000 IU human chorionic gonadotropin before starting the program. All samples were collected at laparoscopy under general anesthesia. In another eight patients fluid was collected from follicular cysts. Peptides were extracted on octadodecasilyl silica columns with 80% methanol in 0.5 mol/L acetic acid. The identity of follicular fluid beta-endorphin, methionine enkephalin, adrenocorticotropic hormone, and beta-lipotropin and standard peptides was demonstrated with high-pressure liquid chromatography. Peptide concentrations were measured in extracts by radioimmunoassays either directly by (methionine enkephalin and adrenocorticotropic hormone) or after (beta-endorphin and beta-lipotropin) gel filtration on Sephadex G-75. The concentrations of methionine enkephalin, adrenocorticotropic hormone, and beta-lipotropin were similar in the different periods of the cycle. Conversely, beta-endorphin concentrations were significantly higher in preovulatory days than in the other periods; no differences were evident between spontaneous and stimulated cycles. These results indicate that proopiomelanocortin-related peptides are present in the follicular fluid and that beta-endorphin concentrations change during the menstrual cycle, with the highest values occurring in the preovulatory follicle.

No gradient exists between lumbar and ventricular cerebrospinal fluid beta-endorphin

In 8 patients, beta-lipotropin (beta-LPH), beta-endorphin (beta-EP), ACTH, protein and chloride concentrations were measured in cerebrospinal fluid (CSF) samples obtained simultaneously from the lumbar space and lateral ventricle. Albumin and IgG levels were significantly higher in lumbar than in ventricular CSF samples while no craniocaudal gradient was observed for neuropeptide concentrations. The importance of molecular weight in determining such a regional distribution is supported also by the similar lumbar and ventricular levels of chlorides. These data would validate the CSF approach through lumbar puncture as a tool for exploring neuropeptides in the central nervous system.

Premenstrual fall of plasma beta-endorphin in patients with premenstrual syndrome

Plasma beta-endorphin (beta-EP), beta-lipotropin (beta-LPH), and cortisol concentrations were measured by perimenstrual period in 11 patients affected by premenstrual syndrome (PMS) and in 8 asymptomatic healthy volunteers. Blood samples were collected every 2 to 3 days, for 1 month, starting from midcycle. The Menstrual Distress Questionnaire (MDQ) was administered during the testing period. Plasma beta-LPH and cortisol levels remain stable during the perimenstrual period, in both controls and PMS patients. On the contrary, PMS patients showed a decrease of plasma beta-EP in the week preceding menses and during the first days of menstrual flow. Beta-EP values of PMS patients regain normal levels during the next follicular phase. No changes of beta-EP levels were recorded in asymptomatic women. MDQ scores revealed that PMS patients complained of water retention, pain discomfort, and mood swings. The transient and reversible decrease of plasma beta-EP in PMS patients near to and at menses remains to be clarified.

Effects of Org OD 14 on pituitary and peripheral beta-endorphin in castrated rats and post-menopausal women

The aim of the first part of this study was to evaluate the effects of a new synthetic steroid (7 alpha,17 alpha)-17-hydroxy-7-methyl-19-norpregn-5(10)-en-20-yn-3-one (Org OD 14), on anterior pituitary (AP) and neurointermediate pituitary lobe (NIL) contents and on circulating levels of beta-endorphin (beta-EP) in rats. Three weeks after ovariectomy, groups of 9 rats were treated with either Org OD 14 (2 or 10 micrograms/day/rat for 14 days) or a placebo. In addition, 2 groups of ovariectomized rats were also treated with oestradiol benzoate (EB) (2 or 10 micrograms/day/rat for 14 days) to compare the effectiveness of the new steroid with that of a classical oestrogenic substance. beta-Ep concentrations were measured in plasma and in AP and NIL extracts by means of double-antibody radioimmunoassay (RIA), employing a specific anti-camel beta-EP (C-terminal fragment). Both doses of Org OD 14 induced a significant dose-related increase in plasma and pituitary lobe beta-EP concentrations as compared with the results on placebo treatment. By comparison, EB was active only at a dose of 10 micrograms/day. Despite the common stimulatory effects of EB and Org OD 14 on pituitary beta-EP, these findings suggest that the two steroids have different modes of action. The second part of the study investigated the changes in beta-EP and beta-lipotrophin (beta-LPH) plasma levels in a group of post-menopausal women treated for 6 months with Org OD 14 (2.5 mg/day) in comparison with the levels in a placebo-treated group. The clinical efficacy of Org OD 14 treatment in post-menopausal symptoms was confirmed, as well as its lack of or only transient effect on plasma lipids and lipoproteins. beta-EP and beta-LPH plasma levels were significantly higher in the Org OD 14-treated group than in the placebo group as from the second month until the end of the observation period.

