Anti-inflammatory properties of the type 1 and type 2 vasoactive intestinal peptide receptors: role in lethal endotoxic shock

Vasoactive intestinal peptide (VIP) is a neuropeptide that can modulate several immune aspects. Previous reports showed that VIP attenuates the deleterious consequences of septic shock by inhibiting the production of pro-inflammatory agents and stimulating the production of anti-inflammatory cytokines in activated macrophages. In this study, by using selective VIP agonists, we investigated the differential involvement of the VIP receptors in the anti-inflammatory role of VIP. Both the type 1 VIP receptor (VPAC1) agonist, [K(15), R(16), L(27)] VIP 1-7-GRF 8-27, and the type 2 VIP receptor (VPAC2) agonist, Ro25-1553, protected mice from lethal endotoxemia by inhibiting the macrophage-derived pro-inflammatory mediators IL-6, TNF-alpha, IL-12 and NO, and by stimulating the production of the anti-inflammatory cytokine IL-10. In addition, both VIP and VPAC1 agonist, but not the VPAC2 agonist, reduced in vitro and in vivo the expression of the co-stimulatory B7. 1/B7.2 molecules, and the subsequent stimulatory activity for T helper cells in stimulated macrophages. The higher effectiveness of the VPAC1 agonist compared with the VPAC2 agonist suggests that VPAC1 is the major mediator of the anti-inflammatory action of VIP. Since VIP and the two agonists appear to affect multiple cytokines and inflammatory factors, they might provide a more efficient therapeutical alternative to the use of specific cytokine antibodies or antagonists.

Neuroregulation of growth hormone during exercise in children

Physical exercise is an important physiological stimulus to growth hormone (GH) release in man. Many neurotransmitters are involved in GH regulation. We studied the effect of the cholinergic pathway on GH secretion induced by physical exercise. Particularly, we studied the effect of a cholinergic muscarinic agonist on GH-induced physical exercise, both in children and adults. Moreover, we investigated the refractoriness of GH secretion after a second physical exercise stimulus. Three different protocols were performed: 1) GH response to physical exercise in children and adults; 2) effect of pyridostigmine on exercise-induced GH secretion in children and adults; 3) GH response to two consecutive exercises in children and adults. Our data show that in children GH peak after physical exercise is higher than in adults. Pyridostigmine enhances GH release in children and in adults. Exercise stimulus was able to release GH in the second test only in children, while the refractory phase did not permit a new GH release in adults. The shift to a modality of neural control of GH secretion peculiar of adults is likely due to neuroregulatory mechanisms which may be partly dependent on long-term variation in hormonal milieu.

Insulin-dependent phosphorylation of a 70-kDa protein in light microsomes from rat adipocytes

In order to discover possibly novel insulin receptor substrates and/or downstream targets in the insulin signaling pathway, we established a cell-free system for this purpose using purified insulin receptor and subcellular fractions from rat adipocytes as a sourse of cellular substrates. Under these conditions, we have found a 70-kDa protein (pp70) in fat cells that is tyrosine-phosphorylated by the activated insulin receptor. Using sucrose velocity gradient sedimentation we also show that pp70 cofractionate a particulate fraction containing IRS-1 but not with GLUT-4 vesicle-enriched fractions. Our results suggest that pp70 may be an endogenous substrate for the insulin receptor tyrosine kinase.

[Clinical case of the month. An unusual presentation of superior vena cava syndrome]

We report the case of a 48-year-old man who was admitted to our emergency department because of a superior vena caval syndrome from which the symptoms occurred only during exercise. His past history included an episode of lower limb deep venous thrombosis. Because an atrio-ventricular partial block was fortuitously evidenced, the patient was submitted to a pacemaker insertion. A few years later, the patient suffered from rapid dyspnea on exercise, associated with facial cyanosis and systemic hypotension. The exploration by phlebography evidenced that the inferior vena cava was completely obstructed. Therefore the venous return from the lower part of the body to right heart was obtained through hypertrophy of the vena azygos. In addition, the presence of cardiac pacing electrodes induced a stenosis at the level of the superior vena cava, just before its entrance into the right atrium. Such a venous network accounted for the occurrence of a chronic superior vena caval syndrome associated with peripheral arterial hypotension during exercise. Treatment consisted of a superior vena caval percutaneous transluminal balloon angioplasty followed by a Wallstent insertion. This procedure led to a correction of all hemodynamic abnormalities responsible for reported pathophysiological limitations to stress.

