Tumor necrosis factor alpha differentially regulates beta-endorphin concentrations and proopiomelanocortin RNA in the anterior and neurointermediate pituitary in vivo

We analyzed the effect of tumor necrosis factor alpha (TNF-alpha) on beta-endorphin concentrations and proopiomelanocortin mRNA in the rat anterior and neurointermediate pituitaries. The intraperitoneal injection of 5 micrograms/kg TNF-alpha decreases beta-endorphin in neurointermediate pituicytes 4, 8 and 24 h after the treatment without affecting proopiomelanocortin (POMC) RNA. In contrast, in the anterior pituitary 4 h after the injection of the cytokine, POMC RNA was decreased while the peptide content was increased. These effects can be relevant to the modulation of the pituitary-adrenal axis and immune responses in conditions, such as infections, in which TNF levels are increased.

Plasma interleukin-1 beta concentrations in panic disorder

Plasma interleukin-1 beta (IL-1 beta) concentrations were measured in 10 outpatients with panic disorder before and on days 30 and 32 of treatment with alprazolam (2-2.5 mg/day). IL-1 beta concentrations were found to be significantly higher in patients than in control subjects both before and during therapy. Thus, IL-1 beta levels may be a marker of panic disorder that is not related to the current level of symptomatology.

Veralipride for hot flushes induced by a gonadotropin-releasing hormone agonist: a controlled study

OBJECTIVES

To evaluate the efficacy of veralipride, a benzamide derivative, in the treatment of hot flushes induced by GnRH agonists (GnRH-a) and to study peripheral blood mononuclear cell beta-endorphin concentrations during drug administration.

DESIGN

Randomized, placebo-controlled, double-blind trial.

SETTING

Academic department of obstetrics and gynecology.

PATIENTS

Forty women of mean age 43 +/- 5 years who experienced disturbing hot flushes during a 4-month course of tryptorelin depot for myoma-associated menorrhagia.

INTERVENTIONS

Treatment with oral veralipride 100 mg/d (20 subjects) or matching placebo (20 subjects) during the third month of GnRH-a administration.

MAIN OUTCOME MEASURES

Modifications of frequency and severity of hot flushes as shown by a 0 to 6-point vasomotor scoring system and variations of beta-endorphin levels in peripheral blood mononuclear cells.

RESULTS

Two subjects in each group dropped out of the study. The median (range) vasomotor score at the end of the second month of treatment was 4 (3 to 6) in both the veralipride and placebo group. At the end of the third and fourth months the median (range) scores were, respectively, 2 (0 to 6) versus 4 (1 to 6) and 2 (0 to 5) versus 4 (1 to 6). No significant variations in mononuclear cell beta-endorphin concentrations were recorded. Serum PRL levels rose from 11.7 +/- 5.7 to 132.3 +/- 65.0 ng/mL (conversion factor to SI unit, 1.0) during veralipride administration and returned to 10.6 +/- 3.7 ng/mL after drug withdrawal.

CONCLUSION

Veralipride reduced vasomotor symptoms induced by a GnRH-a. Transient hyperprolactinemia was the main side effect observed. The mode of action of the drug in GnRH-a-treated patients and possible interactions with endogenous opioid peptides need further elucidation.

Intracerebroventricular interleukin-1 alpha increases immunocyte beta-endorphin concentrations in the rat: involvement of corticotropin-releasing hormone, catecholamines, and serotonin

The opioid peptide beta-endorphin (BE) is synthesized and secreted by the cells of the immune system and has been shown to participate in the modulation of immune responses, e.g. during stress. Interleukin-1 (IL-1) is a potent activator of the corticotropin-releasing hormone (CRH) system in the hypothalamus, and it has been shown to be involved in many stress responses, including immunosuppression. We studied the effect of centrally injected IL-1 alpha on immunocyte BE concentrations in the rat. IL-1 alpha (1 ng/rat, intracerebroventricularly) significantly (P < 0.01) increased the concentrations of the peptide in splenocytes, lymph node cells, and peripheral blood mononuclear cells 2 and 24 h after treatment. Intracerebroventricular, but not iv, administration of 2 micrograms IL-1 receptor antagonist blocked the IL-1 alpha-induced increase. These effects were also prevented by the intracerebroventricular administration of the CRH receptor antagonist alpha-helical CRH-(9-41). Treatment with 6-hydroxydopamine and 5,7-dihydroxytryptamine, which deplete the catecholaminergic or the serotoninergic systems, respectively, blocked the increase in BE induced by the cytokine. In contrast, hypophysectomy and treatment with indomethacin did not modify the effect of IL. The increase in immunocyte BE, therefore, seems to depend on the activation of CRH, catecholamines, and serotonin, but to be independent of activation of the hypothalamus-pituitary-adrenal-axis and prostaglandins. The immunocyte BE increase could be involved in the immunosuppression induced by central IL-1 alpha.

