Riboflavin did not provide anti-inflammatory or antioxidant effects in an experimental model of sepsis

We aimed to evaluate whether the administration of riboflavin to septic animals reduces inflammation, oxidative stress, organ dysfunction, and mortality. C57BL/6 mice, 6-8 weeks old, were allocated to the study group (polymicrobial sepsis induced by cecal ligation and puncture (CLP) + antibiotic + iv riboflavin), control (CLP + antibiotic + iv saline), or naïve (non-operated controls). Serum concentrations of alanine aminotransferase (ALT), creatine kinase-MB (CK-MB), urea, and creatinine, and markers of inflammation [interleukin (IL)-6, tumor necrosis factor (TNF)-α, keratinocyte-derived chemokine (KC), and macrophage inflammatory protein (MIP)-2)], and oxidative stress (malondialdehyde (MDA) were measured 12 h after the experiment. Animal survival rates were calculated after 7 days. Means between groups were compared using linear regression models adjusted under the Bayesian approach. No significant difference was observed between control and study groups in serum concentrations of IL-6 (95% credible interval) (-0.35 to 0.44), TNF-α (-15.7 to 99.1), KC (-0.13 to 0.05), MIP-2 (-0.84 to 0.06), MDA (-1.25 to 2.53), or ALT (-6.6 to 11.5). Serum concentrations of CK-MB (-145.1 to -30.1), urea (-114.7 to -15.1), and creatinine (-1.14 to -0.01) were higher in the study group. Survival was similar in both groups (P=0.8). Therefore, the use of riboflavin in mice undergoing sepsis induced by CLP did not reduce inflammation, oxidative stress, organ dysfunction, or mortality compared with placebo.

Biomass smoke COPD has less tomographic abnormalities but worse hypoxemia compared with tobacco COPD

Special attention has emerged towards biomass smoke-induced chronic obstructive pulmonary disease (COPD), providing new knowledge for prevention and therapeutic approach of non-smoker COPD patients. However, the understanding of biomass smoke COPD is still limited and somewhat controversial. The aim of the present study was to compare COPD exclusively caused by tobacco smoking with COPD exclusively caused by environmental or occupational exposures. For this cross-sectional study, COPD patients were recruited from outpatient clinics and formed two groups: non-smoker COPD group (n=16) with exposure to biomass smoke who did not smoke cigarette and tobacco smoker COPD group (n=15) with people who did not report biomass smoke exposure. Subjects underwent pulmonary function tests, thoracic high-resolution computed tomography, 6-min walk test, and sputum induction. The non-smoker COPD group had biomass smoke exposure of 133.3±86 hour-years. The tobacco COPD group smoked 48.5±27.4 pack-years. Women were 62.5 and 66.7%, respectively, of non-smokers and smokers. The non-smoker COPD group showed higher prevalence of dyspnea, lower arterial oxygen tension (PaO2), and lower arterial oxygen saturation (SaO2%) with similar spirometry results, lung volumes, and diffusion capacity. Regarding inflammatory biomarkers, differences were detected in sputum number of lymphomononuclear cells and in sputum concentrations of interleukin (IL)-6 and IL-8 with higher values in the smoker group. Emphysema was more prevalent in the tobacco smoker group, which also showed higher relative bronchial wall thickness and lower lung density by quantitative analysis. Biomass smoke induced more hypoxemia compared to tobacco in COPD patients with similar severity.

