[Summary: Scientific evaluation of EMDR psychotherapy]. / Évaluation scientifique de la psychothérapie EMDR pour le traitement des traumatismes psychiques.

OBJECTIVE: The evaluation of psychotherapy methods is made difficult by their practical and theoretical diversities as well as the increasing number of available therapies. Evaluation based on scientific criteria in randomized control trials is providing the highest level of proof and recognition by Health Agencies. A recently described integrative psychotherapy, eye movement desensitization and reprocessing (EMDR), developed by F. Shapiro since 1989, has been confronted with the validation procedure used in pharmacological treatment. It was of interest to review the scientific validation steps carried out for this EMDR psychotherapy and for its mechanisms of action. AIM OF THE REVIEW: The practical and methodological protocol of the EMDR psychotherapy for trauma integration is reviewed as well as clinical results and mechanisms. RESULTS: This EMDR therapy, focused on the resolutions of traumas, was started by treating patients with post-traumatic stress disorders (PTSD). The integrative EMDR protocol obtained the highest level of efficiency, for PTSD treatment, twenty years after its first publication. The efficiency of the protocol is now under study and scientific evaluation for troubles in which the trauma experiences are triggers or factors of maintenance of the troubles: anxiety, depression, phobia, sexual troubles, schizophrenia, etc. CONCLUSION: This new integrative psychotherapy follows the pathways and the timing observed for the evaluation and the validation of other therapies.

[Magneto-encephalographic (MEG) brain recordings during traumatic memory recall in women with post-traumatic stress disorder: A pilot study]. / Enregistrement magnéto-encéphalographique (MEG) de réminiscences du trauma chez des femmes souffrant de stress post-traumatique : une étude pilote.

AIM OF THE STUDY: The experiment studied the effects of a short duration exposure to traumatic memories using magneto-encephalography (MEG). PATIENTS: Nine right-handed DSM-4 PTSD patients were recruited from a unit for anxiety disorders and an organisation supporting victims of violence. In order to have a homogeneous sample, we included only women who suffered from civilian PTSD. Exclusion criteria were co-morbid major medical illness, metallic dental prostheses that would interfere in the magnetic measurement, and current drug treatment. All participants were free from neurological disease and had normal hearing. They signed a written informed consent form. An ethics committee accepted the study. METHOD: A tape-recorded voice administered a script-driven imagery. The patients had to imagine, successively, a neutral image, a traumatic memory and rest, while MEG measured brain activities across delta, theta, alpha and beta bands. Each condition lasted three minutes. Heart rate (HR), anxiety and the vividness of mental images were recorded at the end of each phase. MEG power analysis was carried out with Statistical Parametric Mapping (SPM) 8. The signals were averaged for each of the three conditions of threeminutes duration. The dependent variable was a subtracted value: (trauma - rest) - (neutral - rest). The significance threshold was set at P<0.01. RESULTS: Anxiety and HR significantly increased during the trauma condition and returned to the neutral level during rest. The vividness of the mental imagery remained stable across the three conditions. The left-brain demonstrated a statistically significant power decrease in the secondary visual cortex (BA 18-19) in the delta band, the insula (BA13) in the beta band, the insula (BA13), premotor cortex (BA 6), Broca area (BA 44), and BA 43, in the alpha band. DISCUSSION: The symptom provocation protocol was successful in eliciting subjective anxiety and HR response in relation to traumatic memories. Our MEG results are in keeping with previous neuro-imagery studies showing decreased activities in the insula and Broca area during PTSD symptom provocation. However, we did not replicate the activation in the amygdala and the cingulate and prefrontal cortex found in some studies. Moreover, the within-group design, the small sample, and the inclusion of only female patients with milder dissociative symptoms limit our conclusions. The MEG protocol we used may also explain some partial discrepancies with previous MEG studies. However, our aim was to provoke a specific autobiographic recall of a traumatic event unfolding several sequential mental images along three minutes as in exposure therapy for PTSD. CONCLUSION: Despite its limitations, this pilot study is the first to provide MEG data during trauma recall. It suggests that recalling a specific traumatic event along three minutes results in hypo-activations of the brain regions regulating language and emotions. This paves the way to recording whole sessions of specific therapies for PTSD, with MEG using the millisecond resolution. MEG might be of interest to study the suppression of traumatic memories and their activation and habituation through prolonged graduated exposure in imagination across several sessions. MEG could also be used to study the effects of medication on PTSD symptoms. A controlled replication in a larger sample including male and female patients with various traumatic experiences is needed.