Fluoxetine reduces inflammatory edema in the rat: involvement of the pituitary-adrenal axis

The acute effect of the non-tricyclic, pro-serotoninergic, antidepressant drug fluoxetine on inflammatory edema was evaluated in the rat. Fluoxetine significantly and dose dependently reduced the swelling induced by the injection of 10% brewer's yeast suspension in the hindpaw. Both adrenalectomy and hypophysectomy prevented the effect of fluoxetine. In contrast pretreatment with the corticotropin-releasing hormone antagonist alpha-helical CRH-(9-41) did not interfere with the anti-inflammatory action of fluoxetine. Moreover, the drug induced a significant increase of corticosterone plasma concentrations in vivo, whereas, in vitro, it did not stimulate beta-endorphin release from anterior pituitary cells. Our data suggest that fluoxetine exerts a potent anti-inflammatory action by inducing pituitary-adrenocortical activation via serotonin.

Decreased beta-endorphin content in peripheral blood mononuclear leukocytes from patients with Crohn's disease

Increased activation of lymphocytes in inflammatory bowel disease is reflected by alterations of various immunological functions including enhanced spontaneous secretion of rheumatoid factor by mononuclear cells. since in rheumatic diseases increased secretion of rheumatoid factor is associated with decreased levels of beta-endorphin in circulating blood mononuclear leukocytes, we investigated levels of leukocyte beta-endorphin in inflammatory bowel disease and compared them with those in hepatobiliary disorders and in healthy subjects. Levels of beta-endorphin were measured in extracts from peripheral blood mononuclear leukocytes by radioimmunoassay. beta-Endorphin levels ranged from 0 to 67 pg/10(6) cells. Mononuclear leukocytes from ulcerative colitis patients contained as much beta-endorphin as those from healthy control subjects. In patients with Crohn's disease, levels of beta-endorphin were reduced by as much as roughly 50%. An inverse relationship was found between leukocyte beta-endorphin on the one hand and erythrocyte sedimentation rate, blood granulocyte or thrombocyte counts, and C-reactive protein levels in plasma on the other. In patients with various hepatobiliary disorders including fatty liver disease, viral hepatitis, primary biliary cirrhosis, and cryptogenic or alcoholic cirrhosis, beta-endorphin levels were not significantly different from the normal range values. Data indicate that leukocyte beta-endorphin may be involved in regulation of the systemic inflammatory activity of Crohn's disease.

Intermittent but not continuous inescapable footshock stress affects immune responses and immunocyte beta-endorphin concentrations in the rat

It is well known that a variety of stressors influence immune responses. The opioid peptide-beta-endorphin (BE) is deeply involved in stress responses, is synthesized in cells of the immune system, and participates in the modulation of immune function. We analyzed the ability of two different stress paradigms to modulate the beta-endorphin concentrations in the immune cells and the immune response in the rat. Two and 24 h after the exposure to inescapable intermittent footshock (1.6 mA, 60 Hz, 1 s, every 5 s for 20 min) the concentrations of beta-endorphin in splenocytes, peripheral blood mononuclear cells and lymph node cells were significantly increased. In contrast, the exposure to a continuous footshock for 3 min did not affect the concentrations of the opioid peptide. Similarly, phytohemoagglutinin-induced proliferation of splenocytes and natural killer activity were significantly impaired only after the exposure to intermittent footshock stress. On the contrary, plasma corticosterone levels were similarly elevated after both paradigms of stress. The pretreatment with the corticotropin-releasing hormone (CRH) receptor antagonist prevented both the stress-induced increase of immunocyte BE and immunosuppression. In conclusion, our data suggest that intermittent and continuous footshock stressors activate different neuroendocrine responses and that CRH plays a central role in mediating the immune effects of the intermittent footshock stress. The possible relationship between the beta-endorphin changes and immunosuppression is discussed.

Chlomipramine differently affects inflammatory edema and pain in the rat

In the rat, the acute administration of the antidepressant drug chlomipramine significantly reduces the edema and the hyperalgesia induced by yeast injection in the paw. However, the intensity and time course of the two effects differ. Moreover, adrenalectomy enhances the antinociceptive effect, whereas it does not affect the antiedema action of chlomipramine. Our data suggest a dissociation between the antiinflammatory and the analgesic effect of acute chlomipramine.

Chlorimipramine and nortriptyline but not fluoxetine and fluvoxamine inhibit human polymorphonuclear cell chemotaxis in vitro

We examined the ability of antidepressant drugs belonging to different classes to interfere with human polymorphonuclear cell migration in vitro. 1. The tricyclic antidepressant drugs chlorimipramine and nortriptyline were able to block, in a dose related fashion both spontaneous and formyl-methionyl-leucyl-phenylalanine stimulated migration. This effect was already evident at very low concentrations (10(-7)M). 2. The atypical non-tricyclic antidepressant drugs fluoxetine and fluvoxamine did not affect polymorphonuclear cell mobility. 3. The ability of antidepressant drugs to interfere with polymorphonuclear cell physiology seems to depend on their chemical structures.