An interleukin-33/ST2 signaling deficiency reduces overt pain-like behaviors in mice

Interleukin (IL)-33, the most recent member of the IL family of cytokines, signals through the ST2 receptor. IL-33/ST2 signaling mediates antigen challenge-induced mechanical hyperalgesia in the joints and cutaneous tissues of immunized mice. The present study asked whether IL-33/ST2 signaling is relevant to overt pain-like behaviors in mice. Acetic acid and phenyl-p-benzoquinone induced significant writhing responses in wild-type (WT) mice; this overt nociceptive behavior was reduced in ST2-deficient mice. In an antigen-challenge model, ST2-deficient immunized mice had reduced induced flinch and licking overt pain-like behaviors. In the formalin test, ST2-deficient mice also presented reduced flinch and licking responses, compared with WT mice. Naive WT and ST2-deficient mice presented similar responses in the rota-rod, hot plate, and electronic von Frey tests, indicating no impairment of motor function or alteration in basal nociceptive responses. The results demonstrate that IL-33/ST2 signaling is important in the development of overt pain-like behaviors.

Effect of endogenous hydrogen sulfide inhibition on structural and functional renal disturbances induced by gentamicin

Animal models of gentamicin nephrotoxicity present acute tubular necrosis associated with inflammation, which can contribute to intensify the renal damage. Hydrogen sulfide (H2S) is a signaling molecule involved in inflammation. We evaluated the effect of DL-propargylglycine (PAG), an inhibitor of endogenous H2S formation, on the renal damage induced by gentamicin. Male Wistar rats (N = 8) were injected with 40 mg/kg gentamicin (im) twice a day for 9 days, some of them also received PAG (N = 8, 10 mg·kg-1·day-1, ip). Control rats (N = 6) were treated with saline or PAG only (N = 4). Twenty-four-hour urine samples were collected one day after the end of these treatments, blood samples were collected, the animals were sacrificed, and the kidneys were removed for quantification of H2S formation and histological and immunohistochemical studies. Gentamicin-treated rats presented higher sodium and potassium fractional excretion, increased plasma creatinine [4.06 (3.00; 5.87) mg percent] and urea levels, a greater number of macrophages/monocytes, and a higher score for tubular interstitial lesions [3.50 (3.00; 4.00)] in the renal cortex. These changes were associated with increased H2S formation in the kidneys from gentamicin-treated rats (230.60 ± 38.62 µg·mg protein-1·h-1) compared to control (21.12 ± 1.63) and PAG (11.44 ± 3.08). Treatment with PAG reduced this increase (171.60 ± 18.34), the disturbances in plasma creatinine levels [2.20 (1.92; 4.60) mg percent], macrophage infiltration, and score for tubular interstitial lesions [2.00 (2.00; 3.00)]. However, PAG did not interfere with the increase in fractional sodium excretion provoked by gentamicin. The protective effect of PAG on gentamicin nephrotoxicity was related, at least in part, to decreased H2S formation.

Streptozotocin-induced mechanical hypernociception is not dependent on hyperglycemia

Since streptozotocin (STZ)-induced diabetes is a widely used model of painful diabetic neuropathy, the aim of the present study was to design a rational protocol to investigate whether the development of mechanical hypernociception induced by STZ depends exclusively on hyperglycemia. Male Wistar rats (180-200 g; N = 6-7 per group) received a single intravenous injection of STZ at three different doses (10, 20, or 40 mg/kg). Only the higher dose (40 mg/kg) induced a significant increase in blood glucose levels, glucose tolerance and deficiency in weight gain. However, all STZ-treated rats (hyperglycemic or not) developed persistent (for at least 20 days) and indistinguishable bilateral mechanical hypernociception that was not prevented by daily insulin treatment (2 IU twice a day, sc). Systemic morphine (2 mg/kg) but not local (intraplantar) morphine treatment (8 µg/paw) significantly inhibited the mechanical hypernociception induced by STZ (10 or 40 mg/kg). In addition, intraplantar injection of STZ at doses that did not cause hyperglycemia (30, 100 or 300 µg/paw) induced ipsilateral mechanical hypernociception for at least 8 h that was inhibited by local and systemic morphine treatment (8 µg/paw or 2 mg/kg, respectively), but not by dexamethasone (1 mg/kg, sc). The results of this study demonstrate that systemic administration of STZ induces mechanical hypernociception that does not depend on hyperglycemia and intraplantar STZ induces mechanical sensitization of primary sensory neurons responsive to local morphine treatment.