Distribution, cellular localization and functional role of CCR2 chemokine receptors in adult rat brain.

Recent studies demonstrated that the chemokine monocyte chemoattractant protein-1 (MCP-1)/CCL2 and its receptor, CCR2, play important roles in various brain diseases. In this study, using quantitative autoradiography, we studied the pharmacological properties of [125l]MCP-1/CCL2 binding in rat brain and we clearly showed the distribution of CCR2 receptors in cerebral cortex, nucleus accumbens, striatum, amygdala, thalamus, hypothalamus, hippocampus, substantia nigra, mammillary bodies and raphe nuclei. Moreover, using double fluorescent immunohistochemistry, we showed that CCR2 receptors were constitutively expressed on neurons and astrocytes. Using RT-PCR methods, we demonstrated that CCR2 mRNA is present in various brain areas described above. Four hours after an acute intraperitoneal lipopolysaccharide injection, we showed that MCP-1/CCL2 binding was up-regulated in several brain structures; this effect took place on both CCR2B labelled neurons and astrocytes and to a lesser extent on activated microglia. To explore neurobiological function of CCR2, actimetric study was carried out. After intracerebroventricular injections of MCP-1/CCL2, we showed that motor activity was markedly decreased. Our results provide the first evidence for constitutive CCR2 receptor expression with precise neuroanatomical and cellular localizations in the brain, and its regulation during an inflammatory process, suggesting that MCP-1/CCL2 and CCR2 play important physiological and pathophysiological role(s) in the CNS.

Characterization and visualization of [125I] stromal cell-derived factor-1alpha binding to CXCR4 receptors in rat brain and human neuroblastoma cells.

Stromal cell-Derived Factor-1 (SDF-1alpha), binds to the seven-transmembrane G protein-coupled CXCR4 receptor and modulates cell migration, differentiation, and proliferation. CXCR4 has been reported to be expressed in various tissues including brain. Moreover, CXCR4 has recently been shown to be one of the coreceptors for HIV-1 infection which could be implicated in HIV encephalitis. In the present study, the binding properties and autoradiographic distribution of [125I]SDF-1alpha binding to CXCR4 were characterized in the adult rat brain. SDF-1alpha binding and CXCR4 coupling system were also studied in human neuroblastoma cell line SK-N-SH. The binding of [125I]SDF-1alpha on rat brain sections was specific, time-dependent and reversible. The highest densities of CXCR4 were detected in the choroid plexus of the lateral and the dorsal third ventricle. Lower densities of [125I]SDF-1alpha binding sites were observed in various brain regions including cerebral cortex, anterior olfactory nuclei, hippocampal formation, thalamic nuclei, blood vessels and pituitary gland. In the choroid plexus, the IC(50) and K(d) of [125I]SDF-1alpha binding were respectively 0.6 nM and 0. 36 nM. Similar IC(50) values were obtained in other brain structures. A CXCR4 antagonist, bicyclam, competed with SDF-1alpha binding (30% inhibition at 10(-6) M). In SK-N-SH cells, [125I]SDF-1alpha bound to CXCR4 with a K(d) of 5.0 nM and a maximal binding capacity of 460 fmol/mg of protein. SDF-1alpha induced a rapid and transient intracellular calcium increase in SK-N-SH cells. These findings suggest that CXCR4 is highly expressed in some brain structures and have a regulatory role in the nervous system. The significance of this expression in the brain parenchyma and more specifically in the choroid plexus remains to be clarified in the normal as well as in the infected brain.

Increased sensitivity of prediabetic nonobese diabetic mouse to the behavioral effects of IL-1.

The nonobese diabetic (NOD) mouse is a model of spontaneous insulin-dependent diabetes mellitus (IDDM) or type I diabetes. In humans, and in animal models of IDDM, the progression of the disease is modulated by various environmental factors, particularly infectious agents. Interleukin-1 (IL-1) plays a pivotal role in the development of IDDM, and modulation of its synthesis may be a mechanism by which environmental modulation of disease progression occurs. Since various alterations at the level of the gene, number, and sensitivity of IL-1 receptors have been described in different animal models of autoimmune disease, we investigated, in the prediabetic NOD mouse, the presence of IL-1 receptors and their functional behavioral characteristics. Here we present evidence that prediabetic NOD mice exhibit a normal distribution and density of functional brain IL-1 receptors, but are more sensitive to the behavioral effects of IL-1 than the control ICR strain.