Types of fat intake and body mass index in a Mediterranean country

BACKGROUND

Although the fatty acid fractions provide similar metabolizable energy, the type of dietary fat consumed could be relevant to the development of obesity.

OBJECTIVE

To investigate the relationship between body mass index (BMI), obesity and the consumption of different types of fat and olive oil in a Mediterranean country with high prevalence of obesity, and high intake of monounsaturated fatty acids (MUFA) and olive oil.

SUBJECTS

The study was carried out in Spain among 23 289 women and 14 374 men, aged 29-69 years, who were participants of a large European prospective cohort.

METHODS

: Information on usual food intake was collected by interviewers by means of a dietary history questionnaire. The association between obesity (BMI >/= 30 kg m2), dietary fat, other dietary patterns and other non-dietary factors were tested using multilinear regression analysis. The ratio of reported energy intake to energy requirement was used as an estimation of dietary underreporting.

RESULTS

The association between fatty acid fractions intake (saturated fatty acids (SFA) in women, and MUFA and polyunsaturated fatty acids (PUFA) in both sexes) and BMI was very weak, accounting for less than 1% of variance. All dietary and non-dietary variables accounted for 21% of variance in the measurement of BMI in women and only 6.7% of variance in men. Estimated underreporting of energy intake was 17.5% in obese women and 5.5% in obese men.

CONCLUSIONS

The association between consumption of specific types of dietary fat, olive oil and obesity in Spain is not very important. However, because of the cross-sectional design and some level of underreporting of energy intake observed in overweight subjects and overreporting in underweight subjects, systematic bias cannot be completely discarded.

The mouse (Mus musculus) immunoglobulin kappa variable (IGKV) genes and joining (IGKJ) segments

The 'Mouse (Mus musculus) Immunoglobulin Kappa Variable (IGKV) Genes and Joining (IGKJ) Segments', third report of the 'IMGT Locus on Focus' section, comprises four tables entitled: (1) 'Mouse (Mus musculus) germline IGKV gene table'; (2) 'Correspondence between Mouse (Mus musculus) IMGT IGKV subgroups and previous designations'; (3) 'Mouse (Mus musculus) germline IGKJ table', and (4) 'Mouse (Mus musculus) IGKJ allele table'. These tables are available at the IMGT Marie-Paule page from IMGT, the international ImMunoGeneTics database (http://imgt.cnusc.fr:8104) created by Marie-Paule Lefranc, CNRS, Université Montpellier II, Montpellier, France.

Separating the retinal electrophysiologic effects of vigabatrin: treatment versus field loss

OBJECTIVE

To separate the retinal electrophysiologic markers associated with vigabatrin-attributed visual field loss (VGB-VFL) from those associated with current vigabatrin therapy.

METHODS

A nonrandomly selected cohort of 8 previous and 18 current vigabatrin users and a reference cohort of 8 never vigabatrin-treated patients with epilepsy receiving other antiepilepsy drugs (AED) underwent electro-oculography (EOG), electroretinography (ERG), and automated static threshold perimetry. A cohort of 22 normal subjects underwent ERG. The validity of the retinal electrophysiologic variables to detect the presence and severity of VGB-VFL was assessed using receiver operator characteristic curves.