A model of hemorrhagic cystitis induced with acrolein in mice

Acrolein is a urinary metabolite of cyclophosphamide and ifosfamide, which has been reported to be the causative agent of hemorrhagic cystitis induced by these compounds. A direct cytotoxic effect of acrolein, however, has not yet been demonstrated. In the present study, the effects of intravesical injection of acrolein and mesna, the classical acrolein chemical inhibitor, were evaluated. Male Swiss mice weighing 25 to 35 g (N = 6 per group) received saline or acrolein (25, 75, 225 æg) intravesically 3, 6, 12, and 24 h before sacrifice for evaluation of bladder wet weight, macroscopic and histopathological changes by Gray's criteria, and 3 and 24 h for assessment of increase in vascular permeability. In other animals, mesna was administered intravesically (2 mg) or systemically (80 mg/kg) 1 h before acrolein. Intravesical administration of acrolein induced a dose- and time-dependent increase in vascular permeability and bladder wet weight (within 3 h: 2.2- and 21-fold increases in bladder wet weight and Evans blue dye exuded, respectively, at doses of 75 æg/bladder), as confirmed by Gray's criteria. Pretreatment with mesna (2-mercaptoethanesulfonic acid), which interacts with acrolein resulting in an inactive compound, inhibited all changes induced by acrolein. Our results are the first demonstration that intravesical administration of acrolein induces hemorrhagic cystitis. This model of acrolein-induced hemorrhagic cystitis in mice may be an important tool for the evaluation of the mechanism by which acrolein induces bladder lesion, as well as for investigation of new uroprotective drugs.

Trypanosoma cruzi infection and/or administration of the nonsteroidal anti-inflammatory nimesulide increase the number of colonic crypts overexpressing metallothioneins in rat colon carcinogenesis

Trypanosoma cruzi infection and nonsteroidal anti-inflammatory drugs inhibit colorectal carcinogenesis by mechanisms not completely known and metallothionein proteins (MTs) may be involved in this process. Sixty-six male Wistar rats weighing 90 to 120 g were randomly divided into seven groups (GI to GVII). GI, GII and GIII animals were subcutaneously infected with 200,000 trypomastigote forms of the Y strain of T. cruzi. After 8 weeks, GI, GII, GIV, and GVI were injected with one weekly subcutaneous dose of 12 mg/kg dimethylhydrazine for 4 weeks. In sequence, GI, GIV and GV were treated with nimesulide (10 mg/kg per dose, five times per week for 8 weeks). Groups I, III, IV, and VI had 12 animals, and each of the other groups had 6 animals. All the animals were euthanized 8 weeks after the last dimethylhydrazine injection. The colons were fixed and processed for MT immunohistochemistry. The index of MT-overexpressing colonic crypts (MTEC) was estimated as the percentage of MT-stained crypts in relation to the total number of crypts scored. Five hundred crypts per animal were scored. Data were analyzed by the Kruskal-Wallis test followed by the Dunn test. There was an increase in MTEC index in the groups either infected with T. cruzi or treated with nimesulide or both infected and treated when compared to control (401, 809, and 1011 percent, respectively). We suggest that the increased formation of MTEC may be related to the protection against carcinogenesis provided both by T. cruzi infection and nimesulide.