Beta-endorphin concentrations in brain areas and peritoneal macrophages in rats susceptible and resistant to experimental allergic encephalomyelitis: a possible relationship between tumor necrosis factor alpha and opioids in the disease

Since the central nervous system and neuropeptides modulate immune functions, we investigated whether the different susceptibility of Lewis and Brown Norway rats to experimental allergic encephalomyelitis could also reflect differences in beta-endorphin and substance P concentrations in brain areas and macrophages during the development of the disease. We show that beta-endorphin concentrations increase much more in the hypothalamus and macrophages of Lewis rats during the development of the disease, while the increase is much lower or absent in Brown Norway rats. Tumor necrosis factor-alpha seems to play an important role in this difference. The administration of the opiate receptor antagonist naltrexone worsens the development of the disease, suggesting that the increase of the opioid beta-endorphin might represent a mechanism to downregulate the immune response. In both strains, the concentrations of substance P do not change.

Beta-endorphin content in HIV-infected HuT78 cell line and in peripheral lymphocytes from HIV-positive subjects

We investigated beta-endorphin (BE) content in an HIV-infected cell line and in peripheral blood mononuclear cells (PBM) from HIV-positive subjects. HIV infection increased BE content in HuT78 cell line compared to uninfected cells. Accordingly, BE content was greater in HIV-positive subjects than in healthy controls, both in fresh PBM and in mitogen-stimulated or unstimulated cultured cells. Further, in PHA-stimulated cultures, BE increase was correlated with disease progression. Opioids are known to decrease immune responsiveness in vivo, and it may be that the increased BE concentrations contribute to HIV-associated immune deficiency. In HIV-positive subjects, but not in healthy controls, intracellular BE concentration was positively correlated with PHA-induced PBM proliferation. The latter data suggest an alternative explanation: that the increased BE content represents a paradoxical response of the host in an attempt to balance virus-induced immunodepression. Thus, BE may be important in fine-tuning of the immune response with its up- and downregulation dependent upon differences in immune status.

Cloned microglial cells but not macrophages synthesize beta-endorphin in response to CRH activation

The properties of microglial cell clones, obtained from embryonic mouse brain primary cultures immortalized with recombinant retroviruses, have been investigated and compared with the properties of macrophage clones similarly obtained. Macrophage clones differed from microglial clones in some functions but shared most of the immunological properties. Interestingly, microglial cells were able to produce beta-endorphin, and this production was regulated differently in microglial cell clones when compared with macrophages clones. Although lipopolysaccharide (LPS) treatment induces an increase in beta-endorphin concentration in both cell types, only microglial clones and primary microglial cell cultures respond to the neuroendocrine stimulus corticotropin releasing hormone (CRH). In addition, in these cells, beta-endorphin release is regulated by a classical neurotransmitter, such as noradrenaline, adding some evidence of communication between neurons and microglial cells.

Beta-endorphin levels are reduced in peripheral blood mononuclear cells of cluster headache patients

Opioid system hypofunction has been postulated in cluster headache (CH) on the basis of reduced opioid levels found in the cerebrospinal fluid (CSF). In this study beta-endorphin levels were monitored in the peripheral blood mononuclear cells of 65 episodic CH patients (32 in remission and 33 in cluster period) and 50 healthy controls. Beta-endorphin levels were significantly lower than controls in CH patients experiencing both phases of the illness (ANOVA, p < 0.0001). The persistence of this abnormality during pain-free remission suggests a primary alteration in the regulation of beta-endorphin in peripheral blood mononuclear cells. We speculate that these findings reflect reduced CNS levels of beta-endorphin in CH.

Effect of ibuprofen and diclofenac on the chemotaxis induced by substance P and transforming growth factor-beta on human monocytes and polymorphonuclear cells

The neuropeptide substance P and the cytokine transforming growth factor-beta are potent chemotactic factors for monocytes or polymorphonuclear cells. They are present in synovial fluid of arthritic patients, and participate in the pathogenesis of arthritis. We investigated, in vitro, the effect of two non-steroidal anti-inflammatory drugs, ibuprofen and diclofenac, on the chemotactic effect of substance P and transforming growth factor-beta at concentrations that can be present in the synovial fluid of arthritic patients. Both drugs decrease the chemotaxis induced by substance P and transforming growth factor-beta, at concentrations that can be easily reached in the synovial fluid during therapy. This event could be involved in the effect of some non-steroidal anti-inflammatory drugs on the development and progress of arthritic disease.

Lymphocyte cholecystokinin concentrations in panic disorder

Since cholecystokinin (CCK) is known to be anxiogenic in experimental animals and to induce panic attacks in humans, lymphocyte CCK-8 concentrations were measured in 15 patients with panic disorder and 15 age- and sex-matched healthy subjects. The patients' levels were measured again after a 30-day course of alprazolam therapy, 1.5 mg/day. The CCK-8 concentrations were significantly lower in the patients than in the control subjects and did not change after alprazolam therapy. There was no correlation between the peptide values and levels of anxiety or frequency and severity of panic attacks.