RESULTS

Of 26 patients exposed to vigabatrin, 18 exhibited VGB-VFL. No patients receiving alternative AED showed this type of visual field abnormality. The presence and severity of VGB-VFL was significantly associated with the latency (implicit time) and amplitude of the ERG cone function. The amplitude of the cone flicker response was the strongest predictor of VGB-VFL and revealed a sensitivity of 100% at a specificity of 75%. The EOG, the photopic and scotopic ERG, and the latency of the ERG second oscillatory potential (OP2) were not significantly related to the presence of VGB-VFL. Vigabatrin therapy was significantly associated with the photopic amplitude, the scotopic a-wave latency, and the latency of OP2.

CONCLUSION

In patients who cannot perform reliable perimetry, the cone-specific ERG flicker amplitude provides the best screening method for detecting VGB-VFL.

Mobilization kinetics of peripheral blood progenitor cells after IAPVP-16 salvage chemotherapy plus G-CSF in lymphoproliferative disorders

We have explored the efficacy of salvage chemotherapy combination, IAPVP-16 (ifosfamide 5 g/m2 on day 1; VP-16 100 mg/m2 on days 1-3; ara-C 1.2 g/m2/12 h on days 1 and 2; methylprednisolone 80 mg/m2 on days 1-5) plus G-CSF for PBPC mobilization. This protocol was used in 45 patients with relapsed or refractory lymphoproliferative diseases who underwent 85 leukaphereses. In 41 patients > 2 x 106/kg CD34+ cells were obtained after a median of two procedures. The median number of CD34+ cells harvested was 3.2 x 106/kg per apheresis and 8.4 x 106/kg per patient. Seven of 10 patients who had failed previous mobilization attempts achieved more than 2 x 106 CD34+ cells/kg in a maximum of three aphereses. A history of previous mobilization failure and a low platelet count (<150 x 109/l) negatively influenced the CD34+ cell yield in univariate and multivariate analyses. A good correlation was found between the circulating CD34+ cells/microl and the CD34+ cells and CFU-GM in the leukaphereses products (r = 0.93 and r = 0.73, P < 0.001), and > or =17 CD34+ cells/microl predicted the achievement of > 2 x 106/kg CD34+ cells in a single leukapheresis in more than 90% of cases. IAPVP-16 plus G-CSF may be specially indicated in tandem transplantations or CD34+ selection and in patients who have failed previous mobilization attempts.

Salicylic acid mediated by the oxidative burst is a key molecule in local and systemic responses of cotton challenged by an avirulent race of Xanthomonas campestris pv malvacearum

We analyzed the production of reactive oxygen species, the accumulation of salicylic acid (SA), and peroxidase activity during the incompatible interaction between cotyledons of the cotton (Gossypium hirsutum) cv Reba B50/Xanthomonas campestris pv malvacearum (Xcm) race 18. SA was detected in petioles of cotyledons 6 h after infection and 24 h post inoculation in cotyledons and untreated leaves. The first peak of SA occurred 3 h after generation of superoxide (O(2)(.-)), and was inhibited by infiltration of catalase. Peroxidase activity and accumulation of SA increased in petioles of cotyledons and leaves following H(2)O(2) infiltration of cotyledons from 0.85 to 1 mM. Infiltration of 2 mM SA increased peroxidase activity in treated cotyledons and in the first leaves, but most of the infiltrated SA was rapidly conjugated within the cotyledons. When increasing concentrations of SA were infiltrated 2. 5 h post inoculation at the beginning of the oxidative burst, the activity of the apoplastic cationic O(2)(.-)-generating peroxidase decreased in a dose-dependent manner. We have shown that during the cotton hypersensitive response to Xcm, H(2)O(2) is required for local and systemic accumulation of SA, which may locally control the generation of O(2)(.-). Detaching cotyledons at intervals after inoculation demonstrated that the signal leading to systemic accumulation of SA was emitted around 3 h post inoculation, and was associated with the oxidative burst. SA produced 6 h post infection at HR sites was not the primary mobile signal diffusing systemically from infected cotyledons.

Characteristics of a unique visual field defect attributed to vigabatrin

PURPOSE

Vigabatrin (VGB) therapy is associated with a loss of peripheral vision. The characteristics and prevalence of VGB-attributed visual field loss (V-AVFL) and associated risk factors were evaluated in patients with epilepsy.