Evidence for the participation of nitric oxide in pemphigus

Pemphigus is an inflammatory autoimmune disorder of the skin. Nitric oxide (NO) is an inflammatory mediator linked to a variety of physiological and pathophysiological phenomena that include skin tumors, psoriasis, urticaria, and atopic dermatitis. Inflammatory cells present in pemphigus lesions are important sources of NO production. We investigated whether NO is involved in pemphigus. A prospective cohort study was conducted at the Dermatology Service of the Hospital Universitário Walter Cantídio of the Federal University of Ceará. All patients seen at the outpatient clinic between August 2000 and July 2001, with a clinically and histologically confirmed diagnosis of pemphigus were included. The median age was 42.5 years (range: 12-69 years) with a male to female ratio of 3:2. Total serum nitrite levels, used as a marker for NO production, were determined by the Griess reaction. Skin biopsies from pemphigus and breast surgery (control) patients were used for the detection of the inducible NO synthase (iNOS) by immunohistochemistry. Twenty-two (22) patients with pemphigus and eight (8) controls who did not differ in demographic characteristics were included. Total serum nitrite levels were significantly higher (>7 æmol/L) in pemphigus patients compared to controls (<6 æmol/L), regardless of the severity of the clinical activity of pemphigus (P < 0.0001). All pemphigus biopsies presented increased immunostaining for iNOS that was not detected in normal skin samples. These data are the first to demonstrate that pemphigus patients display increased serum NO levels that are associated with increased iNOS expression in the affected skin.

Glutathione and the redox control system trypanothione/trypanothione reductase are involved in the protection of Leishmania spp. against nitrosothiol-induced cytotoxicity

Glutathione is the major intracellular antioxidant thiol protecting mammalian cells against oxidative stress induced by oxygen- and nitrogen-derived reactive species. In trypanosomes and leishmanias, trypanothione plays a central role in parasite protection against mammalian host defence systems by recycling trypanothione disulphide by the enzyme trypanothione reductase. Although Kinetoplastida parasites lack glutathione reductase, they maintain significant levels of glutathione. The aim of this study was to use Leishmania donovani trypanothione reductase gene mutant clones and different Leishmania species to examine the role of these two individual thiol systems in the protection mechanism against S-nitroso-N-acetyl-D,L-penicillamine (SNAP), a nitrogen-derived reactive species donor. We found that the resistance to SNAP of different species of Leishmania was inversely correlated with their glutathione concentration but not with their total low-molecular weight thiol content (about 0.18 nmol/10(7) parasites, regardless Leishmania species). The glutathione concentration in L. amazonensis, L. donovani, L. major, and L. braziliensis were 0.12, 0.10, 0.08, and 0.04 nmol/10(7) parasites, respectively. L. amazonensis, that have a higher level of glutathione, were less susceptible to SNAP (30 and 100 µM). The IC50 values of SNAP determined to L. amazonensis, L. donovani, L. major, and L. braziliensis were 207.8, 188.5, 160.9, and 83 µM, respectively. We also observed that L. donovani mutants carrying only one trypanothione reductase allele had a decreased capacity to survive (40 percent) in the presence of SNAP (30-150 µM). In conclusion, the present data suggest that both antioxidant systems, glutathione and trypanothione/trypanothione reductase, participate in protection of Leishmania against the toxic effect of nitrogen-derived reactive species.

Effects of lidocaine on lipopolysaccharide-induced synovitis in horses

Injetou-se lidocaína (100mg 2%) na articulação do carpo para avaliar a resposta inflamatória induzida pela injeção (1,5ng) intra-articular de lipopolissacarídeo (LPS) de E. coli. Utilizaram-se 17 cavalos Mangalarga não castrados, entre dois e três anos, divididos em três grupos. No carpo esquerdo (CE) administrou-se solução fisiológica a 0,9% (SAL) e no carpo direito (CD) uma das seguintes combinações: grupo A (n=6) LPS mais SAL, grupo B (n=6) LPS mais lidocaína e grupo C (n=5)lidocaína mais SAL. Amostras do líquido sinovial e de sangue foram colhidas imediatamente antes da injeção de LPS (T0) e às 1,30 (T1), 3 (T2), 6 (T3), 12 (T4) e 36 horas (T5) após a injeção. Variáveis clínicas e físicas, e características bioquímicas e celulares do líquido sinovial foram avaliadas nos mesmos tempos. A resposta inflamatória local e sistêmica foi mensurada pela concentração do TNF- α no soro e líquido sinovial. Observou-se aumento da concentração do TNF- α nas articulações injetadas com LPS às 3h no grupo A e de 1,30 às 3h no grupo B. Concluiu-se que o LPS induziu o processo inflamatório e que a lidocaína.