Dissociation between CSF and plasma B-endorphin in major depressive disorders: evidence for a different regulation

Plasma and cerebrospinal fluid (CSF) levels of ACTH, B-lipotropin (B-LPH) and B-endorphin (B-EP) were simultaneously measured in 10 patients with major depression (35-57 yr) with a disease history of 10-34 yr, 7 of them with recurrent episodes, and in 13 age-matched healthy controls. In patients, lumbar puncture was performed after a 10 days drug-free period. Plasma B-EP and B-LPH levels were measured by RIA after silicic acid plasma extraction and Sephadex G-75 column chromatography. Plasma ACTH concentrations were measured by IRMA. For CSF assays the extraction step was avoided. In depressed patients, plasma ACTH (16.2 +/- 6.9 fmol/ml, mean +/- SD), B-LPH (19.8 +/- 8.5) and B-EP (17.8 +/- 7.0) levels were significantly higher (p less than 0.01) than in controls. On the contrary, CSF levels of the three peptides were similar in the two groups. No correlations were found between plasma or CSF concentrations and duration of the disease or severity of the actual episode. These data add further evidence to the independent regulation between central and peripheral POMC-related peptides. They also reduce the possibility that peptides of pituitary origin, directly from the gland or through the peripheral circulation, could penetrate the CSF.

CSF and plasma levels of pro-opiomelanocortin-related peptides in reversible ischaemic attacks and strokes

Plasma and CSF beta-endorphin (beta-EP), beta-lipotropin (beta-LPH) and ACTH levels were studied in a group of 25 patients who underwent reversible ischaemic attacks or completed strokes. CSF beta-EP and beta-LPH in ischaemic patients were higher than those of the control population, independently of both clinical reversibility of the cerebral damage, and the time lapse sampling and the acute event. The presence of a CT demonstrable lesion was related to the highest CSF beta-EP levels. These data confirm an involvement of central opioid substances in the phenomena related to brain ischaemia. ACTH levels in the CSF did not differ from the controls; this finding further supports the concept of an independent central secretion of the different pro-opiomelanocortin-related peptides. The peripheral plasma concentrations of beta-EP, beta-LPH and ACTH, were, in contrast, within the normal range, confirming that CSF and plasma contents of pro-opiomelanocortin-related peptides are differently controlled and originate from different sources.

Reduced ACTH content in cerebrospinal fluid of children affected by cryptogenic infantile spasms with hypsarrhythmia

In view of the therapeutic efficacy of adrenocorticotropic hormone (ACTH) in the treatment of infantile spasms (IS) with hypsarrhythmia, we studied the cerebrospinal fluid (CSF) levels of ACTH in 15 children (4-10 months) affected by IS with hypsarrhythmia (eight cryptogenic forms, seven secondary to perinatal distress) and in age-matched controls. Lumbar puncture was performed in all but one case before any kind of treatment. In another case, CSF was collected 3 weeks after a spontaneous remission. Both ACTH and beta-endorphin (beta-EP), the other peptide related to the same precursor (proopiomelanocortin), were measured by specific radioimmunoassay after gel chromatography. While beta-EP levels were unchanged in the two groups of patients, ACTH concentrations of cryptogenic (3.75 +/- 2.40 fmol/ml, Mean +/- SD p less than 0.05) and secondary (6.36 +/- 3.70, NS) forms were lower than in controls (10.90 +/- 5.79). On the other hand, ACTH was higher in the case studied after therapy (9.0) and in the case presenting a spontaneous clinical and EEG remission (15.0). These data indicate that in children affected by IS with hypsarrhythmia (mainly of cryptogenic type), CSF levels of ACTH are lower, while levels of beta-EP remain normal. It would therefore appear that central ACTH content may play a possible role in the pathogenesis of IS with hypsarrhythmia.