Evidence for an opioid inhibitory effect on T cell proliferation

The proliferative response of human or rat T lymphocytes to phytohemagglutinin (PHA) or concanavalin A (ConA) was measured after acute (30 min) or chronic (8 days) treatment with the opiate receptor antagonists naloxone or naltrexone. Both in the rat and in the human, proliferation was significantly enhanced by acute treatment with the opiate receptor antagonists. In contrast, after chronic treatment proliferation always decreased. The sudden removal of an opioid inhibitory tone might be the basis for the increased proliferative responses observed after acute treatment. The decrease after chronic treatment could be ascribed to the amplification of the inhibitory effect of endogenous opioids due to the up-regulation of opiate receptors that follows chronic antagonist administration. Receptor binding studies of beta-endorphin receptors on splenocytes of chronically naloxone treated rats confirmed this hypothesis: a higher number of beta-endorphin receptors were expressed on splenocytes of naloxone-treated rats compared to controls (Bmax = 9.8 x 10(-12) vs. 1.16 x 10(-12), respectively).

Psychoimmunoendocrine investigation in anorexia nervosa

Immunological and neuroendocrine parameters were examined in 11 women with anorexia nervosa, 6 restricted and 5 bulimic-anorectics, 17-43 years old with 2-15 years duration of the disease, and in 11 age- and sex-matched psychophysically healthy controls. The T lymphocyte proliferative response to phytohemagglutinin (PHA), plasma adrenocorticotropic hormone (ACTH), cortisol and beta-endorphin (beta-EP) levels was examined in basal conditions and after corticotropin-releasing hormone (CRH) stimulation. Cortisol inhibition by dexamethasone (DST), and basal growth hormone (GH) and prolactin (PRL) levels were also examined. The immune study did not reveal significant differences between patients and controls. ACTH and cortisol basal levels were significantly higher in anorectics, while beta-EP, GH and PRL concentrations did not differ in the two groups. ACTH, beta-EP and cortisol responses to CRH were blunted in anorectics and the DST impaired in 55% of the patients. No correlations were observed between neuroendocrine impairments and the T lymphocyte response to PHA, or between the immunological neuroendocrine parameters and the body mass index of either patients or controls.

Brain and gut neuropeptides in peripheral blood mononuclear cells

Neuropeptides, initially thought to be common features of gut and brain, are only synthesized in immune cells and modulate immune functions. The presence and possible functions of these peptides in immune cells in both physiological or pathological conditions have been investigated in our laboratory in the last years. Some of the data obtained are reviewed here, and future developments of the field are indicated.

Benzodiazepine induced chemotaxis of human monocytes: a tool for the study of benzodiazepine receptors

Different ligands of both the "peripheral" and the "central" benzodiazepine receptors were tested for their ability to induce human monocyte chemotaxis. Only the ligands interacting with the "peripheral receptor" (diazepam and Ro 5-4864) were active, and their action was blocked by the specific antagonist PK 11-195, but not by the calcium channel blocker nimodipine. As expected, GABA did not stimulate chemotaxis and it did not modulate the chemotaxis induced by other benzodiazepine receptor ligands. The benzodiazepine inverse agonists FG 7142 and Ro 15-3505 were inactive on chemotaxis when given alone, but they enhanced the "peripheral" ligand induced chemotaxis. This effect was blocked by an agonist and an antagonist of the "central" receptor. These results suggest an interaction between the two different classes of benzodiazepine receptors on human monocytes.

Central effects of tumor necrosis factor alpha and interleukin-1 alpha on nociceptive thresholds and spontaneous locomotor activity

To extend the knowledge on the central effects of cytokines, we studied the effects of tumor necrosis factor alpha and interleukin-1 alpha on nociceptive thresholds and spontaneous locomotor activity in rats. After central administration, both tumor necrosis factor alpha and interleukin-1 alpha significantly (P < 0.001) increase the nociceptive thresholds as measured by the hot-plate test. Tumor necrosis factor alpha, but not interleukin-1 alpha decreases spontaneous locomotor activity evaluated by the Animex test. The increase in nociceptive thresholds induced by tumor necrosis factor alpha or interleukin-1 alpha is not affected by the opiate receptor antagonist naloxone, or antisera against the endogenous opioids beta-endorphin, met-enkephalin or dynorphin. The analgesic effect of tumor necrosis factor alpha is completely antagonized by anti-IL-1 antibodies. Moreover, the cyclooxygenase inhibitor indomethacin does not antagonize the increase of nociceptive thresholds induced by either cytokine.

Beta-endorphin concentrations in resting peripheral mononuclear cells and after treatment with PHA or serotoninergic drugs in human aging, Alzheimer's disease, and Down's syndrome

We measured the concentrations of beta-endorphin in resting peripheral blood mononuclear cells obtained from normal subjects of different ages and from age-matched patients with Down's syndrome or Alzheimer's disease. We also measured beta-endorphin concentrations in peripheral blood mononuclear cells obtained from subjects of different ages after treatment with PHA or serotoninergic drugs. The results show that in normal subjects the concentrations of the peptide increase after 30 years of age and remain constant up to 99 years. After stimulation with PHA, the release of beta-endorphin in cells from subjects older than 30 years increases, leading to a decrease in contents, whereas it is unchanged in younger subjects. In patients with Down's syndrome or Alzheimer's disease, beta-endorphin concentrations in peripheral blood mononuclear cells behave similarly to those in age-matched normal subjects. Treatment in vivo with the serotoninergic agonist chlorimipramine induces an increase in beta-endorphin concentrations in peripheral blood mononuclear cells that is significantly greater in subjects over 30 years old than in younger subjects.