An electronic pressure-meter nociception paw test for rats

The objective of the present investigation was to compare the sensitivity of an electronic nociceptive mechanical paw test with classical mechanical tests to quantify the intensity variation of inflammatory nociception. The electronic pressure-meter test consists of inducing the hindpaw flexion reflex by poking the plantar region with a polypropylene pipette tip adapted to a hand-held force transducer. This method was compared with the classical von Frey filaments test and with the rat paw constant pressure test, a modification of the Randall and Selitto test developed by our group. When comparing the three methods, the electronic pressure-meter and the rat paw constant pressure test, but not the von Frey filaments test, detected time vs treatment interactions in prostaglandin E2 (PGE2)-induced hypernociception. Both methods also detected the PGE2-induced hypernociception in dose- (50-400 ng/paw) and time- (1-4 h) dependent manners, and time vs treatment interactions induced by carrageenin (25-400 µg/paw). Furthermore, the electronic pressure-meter test was more sensitive at early times, whereas the constant pressure test was more sensitive at later times. Moreover, the electronic pressure-meter test detected the dose-dependent antinociceptive effect of local indomethacin (30-300 µg/paw) and dipyrone (80-320 µg/paw) on carrageenin- (200 µg/paw) and PGE2- (100 ng/paw) induced hypernociception, respectively, and also detected the ineffectiveness of indomethacin (300 µg) on the effect of PGE2. Our results show that the electronic pressure-meter provides a sensitive, objective and quantitative mechanical nociceptive test that could be useful to characterize new nociceptive inflammatory mediators and also to evaluate new peripheral analgesic substances.

An electronic pressure-meter nociception paw test for mice

The aim of the present investigation was to describe and validate an electronic mechanical test for quantification of the intensity of inflammatory nociception in mice. The electronic pressure-meter test consists of inducing the animal hindpaw flexion reflex by poking the plantar region with a polypropylene pipette tip adapted to a hand-held force transducer. This method was compared to the classical von Frey filaments test in which pressure intensity is automatically recorded after the nociceptive hindpaw flexion reflex. The electronic pressure-meter and the von Frey filaments were used to detect time versus treatment interactions of carrageenin-induced hypernociception. In two separate experiments, the electronic pressure-meter was more sensitive than the von Frey filaments for the detection of the increase in nociception (hypernociception) induced by small doses of carrageenin (30 µg). The electronic pressure-meter detected the antinociceptive effect of non-steroidal drugs in a dose-dependent manner. Indomethacin administered intraperitoneally (1.8-15 mg/kg) or intraplantarly (30-300 µg/paw) prevented the hypersensitive effect of carrageenin (100 µg/paw). The electronic pressure-meter also detected the hypernociceptive effect of prostaglandin E2 (PGE2; 10-100 ng) in a dose-dependent manner. The hypernociceptive effect of PGE2 (100 ng) was blocked by dipyrone (160 and 320 µg/paw) but not by intraplantar administration of indomethacin (300 µg/paw). The present results validate the use of the electronic pressure-meter as more sensitive than the von Frey filaments in mice. Furthermore, it is an objective and quantitative nociceptive test for the evaluation of the peripheral antinociceptive effect of anti-inflammatory analgesic drugs, which inhibit prostaglandin synthesis (indomethacin) or directly block the ongoing hypernociception (dipyrone).