Expression of interleukin-1 genes and interleukin-1 receptors in the mouse brain after hippocampal injury.

In order to evaluate the role of IL-1 production in post-traumatic brain, transcripts for IL-1 (alpha, beta, RA) have been quantified following RT-PCR, in hippocampus and cortex after injury of either hippocampus (Hip) or striatum (Stri). Moreover, 125I IL-1alpha binding sites have been directly quantified using binding experiments on brain sections and quantitative autoradiography. Under basal conditions, levels of PCR products were very low. On day 1, IL-1RA transcripts only were strongly increased in the hippocampus after Hip-lesions and in cortex after Stri lesion. Transcripts were back to control values on day 7 post-lesion. IL-1 receptor densities in the hippocampus (dentate gyrus) were decreased at day 1 around the site of the lesion (but not on the contralateral side) and were back to controls on day 7 indicating a transient and local IL-1 production in the surroundings of the lesion. No changes were found following Stri lesion. This study provides further evidence of the role of the IL-1 molecules family, notably IL-1RA, in the brain reaction to trauma.

Interleukin-1 receptor defect in autoimmune NZB mouse brain.

Interleukin-1 receptors (IL-1R type I and II) have been characterized in murine nervous structures (hippocampus and frontal cortex), in vascular structures (vessels, choroid plexus), and in the anterior pituitary. Because interleukin-1 (IL-1), injected or induced in the brain, is a powerful regulator of the stress axis and immune functions, it was of interest to investigate IL-1Rs and IL-1 in autoimmune mice. In control mice, bacterial lipopolysaccharide (LPS), administered i.p. or i.c.v., induces a sharp decrease in available brain IL-1 receptors, in spite of a moderate increase in mRNAs for both receptor types. This is concomitant with an increase in IL-1 alpha, beta, and ra mRNA. Ligand production clearly overcomes receptor turnover. In autoimmune mice (NZB and NZB/NZW F1), a strong defect in IL-1R (type I) is demonstrated in the dentate gyrus. This tissue-specific defect cannot be explained by increased occupancy by endogeneous ligands as for LPS-treated mice. The transmission of the defect is Mendelian and suggests the involvement of a single gene. However patterns of IL-1R mRNAs (evaluated by RT-PCR) are similar in NZB and in controls, suggesting a translational or post-translational abnormality. The contribution of this genetic disorder in the development of autoimmunity remains to be clarified. Because the brain IL-1 system sends inhibitory signals towards immune functions, this lack of functional IL-1 binding sites might participate in the disregulations observed in NZB autoimmune mice.

Interleukin-1 receptor deficiency in the hippocampal formation of (NZB x NZW)F2 mice: genetic and molecular studies relating to autoimmunity.

Interleukin-1 receptor (IL-1R) deficiency has been previously described in the dentate gyrus of autoimmune NZB and (NZB x NZW) F1 (or BWF1) mice. In this study, the genetic and molecular characterization of this defect were investigated in BWF2 mice in relation to anti-DNA antibody production and microsatellite D1Nds4 (near the IL1r1 gene) polymorphism. IL-1R density was quantified in the brain, spleen and pancreas, using in vitro quantitative autoradiography with recombinant human [125I]-IL-1alpha as the ligand. This study of the dentate gyrus of F2 mice revealed three phenotypes: NZW-like, NZB-like and F1-like, which occurred in a ratio of 1:1:2, with IL-1R densities of 100%, 17% and 59%, respectively as compared to control NZW mice (100%). In contrast, IL-1R densities observed in the choroid plexus and peripheral organs were similar. Moreover a high production of IgG2a anti-DNA antibodies was observed in F2 mice, as in their parents, particularly those with the NZB-like phenotype. Microsatellite mapping of D1Nds4 revealed polymorphism in both parents and BWF2 mice in relation to the level of IL-1R density in the dentate gyrus. In spite of the acute defect in IL-1 binding in the dentate gyrus of NZB mice, molecular analysis of IL-1R mRNA (type I, II and accessory protein) showed similar amounts of mRNA, measured following RT-PCR amplification, in the hippocampal formation of both NZB and control C3H/He mice. In conclusion, the transmission of the IL-1R defect in the dentate gyrus of NZB mice is monofactorial and the defect appears to be at the post-transcriptional level of IL-1R synthesis. The lack of IL-1R in the dentate gyrus seems to correlate with some autoimmune characteristics. Correlation of D1Nds4 polymorphism with the level of IL-1R density suggests that it could be a predisposing gene to disease or a marker for other closely linked predisposing genes.