METHODS

The material comprised the visual fields and case notes of 88 patients with suspected V-AVFL (25 spontaneous reports and 63 cases from an open-label extension trial) and of 42 patients receiving alternative antiepileptic drugs (AEDs) from a cross-sectional study.

RESULTS

Forty-two reliable cases of visual field loss could not be assigned to an alternative known cause and were therefore attributed to VGB (13 spontaneous reports and 29 from the open-label study). All cases except one were asymptomatic. Seven cases of field loss were present in the reference cohort of 42 patients; all cases could be attributed to a known aetiology. Thirty-six of the 42 confirmed cases of V-AVFL exhibited a bilateral defect that was most profound nasally, and three, a concentric constriction. The prevalence of V-AVFL was 29% (95% confidence interval, 21-39%). Male gender was associated with a 2.1-fold increased relative risk of V-AVFL (95% confidence interval, 1.20-4.6%). Age, body weight, duration of epilepsy, and daily dose of VGB, and concomitant AEDs did not predict the occurrence of V-AVFL.

CONCLUSIONS

The unique visual field defect attributed to VGB is profound in terms of the frequency of occurrence and the location and severity of loss. The asymptomatic nature of the field loss indicates that V-AVFL can be elicited only by visual field examination.

An accelerated schedule for tick-borne encephalitis vaccine: the American Military experience in Bosnia

Tick-borne encephalitis (TBE) is a viral illness endemic to the Balkan region. United States military forces were deployed to Bosnia in early 1996 as part of Operation Joint Endeavor, a U.S.-led multinational peace-keeping operation. To counteract the TBE threat, an inactivated, parenteral vaccine (FSME-Immun Inject; Immuno AG, Vienna, Austria) was offered to soldiers at high risk on a volunteer basis in an accelerated, 3-dose schedule (0, 7, and 28 days). Passive adverse reaction surveillance was conducted on 3,981 vaccinated personnel. Paired sera from a randomly selected group of 1,913 deployed personnel (954 who received vaccine and 959 who were unvaccinated) were tested for antibodies to TBE by an ELISA. Three-dose recipients demonstrated an 80% seroconversion rate (4-fold or greater increase in anti-TBE titers). By comparison, the TBE infection rate in the unvaccinated cohort was found to be only 0.42% (4 of 959). Only 0.18% of vaccinees reported self-limited symptoms. An accelerated immunization schedule appears to be an acceptable option for military personnel or travelers on short-term notice to TBE-endemic areas.

[Massive feto-maternal transfusion. Report of 3 cases with review of the literature]

Massive feto maternal hemorrhage is rare. Early diagnosis is important because massive feto-maternal hemorrhage has a poor prognosis. The clinical manifestations of transplacental hemorrhage are related not only to the size of the hemorrhage but also to the time at which the hemorrhage occurs. In women who are candidates for Rh immune prophylaxis, massive feto maternal hemorrhage may be detected by Kleihauer test and we suggest that 10 micrograms dose of immune globin should be administered for each estimated ml of Rh positive blood given, to prevent an immunization Disappearance of fetal cells by Kleihauer test or appearance residual antibody suggests the adequacy of therapy. Three cases of massive fetomaternal hemorrhage (more than 225 ml) are presented here. Two mothers was Rh negative and they are delivered of rhésus positive children, which necessitated the administration of large volume of anti D. One of the cases shows the possibility of association between choriocarcinoma and positive kleihauer test.