Beta-endorphin concentrations in the peripheral blood mononuclear cells of migraine and tension-type headache patients

Levels of beta-endorphin in peripheral blood mononuclear cells have been studied as a new approach to investigating opioid tone in migraine and tension-type headache. Sixty-one patients with migraine without aura, 39 with migraine with aura and 23 with episodic tension-type headache were compared with 37 healthy controls. Peripheral blood samples were taken from patients not enduring headache attacks and not undergoing prophylactic treatment. A significant reduction in peripheral blood mononuclear cell beta-endorphin concentrations was observed in migraine patients with and without aura, but not in tension-type headache patients. Altered transmitter modulation to peripheral blood mononuclear cells may be the cause of this alteration, which could be part of a more diffuse opioid system derangement in migraine subjects.

Mononuclear cell beta-endorphin concentration in women with and without endometriosis

Seventy-five consecutive patients undergoing laparoscopy for chronic pelvic pain and/or infertility were studied to test whether beta-endorphin concentrations in peripheral mononuclear cells differed according to the presence or absence of endometriosis. Endometriosis was diagnosed in 45 subjects (minimal in 24, mild in 11, moderate in four, and severe in six). Twenty-eight women (62%) with endometriosis and ten (33%) without the disease reported moderate or severe pelvic pain. beta-Endorphin levels were lower in the endometriosis group than in the controls (16.6 +/- 11.2 versus 21.9 +/- 10.5 pg/10(6) cells; P less than .01). This decrease was attributable to reduced beta-endorphin concentrations in the endometriosis patients with moderate or severe pain compared with symptomatic controls (15.5 +/- 10.0 versus 26.3 +/- 7.0 pg/10(6) cells; P less than .01). A significant difference was also found in relation to the cycle phase: The opioid concentration was reduced in the luteal phase in the endometriosis group compared with controls (14.4 +/- 8.4 versus 23.8 +/- 7.5 pg/10(6) cells; P less than .01), but no differences were demonstrated in the follicular and periovulatory phases. beta-Endorphin is capable of modulating the immune response and can be considered as a classical cytokine. Low beta-endorphin production during the luteal phase may have implications in the development and/or maintenance of endometriosis.

Beta-endorphin, vasoactive intestinal peptide and cholecystokinin in peripheral blood mononuclear cells from healthy subjects and from drug-free and haloperidol-treated schizophrenic patients

Beta-endorphin, cholecystokinin and vasoactive intestinal peptide were measured in peripheral blood mononuclear cells of healthy controls, and schizophrenic patients at the first diagnosis before any treatment and after 2 or 15 d of treatment with haloperidol. Beta-endorphin concentrations were similar in controls and untreated patients, and increased with treatment. Cholecystokinin concentrations were higher in patients than in controls, and decreased during treatment. Vasoactive intestinal peptide was lower in patients and did not change with treatment. These observations are consistent with measurements of the same peptides in autopsy samples or cerebrospinal fluid. Peripheral blood mononuclear cells might be an useful tool for the study of some neuropeptides in brain.

Decreased immunoreactive beta-endorphin in mononuclear leucocytes from patients with rheumatic diseases

The neuroendocrine polypeptide hormone beta-endorphin (beta-END), which is released from various tissues including the anterior pituitary gland and cells of the immune system, has recently been implicated as having an immunoregulatory role. We used a radioimmunoassay to measure beta-END levels in circulating mononuclear leucocytes from normal subjects and patients with various rheumatic diseases. Levels of beta-END in leucocytes from patients were lower than in leucocytes from healthy subjects (P less than 0.001). Whereas levels of beta-END in leucocytes from patients with the various rheumatic disorders were not significantly different, an inverse correlation was found between beta-END levels in leucocytes and expression of rheumatoid factor (P less than 0.025) and erythrocyte sedimentation rate (P less than 0.025). This study demonstrates decreased content of beta-END in cells of the immune system related to parameters of inflammatory activity in rheumatic diseases.

Catecholamine and serotonin depletion from rat spinal cord: effects on morphine and footshock induced analgesia

Using a methodology that causes a selective degeneration of spinal cord catecholaminergic or serotoninergic pathways but not those of the brain, it has been possible to study more precisely the role played by the spinal cord monoaminergic systems that underly the mechanism through which morphine and endogenous opioids modulate nociceptive inputs. Both noradrenaline (NA) and serotonin (5-HT) appear to be involved: first, the noradrenergic and only subsequently, with higher doses of the opiate, the serotoninergic pathways.