Type I and type II interleukin-1 receptor expression in rat, mouse, and human testes.

Despite clear indications of interleukin-1 (IL-1) action on Sertoli and germ cells, previous studies failed to detect IL-1 receptors (IL-1R) within the seminiferous tubules. Here, we investigated the existence of the type I signaling receptor (IL-1RI) and the type II decoy receptor (IL-1RII) mRNAs within the testis. Polymerase chain reaction analysis showed the presence of both receptor mRNAs in isolated rat, mouse, and human somatic testicular cells (macrophages, Leydig, Sertoli, and peritubular cells). While also present in rat and mouse isolated pachytene spermatocytes and early spermatids, these receptor mRNAs were not found in human germ cells. The distribution of both IL-1R mRNAs was then examined in adult rat and mouse testis using light and electron microscopic in situ hybridization. No IL-1RI signal was detected in rat testis. In mouse testis, we did not find any signal for IL-1RII. In contrast, IL-1RI mRNA was detected in a wide variety of mouse testicular cells. Strong expression was observed in the rete testis area and high expression was seen over the epithelium of the epididymal duct and in interstitial cells, while lower labeling was detected in peritubular and Sertoli cells and in all germ cell types from spermatogonia to early spermatids; no signal was seen in late spermatids. That the IL-IR was also strongly expressed in the interstitium, the rete testis and efferent duct areas, and the epididymis was established using an autoradiography technique. Overall, our study strongly supports the hypothesis that IL-1 is a regulator of testicular function of prime importance.

Analysis of brain mRNA by reverse transcription-polymerase chain reaction and hybridization with digoxigenin-labeled DNA probe.

The interleukin-1 family of polypeptides (IL-1 alpha, IL-1 beta and IL-1 receptor antagonist (RA)) induces various centrally mediated host defense responses to infectious pathogens. Considerable interest has focussed on IL-1 as a mediator in disease and in the production of systemic acute phase responses. We have recently studied the effects of a peripheral stimulation by intraperitoneal (i.p.) administration of lipopolysaccharide (LPS) on the mRNAs expressions of IL-1 (alpha, beta, RA) and their receptors (IL-1 receptor type I and type II (IL-1R1, IL-1R2)) in the central nervous system (CNS). The levels of these expressions being very low in the CNS, the reverse transcription-polymerase chain reaction (RT-PCR) techniques are required for these studies. RT-PCR is a developed method of identifying mRNAs in very small amount of nucleic acid. We have previously developed a method to choose specific PCR primers. The detection of specific PCR products is extremely important. Since amplifications with these specific PCR primers can be achieved under the same conditions (buffers and temperatures) reliable results can be obtained. Characterization of a PCR product requires the use of a specific DNA probe that hybridizes to the region of interest. In addition to providing specificity of detection, the use of labeled DNA probes provides increased sensitivity over ethidium bromide staining. We have previously described a method of synthesis of non-radioactive probe labeled with digoxigenin by nested PCR. Moreover the major advantage to the use of non-radioactive label is that it does not have a short half-life and can last for weeks or even months. A quantification of the PCR products can be obtained using a method based on the analysis of photographic negatives of agarose gels.

Disturbed immunoendocrine communication via the hypothalamo-pituitary-adrenal axis in murine lupus.