Shedding of membrane-bound CD14 from lipopolysaccharide-stimulated macrophages by vasoactive intestinal peptide and pituitary adenylate cyclase activating polypeptide

Macrophage activation and deactivation play essential roles in the initiation and maintenance of a successful immune response. Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating polypeptide (PACAP), two structurally related neuropeptides, act as macrophage deactivating factors. We reported previously that VIP and PACAP inhibit IL-6, IL-12, TNF alpha and NO production, and enhance IL-10 production, from lipopolysaccharide (LPS)-stimulated macrophages. In this study, we demonstrate that VIP and PACAP down-regulate the expression of CD14, the membrane-bound LPS receptor, by inducing its rapid shedding. The soluble CD14 released by VIP and PACAP corresponds in size to the soluble CD14 released by PMA. Neither VIP/PACAP nor PMA, affect the steady-state levels of CD14 mRNA. The CD14 shedding induced by VIP/PACAP is mediated through the PAC1 specific receptors and the major transduction pathway involves the protein kinase C (PKC). The VIP/PACAP inhibition of TNF alpha and NO occurs through both CD14-dependent and -independent mechanisms, whereas the inhibition of IL-6 production appears to be strictly CD14-dependent. The shedding of CD14 by VIP and PACAP represents an important mechanism by which these neuropeptides limit the macrophage inflammatory response.

A new potent antigen from Echinococcus granulosus associated with muscles and tegument

An immunoscreening of a cDNA library derived from the adult stage of the parasitic platyhelminth Echinococcus granulosus has been carried out with sera from infected dogs. The EgA31 clone encodes a fibrous protein which shares some sequence elements with paramyosins. The corresponding gene is present as a single copy in the genome. As revealed by an antibody obtained against a fusion protein produced in bacteria, the polypeptide has a molecular weight of 66 kDa. This polypeptide is present at all developmental stages studied and is a potent antigen during an infection by the adult stage in the dog and during cyst growth in human patients. By immunohistology, it was shown that it is present in the tegument and subtegumental parenchyma of the adult with a main location in the region of the suckers where it rapidly accumulates at the time of the head evagination. It is also present in the germinal layer of the cyst and on the protoscolex.

Incidence of tumor-cell contamination in leukapheresis products of breast cancer patients mobilized with stem cell factor and granulocyte colony-stimulating factor (G-CSF) or with G-CSF alone

We have assessed tumor contamination of peripheral blood progenitor cells (PBPC) in 203 high-risk breast cancer patients who were prospectively randomized to mobilization with stem cell factor (SCF) plus granulocyte colony-stimulating factor (G-CSF) versus G-CSF alone. The patients then received high-dose cyclophosphamide, cisplatin, and carmustine (BCNU) with PBPC support. One bone marrow aspirate obtained before treatment, one whole blood specimen obtained before cytokine infusion, and one to five leukapheresis products were tested for the presence of tumor cells by an alkaline phosphatase immunocytochemical technique with a targeted sensitivity of 1.7 tumor cells per 10(6) hematopoietic cells. Tumor cells were detected in the bone marrow, peripheral blood, and/or PBPC of 21 patients (10%). In 14 patients, bone marrow specimens were tumor-positive; in seven patients, premobilization whole blood specimens were tumor-positive, and in eight patients, leukapheresis products were tumor-positive. In five patients, repetitive or multiple specimens were tumor-positive, and in three cases, marrow, peripheral blood, and PBPC products were all tumor-positive. Nine of the patients in whom tumor cells were found in marrow or peripheral blood were clinical stage II to III and 12 were clinical stage IV. Nine of the tumor-positive patients were in the SCF + G-CSF arm and 12 were in the G-CSF arm. Tumor cells were detected in leukapheresis products of eight patients: three in the G-CSF + SCF arm and five in the G-CSF arm. We conclude that detectable tumor-cell contamination of bone marrow, peripheral blood, and/or PBPC occurred in approximately 10% of patients in this trial and was observed in stage II to III patients, as well as in stage IV patients. No significant difference could be found in the rate of PBPC tumor-cell contamination between patients who received SCF + G-CSF compared with those who received G-CSF alone. Neither mobilization regimen was found to increase the rate of tumor-cell contamination when control premobilization blood samples were compared with leukapheresis products.