Psychoimmunoendocrine aspects of panic disorder

Immunological, neuroendocrine and psychological parameters were examined in 14 psychophysically healthy subjects and in 17 panic disorder patients before and after a 30-day course of alprazolam therapy. T lymphocyte proliferation in response to the mitogen phytohemagglutinin, lymphocyte beta-endorphin (beta-EP) concentrations, plasma ACTH, cortisol and beta-EP levels were examined in basal conditions and after corticotropin-releasing hormone (CRH) stimulation. Cortisol inhibition by dexamethasone (DST) and basal growth hormone (GH) and prolactin levels were also examined. Depression, state or trait anxiety, anticipatory anxiety, agoraphobia, simple and social phobias, severity and frequency of panic attacks were monitored by rating scales. The immune study did not reveal any significant difference between patients and controls, or any effect of alprazolam therapy. The hormonal data for the two groups were similar, except for higher than normal basal ACTH and GH plasma levels, lower than normal ratios between the ACTH and cortisol responses to CRH, and blunted DST in some patients. All the impairments improved after alprazolam therapy, in parallel with decreases in anxiety and in severity and frequency of panic attacks.

Age-related changes of beta-endorphin and cholecystokinin in human and rat mononuclear cells

Beta-endorphin (BE) and cholecystokinin (CCK) were measured in fresh PBMC isolated from human subjects and rats. The BE and CCK PBMC contents increased significantly with age both in human and rat models. Moreover, polyclonal stimulation induced a significant decrease of BE but not CCK contents in mononuclear cells from human aged subjects. The time course of changes in BE and CCK concentrations observed in fresh and cultured cells from subjects of different ages did not directly correlate to the time course of age-associated impairment of lectin-induced lymphocyte proliferative response and interleukin-2 synthesis. In fact, the lymphocyte functional defects were significantly observed only in the 71-99 year age group, whereas the neuropeptide changes were already evident in the 31-50 age group. Since BE has been shown to participate in the modulation of the immune system, the age-related modifications of PBMC BE could play a role in the immunodepression observed during aging.

Chronic intrathecal cannulation affects hypothalamic opioids depending on the technique employed

Previous studies have shown that chronic intrathecal cannulation can interfere with the homeostasis of central opioid peptides. These results show that beta-endorphin and Met-enkephalin concentrations did not change in the hypothalamus of rats bearing a chronic cannula inserted between C8-T1 up to L3 and fixed to the processes transversus T1. These results suggest that chronically cannulated rats can be considered as normal when studying hypothalamic beta-endorphin or Met-enkephalin concentrations, and used in physiological studies, depending on the technique employed.

High amounts of beta-endorphin in peripheral blood mononuclear cells from HANE patients

We measured peripheral blood mononuclear cells (PBMC) beta-endorphin (BE) in patients suffering from hereditary angioneurotic edema (HANE), a disease attributed to C1-esterase inhibitor (C1INH) deficiency inherited as an autosomal dominant trait. Two orders of considerations prompted us to undertake the study reported herein: the presence of elevated plasma BE concentrations in HANE and the demonstration of BE-immunoreactivity in human unstimulated peripheral blood leukocytes obtained from healthy volunteers. Our results show that patients suffering from HANE have a very high BE presence in uncultured, unstimulated PBMC and in unstimulated PBMC cultured for 48 h. At this time high BE concentrations are detected in the culture supernatants. These observations suggest that in HANE patients the same factor(s) involved in causing increased secretion and release of BE from the pituitary (and, in turn, increased plasma BE levels) can play a relevant role also in the determination of high BE presence in PBMC and BE release from the cells.

Corticotropin releasing hormone, interleukin-1 alpha, and tumor necrosis factor-alpha share characteristics of stress mediators

Interleukin-1 alpha and tumor necrosis factor-alpha induce an increase in pain thresholds in the rat. We now show that also the corticotropin releasing hormone induces an analgesic effect that, similarly to what is observed with the two cytokines, is not reversible by naloxone. Moreover, we also show that after the administration of interleukin-1 alpha, tumor necrosis factor-alpha, and corticotropin releasing hormone, naloxone becomes analgesic itself. A similar observation was also made in the human and the experimental animal after exposure to stressful conditions. The results obtained suggest that the two cytokines share with corticotropin releasing hormone some characteristics of stress mediators.

Pharmacological modulation of neuropeptides in peripheral mononuclear cells

The concentrations of beta-endorphin and cholecystokinin were measured in fresh resting peripheral mononuclear cells obtained from rats and human subjects in basal conditions and after different pharmacological treatments. Both in the human and the rat, beta-endorphin concentrations in mononuclear cells, increased after treatment with serotoninergic agonists, decreased after dopaminergic or GABAergic drugs, while the respective antagonists exerted the opposite effect. In vitro, serotoninergic and GABAergic compounds confirmed their roles in the modulation of beta-endorphin in mononuclear cells. Cholecystokinin was never affected by the pharmacological treatments.

Inhibin and activin modulate human monocyte chemotaxis and human lymphocyte interferon-gamma production

Inhibin and activin are referred to as gonadal glycoprotein hormones whose function is the control of FSH release from the pituitary gland. However, several observations indicate that inhibin and activin are produced in various organs and serve multiple functions. Because bone marrow and spleen produce inhibin and activin, our aim was to evaluate their possible effect on cell-mediated immune function. For this reason we studied 1) monocyte chemotaxis, 2) lymphocyte interferon-gamma production, 3) phytohemagglutinin-induced lymphocyte proliferation, and 4) nonmajor histocompatibility complex-restricted and lymphokine-activated lymphocyte cytotoxicity. All studies were performed on human peripheral blood cells in the absence or presence of various doses of inhibin, activin, or inhibin plus activin. A significant dose-related increase in monocyte chemotaxis was induced by inhibin. Activin increased the migrational activity of monocytes, but via random, not directed, migration. Inhibin significantly decreased interferon-gamma production, and its effect was reversed by activin. Inhibin and/or activin had no significant effect on either phytohemagglutinin-induced lymphocyte proliferation or lymphocyte cytotoxic capability. The present demonstration that inhibin and activin may affect some immune parameters suggests a possible involvement of these hormones in regulating cell-mediated immune function.