Decreased gastric tone and delayed gastric emptying precede neutrophil infiltration and mucosal lesion formation in indomethacin-induced gastric damage in rats

Gastric antral dysmotility has been implicated in the pathogenesis of indomethacin-induced gastric damage, but the relationship between gastric motor abnormalities and mucosal lesions has not been extensively studied. We investigated whether changes in gastric tone and gastric retention correlate with mucosal lesions and neutrophil migration in indomethacin-induced gastric damage in rats. Indomethacin, either 5 or 20 mg/kg (INDO-5 and INDO-20), was instilled into the stomach, and then gastric damage, neutrophil migration, gastric tone and gastric retention were assessed 1 or 3 h later. Gastric damage was calculated as the sum of the lengths of all mucosal lesions, and neutrophil migration was measured by assaying myeloperoxidase activity. Gastric tone was determined by a plethysmometric method, and gastric retention of either saline or Sustacal« was evaluated by a scintigraphic method. Gastric damage was detectable 3 h after either INDO-5 or INDO-20, but not after 1 h. Neutrophil migration was significantly higher 3 h after INDO-20 as compared with INDO-5 or control group, but not after 1 h. Values of gastric tone 1 and 3 h after either INDO-5 (1 h = 1.73 ± 0.07 ml; 3 h = 1.87 ± 0.03 ml) or INDO-20 (1 h = 1.70 ± 0.02 ml; 3 h = 1.79 ± 0.03 ml) were significantly lower than in controls (1 h = 1.48 ± 0.05 ml; 3 h = 1.60 ± 0.06 ml). Gastric retention of saline was higher 1 h after INDO-5 (58.9 ± 3.3 percent) or INDO-20 (56.1 ± 3.1 percent) compared to control (45.5 ± 1.7 percent), but not after 3 h. There were no differences concerning gastric retention of Sustacal« between the various groups. Indomethacin induced decreased gastric tone and delayed gastric emptying, which precede mucosal lesion and neutrophil infiltration. These results indicate that there is no relationship between these gastric motor abnormalities and mucosal lesion in indomethacin-induced gastropathy

Desenvolvimento de modelo de peritonite bacteriana para avaliaçäo do tratamento mediante acesso laparotômico e video-laparoscópico / Development a model of bacterial peritonites for the treatments through laparotomy and video-laparoscopy

Introduçäo: O emprego do acesso videolaparoscópico no tratamento das afecçöes digestivas que cursam com peritonite generalizada é motivo de controvérsia. Objetivo: Desenvolver um modelo de peritonite bacteriana para avaliaçäo do tratamento mediante acesso laparotômico e videolaparoscópico. Métodos: Ratos machos Wistar foram submetidos à ligadura de ceco (CLP) sob molde rígido de 3mm de diâmetro; na seqüência foram feitas 14 punçöes no ceco com agulha 15X10. Após 6 horas de induçäo da peritonite, os animais foram tratados mediante laparotomia ou videolaparoscopia e avaliados com base nas hemoculturas e na taxa de mortalidade. O tratamento consistiu de tiflectomia seguida ou näo de lavagem da cavidade peritoneal com soluçäo fisiológica. Resultado: A mortalidade após CLP sem tratamento foi de 90 por cento em uma semana. As hemoculturas positivas para bactérias após 3 horas variaram de 80 a 100 por cento e após 24 horas de 60 a 80 por cento, nos animais tratados com laparotomia sem lavagem do peritôneo e com videolaparoscopia seguida ou näo de lavagem peritoneal. Todavia, a mortalidade após laparotomia foi de 20 por cento e após videolaparoscopia foi de 80 por cento. Conclusäo: O modelo experimental desenvolvido induz a peritonite grave, e a bacteremia associada ao tratamento videolaparoscópico tem alta letalidade.