[Bypass surgery vs angioplasty for coronary artery disease]

Revascularization techniques such as coronary angioplasty or coronary artery bypass surgery play a growing role in the management of coronary artery disease. Angioplasty is the treatment of choice for single coronary lesions while surgery remains the best approach for the revascularization of multivessel disease. There are some exceptions to this rule, however. Bypass surgery may be recommended for the revascularisation of proximal left anterior descending lesions and, of course, for isolated left main stenosis. On the opposite, coronary angioplasty and stenting is used more frequently in the treatment of multivessel lesions amenable to this technique. Choice of either method of revascularization is pragmatic, based on clinical, anatomical and physiological considerations and organized in the setting of a medicosurgical collaboration.

Analysis of phase-shifted fiber Bragg gratings written with phase plates

A method for obtaining phase-shifted Bragg gratings by use of phase plates is presented. A comparison of experimental and theoretical results allows us to describe the utility of such a component.

Inducible binding of cyclic adenosine 3',5'-monophosphate (cAMP)-responsive element binding protein (CREB) to a cAMP-responsive promoter in vivo

In general, DNA-binding factors that activate gene transcription are thought to do so via reversible interaction with DNA. However, most studies, largely performed in vitro, suggest that the transcriptional activator, cAMP response element-binding protein (CREB), is exceptional in that it is constitutively bound to the promoter, where its phosphorylation leads to the recruitment of CREB-binding protein (CBP) to form a CREB/CBP/promoter complex. We have studied how CREB interacts with DNA in vivo to regulate the cAMP-responsive gene encoding human CRH (hCRH). Protein-DNA complexes were cross-linked in cells expressing the endogenous hCRH gene by exposure to a 10 nsec pulse of high-energy UV-laser light, followed by immunoaffinity purification of CREB-DNA complexes. Binding of CREB to a fragment of the hCRH promoter containing a canonical, functional cAMP response element was absent in untreated cells, but was specifically induced after activation of the protein kinase A pathway with forskolin. These data indicate that, in vivo, CREB, like the majority of other DNA-binding transcriptional activators, undergoes signal-mediated promoter interaction.

HIV/AIDS mental health training for health care providers: an evaluation of three models

Three models of continuing education--full-day, half-day, and brief workshop--for health providers treating patients with HIV/AIDS were compared on measures of effectiveness with regard to knowledge, attitude, and practice outcomes. Analyses of pre- and postintervention data from two years of training events suggest consistent, modest, program effects in the full-day and half-day approaches, specifically in the area of knowledge enhancement.

Effects of pharmacological doses of nandrolone decanoate and progressive resistance training in immunodeficient patients infected with human immunodeficiency virus

This nonplacebo-controlled, open label, randomized study was conducted to test the hypotheses that pharmacological doses of nandrolone decanoate would increase lean body tissue, muscle mass, and strength in immunodeficient human immunodeficiency virus-infected men, and that these effects would be enhanced with progressive resistance training (PRT). Thirty human immunodeficiency virus-positive men with fewer than 400 CD4 lymphocytes/mm3 were randomly assigned to receive weekly injections of nandrolone alone or in combination with supervised PRT at 80% of the one-repetition maximum three times weekly for 12 weeks. Total body weight increased significantly in both groups (3.2 +/- 2.7 and 4.0 +/- 2.0 kg, respectively; P < 0.001), with increases due primarily to augmentation of lean tissue. Lean body mass determined by dual energy x-ray absorptiometry increased significantly more in the PRT group (3.9 +/- 2.3 vs. 5.2 +/- 5.7 kg, respectively; P = 0.03). Body cell mass by bioelectrical impedance analysis increased significantly (P < 0.001) in both groups (2.6 +/- 1.0 vs. 2.9 +/- 0.8 kg), but to a similar magnitude (P = NS). Significant increases in cross-sectional area by magnetic resonance imaging of total thigh muscles (1538 +/- 767 and 1480 +/- 532 mm2), quadriceps (705 +/- 365 and 717 +/- 288 mm2), and hamstrings (842 +/- 409 and 771 +/- 295 mm2) occurred with both treatment strategies (P < 0.001 for the three muscle areas); these increases were similar in both groups (P = NS). By the one-repetition method, strength increased in both upper and lower body exercises, with gains ranging from 10.3-31% in the nandrolone group and from 14.4-53.0% in the PRT group (P < 0.006 with one exception). Gains in strength were of significantly greater magnitude in the PRT group (P < or = 0.005 for all comparisons), even after correction for lean body mass. Thus, pharmacological doses of nandrolone decanoate yielded significant gains in total weight, lean body mass, body cell mass, muscle size, and strength. The increases in lean body mass and muscular strength were significantly augmented with PRT.