Visualization of cholecystokinin receptors on a subset of human monocytes and in rat spleen

Direct radioreceptor binding experiments and Scatchard analysis reveal CCK receptors on elutriator purified human peripheral blood monocytes, but not on purified human T cells. The monocyte receptors have a single class of high (0.1 nM) affinity binding sites. A structure-function analysis of monocyte binding by different CCK analogs correlates well with previously demonstrated chemotactic responses in monocytes and receptors in brain tissue. Biochemical cross-linking indicates that the monocyte CCK recognition molecule is comparable in molecular size to that in brain membranes. Utilizing a novel fluoresceinated Texas Red-CCK conjugate we have visualized that up to 20% of human peripheral monocytes bear receptors for CCK. A discrete and anatomically significant distribution of CCK receptors in rat spleen is shown by film autoradiography of tissue sections. A more detailed microscopic analysis identifies a dendritic population of monocyte-derived cells within the periarteriolar lymphocyte sheath (PALS) of the white pulp as the CCK receptor-bearing cell in spleen. The anatomical localization of receptor-bearing cells within the PALS region suggests a role for CCK in the antigen processing and sensitization phases of the immune response via regulatory effects of this peptide on a specific, local macrophage-related cell population.

Traditional acupuncture increases the content of beta-endorphin in immune cells and influences mitogen induced proliferation

We measured beta-endorphin concentrations in peripheral blood mononuclear cells and mitogen-induced T-lymphocyte proliferation in patient who underwent treatment with traditional acupuncture. Traditional acupuncture increased both the concentrations of the opioid in the immune cells and lymphocyte proliferation. Our data are consistent with the hypothesis that traditional acupuncture modulates immune responses in man.

Studies on the effects of antidepressant drugs on the antinociceptive action of morphine and on plasma morphine in rat and man

In the rat we studied the effect of 3 tricyclic antidepressants: chlorimipramine, amitriptyline and nortriptyline, and the atypical antidepressant trazodone on pain thresholds when administered alone or together with morphine. Moreover, we evaluated the effect of the antidepressants on free morphine plasma concentrations both in the rat and in man. We observed that chlorimipramine and amitriptyline, two tricyclic antidepressants active on the serotoninergic system, induce analgesia and potentiate morphine analgesia in a dose-related fashion. The noradrenergic tricyclic nortriptyline and trazodone did not elicit analgesia and inconsistently affected morphine analgesia. In the rat, all drugs tested increased plasma concentrations of morphine with the exception of amitriptyline. In man, only chlorimipramine and amitriptyline increased the plasma concentration of the free opiate.

Effect of psychoactive drugs on lymphocyte neuropeptides

The concentrations of beta-endorphin and cholecystokinin were measured in lymphocytes obtained from young or old rats and from humans at different ages. Both in rats and humans, beta-endorphin and cholecystokinin increase with age; also in vitro, after 48-h culturing, the concentrations of beta-endorphin and cholecystokinin in lymphocytes obtained from humans of different ages changed with the same pattern observed in ex vivo experiments. In the human, beta-endorphin in lymphocytes shows a circadian rhythm that shifts approximately 6 h when compared to plasma ACTH and cortisol rhythm. The HPLC analysis of the molecular forms of beta-endorphin in lymphocytes revealed the presence of N-acetyl-beta-endorphin, with a ratio of beta-endorphin to N-acetyl-beta-endorphin ranging from 1 to 2. The concentrations of beta-endorphin and cholecystokinin were also measured in lymphocytes obtained from rats and human subjects undergoing different pharmacological treatments. In rat, the serotonin receptor antagonist metergoline decreased basal concentrations of the opioid peptide and blocked the increase of beta-endorphin concentrations induced by the serotonin precursor 5-hydroxytryptophan and the tricyclic antidepressant chlorimipramine. Also in the human, the antidepressant drug chlorimipramine increased lymphocyte beta-endorphin concentrations. In contrast to what was observed for beta-endorphin, cholecystokinin concentrations were not affected by the modulation of the serotoninergic system. Chronic treatment of rats with the dopamine receptor antagonist haloperidol induced an increase of beta-endorphin concentrations in lymphocytes that was reversed by the concomitant treatment with the dopamine receptor agonist bromocriptine, which when given alone decreased the basal concentrations of the peptide. In the human, haloperidol increased concentrations of beta-endorphin after both 24 h and chronic treatment, while cholecystokinin was never affected. Finally, beta-endorphin, but not cholecystokinin, increases both in rat and human lymphocytes after treatment with the GABA agonist sodium valproate.