Immune reactions and mitogen stimulation of mammals and chickens lead to an increase of glucocorticoid (GC) plasma levels concomitant with the immune response. Interleukin (IL) 1, one of the most important glucocorticoid increasing factors produced by cells of the immune system, acts via the hypothalamo-pituitary-adrenal (HPA) axis. This pattern of immunoendocrine feedback communication is altered in autoimmune disease (AID) and represents a possible site of action for GC therapy. In the present study we investigated the role and possible underlying mechanisms of a disturbed immunoendocrine communication via the HPA axis in murine lupus. We analyzed the response to recombinant human (rhu) IL-1alpha in AID-prone mice [NZB, NZW, (NZB/NZW)F1, MRL/MP-lpr] in comparison to nonautoimmune, normal control mice (Swiss, C3H/HeJ, MRL/MP-+/+) at different levels of the HPA axis. To this end, we quantified the plasma levels of ACTH, corticosterone, and corticosterone-binding globulin (CBG) and determined various pathology parameters for autoimmunity. AID-prone mice produced nearly the same levels of plasma corticosterone after injection of rhu IL-1alpha as normal mice, but had baseline corticosterone levels consistently higher, thus resulting in significantly lower corticosterone increasing ratios. ACTH levels increased after rhu IL-1alpha injection, but there was no clearcut difference in the increasing ratios of AID-prone and normal strains. CBG levels showed no difference. As expected, there was a correlation of pathology parameters for autoimmunity and the altered immunomodulatory response to rhu IL-1alpha per group. On an individual basis, there was no such correlation. In conclusion, our results confirm the existence of a disturbed immunoendocrine communication in AID-prone mice. This disturbance clearly differs from individual to individual and also among different types of AID.

Radioimagers as an alternative to film autoradiography for in situ quantitative analysis of 125I-ligand receptor binding and pharmacological studies.

Three radioimagers, the mu-imager, the beta-imager and the phosphorimager, were tested as alternatives to quantitative autoradiography on film, for receptor imaging and pharmacological in situ quantitative analysis. Two iodinated ligands 125I-interleukin-1 alpha and 125I-gonadotropin releasing hormone agonist were used for receptor characterization in mouse brain and pituitary sections. Due to the high number of the agonist receptors in rat pituitary gland, this tissue was used to compare measurements obtained from digital autoradiograms with classical gamma detector determination. This permits the evaluation of radioimager efficiency and absolute quantification. Radioimagers represent an improvement in terms of time of image acquisition. All the radioimagers are more sensitive than film for the detection of low levels of radioactivity. The spatial resolution provided by the mu-imager compares favourably with that obtained on film autoradiograms while digital autoradiograms from the phosphorimager and beta-imager did not show precise definition under our experimental conditions. Superimposition of histological structures from the stained sections with radiolabelled areas in the autoradiograms remains, at this time, the unique advantage of film. In conclusion, radioimagers represent an alternative to autoradiography on film or emulsion for in situ quantitative studies on tissue sections. They combine precise imaging for in situ binding studies with easy and direct access to counts in cpm. The improvement in radioimaging technology has, therefore, brought in situ analysis of iodinated ligand binding to the level of accuracy that is obtained with classical detectors of radioactivity.

Interleukin-1 receptor accessory protein transcripts in the brain and spleen: kinetics after peripheral administration of bacterial lipopolysaccharide in mice.

Receptors for IL-1, type I (IL-1R1) and type II (IL-1R2), have been characterized by pharmacological and molecular techniques in the mouse brain. High densities are mainly found in the cortex, dentate gyrus and choroid plexus. It was therefore of interest to investigate the expression of mRNA IL-1 receptor accessory protein (IL-1R AcP), which is a part of the IL-1 receptor complex and has been shown to interact specifically with IL-1R1. IL-1R AcP transcripts were detected under basal conditions following RT-PCR amplification in the mouse brain, as well as in the pituitary, spleen, adrenal and liver. IL-1R AcP transcripts were found in higher amounts than IL-1R1 transcripts in all tissues except the spleen, where their expression was minor. Following bacterial lipopolysaccharide (LPS) stimulation (3-48 h), IL-1R AcP transcripts were not changed in the brain, while IL-1R1 transcripts were increased for 3-6 h. In the spleen, a slight increase in IL-1R AcP and IL-1R1 was observed during the first hours following LPS stimulation. In conclusion, IL-1R AcP mRNA is expressed in the brain and in other tissues where IL-1R1 transcripts are found. However, the regulation of its expression is distinct from IL-1R1. The high level of expression and the lack of regulation of IL-1R AcP transcripts in the brain under inflammatory conditions suggest that the protein might be constitutively expressed in excess.