Biotrophic Development of Sporisorium reilianum f. sp. zeae in Vegetative Shoot Apex of Maize

ABSTRACT Sporisorium reilianum f. sp. zeae is the causal agent of maize head smut, a disease present in several regions of France. A cytological study was carried out to describe a key step of the fungal etiology, in which the mycelium invades the vegetative shoot apex. Light and transmission electron microscopy observations show that the fungus is mostly intracellular and suggest that it passes through the host cell wall by lysis and mechanical pressure. The hyphae are surrounded by an amorphous vesicle-rich layer limited by a membrane related to the host plasmalemma. The encasement can be considered as an exchange zone between the plant and the fungus. The infected host cells appear normal; therefore, the fungus seems to act like a biotrophic endophyte.

Vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide inhibit endotoxin-induced TNF-alpha production by macrophages: in vitro and in vivo studies

Vasoactive intestinal peptide (VIP) is a neuropeptide synthesized by immune cells that can modulate several immune aspects, including the function of cells involved in the inflammatory response, such as macrophages and monocytes. The production and release of cytokines by activated phagocytes are important events in the pathogenesis of ischemia-reperfusion injury. There is abundant evidence that the proinflammatory cytokine TNF-alpha is an important mediator of shock and organ failure complicating Gram-negative sepsis. VIP has been shown to attenuate the deleterious consequences of this pathologic phenomenon. In this study we have investigated the effects of VIP and the structurally related neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP38) on the production of TNF-alpha by endotoxin-activated murine peritoneal macrophages. Both neuropeptides rapidly and specifically inhibit the LPS-stimulated production of TNF-alpha, exerting their action through the binding to VPAC1 receptor and the subsequent activation of the adenylate cyclase system. VIP and PACAP regulate the production of TNF-alpha at a transcriptional level. In vitro results were correlated with an inhibition of both TNF-alpha expression and release in endotoxemic mice in vivo. The immunomodulatory role of VIP in vivo is supported by the up-regulation of VIP release in serum and peritoneal fluid by LPS and proinflammatory cytokines such as TNF-alpha, IL-1beta, and IL-6. These findings support the idea that under toxicity conditions associated with high LPS doses, VIP and PACAP could act as protective mediators that regulate the excessive release of TNF-alpha to reduce inflammation or shock.

Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activation polypeptide (PACAP) protect mice from lethal endotoxemia through the inhibition of TNF-alpha and IL-6

The neuropeptides vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) down-regulate cytokine production. Because human septic shock involves excessive cytokine production, the effect of VIP/PACAP was investigated in a high endotoxemia murine model. Both peptides protect against endotoxin-induced lethality and prevent septic shock-associated histopathological alterations. VIP/PACAP reduce serum and peritoneal TNF-alpha and IL-6, suggesting that the protective effect is exerted by inhibiting the production of endogenous TNF-alpha/IL-6. Consistent with this mechanism, VIP does not protect against septic shock induced by exogenous TNF-alpha. The immunomodulatory role of VIP in vivo is supported by the appearance of high levels of VIP in serum and peritoneal fluid following LPS administration. Thus, the neuropeptides VIP/PACAP protect from the lethal effect of high endotoxemia, presumably by down-regulating TNF-alpha and IL-6 production, and may offer an alternative in the treatment of human septic shock syndrome.