Cellular sources and effects of tumor necrosis factor-alpha on pituitary cells and in the central nervous system

Cytokine-mediated communication between the immune system and the nervous system has been shown in the past few years. The precise cellular sources of these molecules in the brain is still a controversial issue. We have thus immortalized primary cell cultures from mouse embryonic brains to analyze cloned cells involved in cytokine production. The cell clones obtained were identified as microglial cells and shown to produce several monokines. Among these, TNF alpha was detected by molecular analysis and cytotoxicity assays and shown to be expressed by microglial cells, after activation with LPS. Surprisingly, the TNF alpha-mediated cytotoxic activity, which was neutralized by specific antisera, was not detected in the cell supernatants but was mediated through cell-to-cell contact. Using antibodies to TNF alpha in FACS analysis, specific cell membrane staining on live microglial cells was shown. The results suggest that in the brain the form of TNF alpha detectable by standard procedures is the cell bound form and not the most common form, secreted TNF alpha. In addition, the effects of recombinant TNF alpha in vitro and in vivo were evaluated. In vitro, rTNF alpha stimulated beta-endorphin, GH, and PRL release from cultured cells prepared from rat anterior pituitary glands. In vivo, the administration of rTNF alpha to rats was able to modify analgesic responses. The concomitant administration of naloxone, an opiate receptor antagonist, or monoclonal anti-IL-1 antibody decreased the analgesic effects induced by rTNF alpha. This indicates that the analgesic effect might not be mediated directly by rTNF alpha but by other mediators, whose action is under the control of TNF alpha.

Benzodiazepines and their antagonists interfere with opioid-dependent stress-induced analgesia

Timing or intensity of shocks significantly modify the characteristics of the analgesia induced by footshock, and conditioning to footshock induces analgesia, independently from the time and shock parameters used for conditioning. However, whatever the parameters of shock, and the presence of conditioning or not, the stress has to be inescapable in order to produce an increase in pain thresholds. This observation suggests that anxiety plays a major role in the development of stress-induced analgesia. In order to test this hypothesis we investigated the effects of the benzodiazepine agonists diazepam and clonazepam, the antagonists RO 15-1788, CGS 8216, CGS 9896, and the inverse agonists FG 7142 and FG 7041 on the development and maintenance of stress-induced analgesia. Benzodiazepine receptor agonists decreased the analgesic effect of inescapable footshock, benzodiazepine receptor antagonists increased the footshock induced analgesia, whereas inverse agonists did not modify the analgesia induced by the shock. All the benzodiazepine receptor ligands blocked the antagonism of the footshock analgesia induced by naloxone.

Asymmetrical distribution of beta-endorphin in cerebral hemispheres of suicides: preliminary data

The assessment of beta-endorphin levels in several symmetrical brain regions of seven suicides and seven sudden death controls reveals a decreased concentration in the left temporal cortex, the left frontal cortex, and the left caudate nucleus of suicides compared to controls. Moreover, the comparisons of beta-endorphin concentrations in the symmetrical brain regions reveals an asymmetrical concentration in suicides (left less than right) in frontal cortex and caudate nucleus. These data confirm previous reports of abnormalities of neurochemical pathways in the brains of suicides and suggest that suicidal behavior might be related to the lateralized mechanisms of mood control.

Human monocyte chemotactic activity of calcitonin and somatostatin related peptides: modulation by chronic peptide treatment

Neuropeptides are common mediators of the nervous and the immune systems. We investigated whether two families of peptides, calcitonin (CT) and somatostatin, posses human monocyte chemotactic activity. CT-related peptides induce a significant chemotactic response, and the potency order is: salmon CT greater than human CT greater than CT much greater than carbo-CT; CT gene-related peptide is completely inactive. This rank potency order differs from that in other systems (e.g. bone and nervous system). The chemotactic response of monocytes obtained from patients chronically treated with either salmon CT or carbo-CT is impaired, thus suggesting a phenomenon of down-regulation of a common receptor on monocytes. While somatostatin-(1-14) is completely inactive on monocyte chemotaxis, the synthetic analog SMS 201995 is extremely potent. Also, in this case the prolonged treatment of patients with SMS 201995 leads to an impaired chemotactic response.

Analysis of the beta-endorphin structure-related activity on human monocyte chemotaxis: importance of the N- and C-terminal

We evaluated the chemotactic activity of beta-endorphin and beta-endorphin-related peptides on human monocytes. We tested beta-endorphin(1-31) and fragments (1-16), (1-17), (1-27) in which the N-terminal of the opioid is preserved, N-acetyl-beta-endorphin(1-31) and fragments (6-31) and (28-31) in which the C-terminal is preserved, and fragment (2-17) that lacks both the N- and C-terminal. The fragments in which the N- and C-terminal were preserved [with the exception of fragment (28-31)] showed a chemotactic effect, while the lack of both terminals deprived the peptides of any activity. Moreover, only the N-terminal-mediated effects were naloxone reversible, while the C-terminal effects were not. These results indicate that while the intact N-terminal is necessary for opioid like effects, both N- and C-terminal can mediate effects on the immune system, thus offering evidence for a nonopioid receptor-mediated effect of opioid peptides on the immune system.