Reduced ACTH, while normal beta-endorphin CSF levels in early epileptic encephalopathies

Since ACTH and the opioids display opposite effects on experimentally-induced seizures, cerebrospinal fluid (CSF) levels of ACTH and beta-endorphin (beta-EP) were measured in 6 children (4-8 months) affected by infantile spasms with hypsarhythmia, an idiopathic early onset encephalopathy, and in 8 age-matched controls. beta-EP levels in the patients (76.3 +/- 14.7 fmol/ml, M +/- SD) did not differ from those in controls (109.8 +/- 42.7) while babies with epileptic encephalopathy showed reduced ACTH levels in the CSF (3.8 +/- 1.5) as compared to controls (9.0 +/- 3.7, p less than 0.01). This resulted in an increased beta-EP/ACTH ratio. Another patient previously treated with ACTH showed a normal CSF level of ACTH (9.0) with a normal beta-EP/ACTH ratio while in clinical and EEG remission. These results are consistent with the hypothesis that some infantile seizures unrelated to brain injuries could originate from an ACTH deficiency at central level and/or an imbalance of neuropeptidergic pathways.

Central ACTH deficit in degenerative and vascular dementia

Cerebrospinal fluid (CSF) concentrations of ACTH, beta-lipotropin (beta-LPH) and beta-endorphin (beta-EP) were measured in 15 patients affected by dementia, who underwent also a brain computerized tomography (CT), and in 13 age-matched healthy volunteers. ACTH CSF levels of patients (4.0 +/- 2.4 fmol/ml, M +/- SD) were significantly lower than in controls (9.8 +/- 5.0, P less than 0.01) the lowest values being found in Alzheimer type of dementia (ATD: 3.1 +/- 2.5) and in patients with radiological evidence of cortical atrophy (2.5 +/- 1.2), independently of the probable origin of dementia. Although beta-LPH and beta-EP levels of patients fell within normal range, they were lower in ATD than in dementia sustained on a vascular origin. There was no variation of either peptides concentration in relation to CT findings. These data indicate the ACTH impairment as typical of dementia, supporting in humans the positive role of this peptide on learning and mnesic functions. Moreover, the maintained CSF levels of both beta-LPH and beta-EP in the dementia sustained on a vascular origin, while lower values were found in ATD, could represent a differentiation between vascular and degenerative diseases of the Central Nervous System (CNS).

Concomitant increase in nociceptive flexion reflex threshold and plasma opioids following transcutaneous nerve stimulation

In order to evaluate the role of endogenous opioids in sustaining analgesia induced by transcutaneous nerve stimulation (TNS), we measured plasma beta-lipotropin (BLPH), beta-endorphin (BEP), ACTH and cortisol changes concomitantly with nociceptive flexion reflex (RIII) threshold after TNS (80 microseconds rectangular waves at 85 Hz) in a group of healthy volunteers (A). The same protocol was carried out in another group of volunteers using placebo stimulation (0.5 Hz) (B). RIII threshold significantly increased 0.5 h after TNS in group A and no changes were recorded in group B. Similarly, both BLPH and BEP plasma levels increased at the end of TNS only in group A. ACTH and cortisol concentrations show only random variations after both high and low frequency TNS. A positive linear correlation was found between the maximum percentage increase of RIII threshold after high frequency TNS and the maximum percentage increase of BLPH plasma levels occurring 20 min beforehand (r = 0.856, P less than 0.001). A less positive correlation was found between RIII and BEP levels (r = 0.574, P less than 0.05). These data indicate that the so-called post-stimulation analgesia could be supported by the enhancement of the endogenous opioid system.