Induction of immunoreactive interleukin-1 beta and tumor necrosis factor-alpha in the brains of rabies virus infected rats.

Interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF alpha) are important cytokines in the development of brain inflammation during pathological process. During rabies virus infection, the level of these proinflammatory cytokines are enhanced in the brain. In the present study we determined the cellular localization of these two cytokines by immunocytochemistry in brains of rats infected with rabies virus, at different time-intervals of the disease (day 1, 3, 4, 5 and at final stage day 6 post-infection (p.i.)). Cellular identification of IL-1 beta (irIL-1 beta) and TNF alpha (irTNF alpha) immunopositive cells was studied using a polyclonal antibody against these cytokines and against glial fibrillary acidic protein (GFAP) to detect astrocytes and GSA-I-B4 isolectin to detect microglial cells and/or infiltrating macrophages. In brains of control and early infected rats, irIL-1 beta was only detected in fibers located in the hypothalamus, supraoptic and tractus optic nuclei and infundibular nucleus. From day 4 onwards until day 6 p.i., enhanced irIL-1 beta was found and identified either in activated ameboid and/or infiltrated macrophages (amygdala, thalamus, internal capsula, subtantia nigra, septal nuclei and around blood vessels), or in activated ramified cells (hypothalamus and periventricular nucleus, piriformis and cingulate cortex, hippocampus). IrTNF alpha was observed in the brains of rats at a final stage of disease (day 5 and 6 p.i.): in the hypothalamus, the amygdala, the internal capsula, the thalamus, the septal nuclei, the hippocampus, the habenular nuclei and around the blood vessels. Ir-TNF alpha was detected in round cells identified as ameboid microglia and/or infiltrated macrophages. A marked activation of microglial and astroglial cells was observed mainly in the hypothalamus, the thalamus and hippocampus and around the blood vessels, at day 4 p.i. and later, revealing a high central inflammatory reaction in brains of rabies virus infected rats. These results showed that IL-1 beta and TNF alpha are produced in the brain both by local microglial cells and infiltrating macrophages during rabies infection. Thus, these cytokines may play an important role in coordinating the dramatic inflammatory response associated with the rabies-encephalopathy as well as in the neural modification and alteration of brain functions.

Interleukin-1 receptors type I and type II in the mouse brain: kinetics of mRNA expressions after peripheral administration of bacterial lipopolysaccharide.

The expression of transcripts for Interleukin-1 (IL-1) type I and type II receptors (IL-1R1, IL-1R2) was investigated in the mouse brain and spleen using reverse transcription-polymerase chain reaction techniques under basal conditions and following injection of endotoxin (LPS, i.p., 4 mg/kg). Under basal conditions, mRNAs for both receptor types were found in various parts of the brain, in pituitary as well as in spleen. Following LPS stimulation, mRNA expressions were increased in all studied tissues. IL-1R1 mRNAs were predominant in the brain and pituitary while, IL-1R2 mRNAs were more abundant in the spleen. The maximal quantity of transcripts (IL-1R1, IL-1R2) was obtained 6 h after LPS injection in all studied tissues. The decrease to basal level was observed within 48 h in the brain. In the spleen, IL-1R1 mRNAs remained elevated 48 h after LPS while IL-1R2 mRNAs had already reached basal level. These results indicate a LPS-induced stimulation of IL-1 receptors mRNAs in the brain and a differential expression of IL-1R1 and IL-1R2 transcripts in brain and immune tissues.

Interleukin-1 effect on glycemia in the non-obese diabetic mouse at the pre-diabetic stage.

Cytokines, particularly interleukin 1 (IL-1) and tumor necrosis factor, are known to induce hypoglycemia in normal rodents or different experimental models of type II diabetes. We investigated, at the pre-diabetic stage, the effect of short-term administration of murine recombinant interleukin-1 alpha (mrIL-1 alpha) on the levels of glucose, insulin and corticosterone in the non-obese diabetic (NOD) mouse, a spontaneous model of type I diabetes. Two-month-old, pre-diabetic NOD mice of both sexes were insensitive to mrIL-1 alpha (12.5 and 50 micrograms/kg) 2 h after administration, the time at which the maximal decrease (around 50%) was observed in the C57BL/6 mouse strain. Kinetic studies however showed that mrIL-1 alpha lowered glycemia in both sexes of NOD mice, but the effect was limited and delayed. In the NOD and C57BL/6 strains, mrIL-1 alpha had no influence on insulin levels in females, but significantly increased them in males (P < 0.0001). Castration of NOD males abrogated the stimulatory effect of mrIL-1 alpha on insulin secretion. Corticosterone secretion was stimulated by mrIL-1 alpha in both sexes of NOD and C57BL/6 mice, and this effect was faster and greater in NOD females than in C57BL/6 females. The incomplete hypoglycemic response to mrIL-1 alpha in females may be attributed to the anti-insulin effect of glucocorticoids, an effect which can be demonstrated when mrIL-1 alpha is administered to adrenalectomized animals or when mrIL-1 alpha is administered together with the glucocorticoid antagonist RU38486. In NOD males, in contrast, glucocorticoids did not play a major role in the limited hypoglycemic response to mrIL-1 alpha, since RU38486 and adrenalectomy were not able to unmask a hypoglycemic effect. Moreover, NOD mice of both sexes were less sensitive than C57BL/6 mice to the hypoglycemic effect of insulin (2.5 U/kg), which suggests some degree of insulin-resistance in NOD mice. With regard to the effect of IL-1 on NOD mouse glycemia, therefore, these results suggest that glucocorticoids and/or androgens, according to the animal's sex, may induce a state of insulin-resistance.

Alteration of interleukin-1 alpha production and interleukin-1 alpha binding sites in mouse brain during rabies infection.

We have evaluated the effect of rabies virus infection on interleukin-1 alpha (IL-1 alpha) production and its receptors in mouse brain. Study of virus dissemination in the central nervous system (CNS) showed a massive infection of main brain structures from day 4 post infection (p.i.) up to the agony stage on day 6 p.i. At the same time, IL-1 alpha concentrations increased in cortical and hippocampal homogenates, whereas no change was detected in serum. In non-infected mice, IL-1 alpha binding sites were observed in the dentate gyrus, the cortex, the choroid plexus, the meninges and the anterior pituitary. During rabies virus infection, a striking decrease in IL-1 alpha binding sites was observed on day 4 p.i. with a complete disappearance on day 6 p.i., except in the pituitary gland where they remained at control level. In conclusion, concomitantly with the early rabid pathological signs, brain IL-1 alpha production and IL-1 alpha binding sites are specifically and significantly altered by brain viral proliferation. These results indicate that IL-1 alpha could be involved in the brain response to viral infection as a mediator and could participate in the genesis of the rabies pathogeny.

Rat interleukin-1 beta binding sites in rat hypothalamus and pituitary gland.

In this study, radiolabeled recombinant rat interleukin-1 beta (r125I-IL-1 beta) was used to localize and characterize IL-1 beta binding in rat hypothalamus and pituitary gland by quantitative autoradiography. The ability of this ligand to bind to type I IL-1 receptor was first tested on murine lymphoma cells (EL-4). In the rat-tissue sections, high densities of specific r125I-IL-1 beta binding sites were localized in the anterior as well as the posterior pituitary and in the choroid plexus. A fine labeling was observed in meninges and third ventricle walls while no binding was detected in the hypothalamic nuclei. Saturation experiments, in the anterior and posterior pituitary, revealed one specific binding site with an affinity constant (Kd) of 0.5 nM. Competition experiments were achieved using either rat IL-1 beta (rIL-1 beta) or human IL-1s (hIL-1 alpha, hIL-1 beta and IL-1 receptor antagonist: hIL-1a). Affinity constants (Ki) were drastically different according to the ligand used, while Ki values were found similar in anterior and posterior pituitary. Competition with rIL-1 beta revealed one binding affinity (Ki of 0.1 nM range). In contrast, competition with hIL-1 beta revealed two binding affinities: a high (Ki: 0.1 pM range) and a low one (Ki: 1 nM range). Competition with hIL-1ra was obtained for high concentrations only (Ki: 10-100 nM range), whereas human IL-1 alpha (hIL-1 alpha) was unable to compete at 1-100 nM.(ABSTRACT TRUNCATED AT 250 WORDS)