Differential production of nitric oxide by endotoxin-stimulated rat and mouse neutrophils

There is controversy regarding the evidence for the production of nitric oxide (NO) by neutrophils (PMNs). The present study investigates NO production, as assessed by the biosynthesis of the end products, nitrite and nitrate, in the pellets and supernatants of rat and mouse peripheral blood neutrophils obtained during endotoxemia and of peritoneal carrageenin-elicited PMNs stimulated in vitro with E. coli lipopolysaccharide (LPS). We also investigated the induction of NO synthase by rat and mouse peritoneal cells. The intraperitoneal (ip) administration of LPS to mice (10 mg/kg) and rats (5 mg/kg) significantly increased plasma nitrate concentration by six and 23-fold, respectively. In vivo pretreatment with L-NGmonomethyl arginine (L-NMMA) significantly inhibited this production. Compared to animals injected with PBS, the cell pellets of blood PMNs obtained from mice, but not rats, 2 or 6 h after LPS administration produced significant amounts of nitrite (14 ñ 3 and 18 ñ 2 nmol/mg protein, respectively). Little or no nitrite was found in the incubating medium. In contrast, 6 h after a carrageenin challenge (700 mug) peritoneal neutrophils obtained from rats, but not mice, released high concentrations of nitrite into the supernatant during a 24-h period of incubation (34 ñ 0.8 muM). The nitrite concentration of the pellet of these cells was negligible. In contrast to the lack of increase in the amount of nitrite released into the supernatants, the in vitro stimulation of rat PMNs with LPS (10 muglml) for 24 h did increase intracellular nitrite concentration (from 0.8 ñ 0.07 to 8 ñ 0.3 nmol/mg protein). In mouse PMNs, LPS treatment caused only a small release of nitrite into the incubation medium (14 ñ I muM). There was no significant change in nitrite concentration in the cell pellets. These data suggest that rat and mouse neutrophils differ in their ability to produce nitric oxide following stimulation with endotoxin.

Participation of TNF-Ó and IL-1 in the pathogenesis of cyclophosphamide-induced hemorrhagic cystitis

The involvement of cytokines TNF-Ó and IL-1 has been investigated in a model of cyclophosphamide (CYP) - induced hemorrhagic cystitis. Male Swiss mice (25-30 g) received CYP in a single ip dose of 100, 200 or 400 mg/kg and were sacrificed 6, 12, 24, 48 and 72 h later. Cystitis was evaluated by determining the changes in bladder wet weight (BW) and plasma protein extravasation (PPE, measured by the Evans blue leakage technique). CYP treatment induced a marked increase in BW and in PPE, which was significant within 6 h and reached maximal values within 12 h (BW, 118 percent, P<0.05; N = 11; and PPE, 824 percent, P<0.05; N = 11), continuing to be significant until 48 h. Pretreatment of animals with whole anti-TNF-Ó serum (25 or 50 µl diluted in 500 µl 0.9 percent saline, ip, 30 min earlier caused a significant reduction in the CYP-induced BW increase in 6-h and 12-h cystitis (82 percent and 91 percent, respectively, P<0.05; N = 6) and...

Tumor necrosis factor accounts for the neutrophil emigration activity released by cultured malignant fibrous histiocytoma cells

Cultured malignant fibrous histiocytoma (MFH) cells obtained from a spontaneous and transplantable rat tumor were studied for their ability to release tumor necrosis factor (TNF) and a factor which induces neutrophil migration in vivo. MFH cells obtained from 7-day cultures spontaneously released both activities into the supernatant (TNF: 36 ñ 9 iu tnf/ml supernatant, N = 3; neutrophil chemoattractant factor: control, Medium ip: 6 ñ 1 x 10**6; MFH supernatant: 18 ñ 1 x 106 neutrophils/cavity, H = 5). these releases were enhanced by treating MFH cells with LPS (TNF; 61 percent; neutrophil chemoattractant factor: 46 percent) and were abolished by the glucocorticoid dexamethasone (TNF: 68 percent; neutrophil chemoattractant factor: 100 percent). Anti-TNF antiserum abolished the neutrophil chemoattractant activity of the supernatants (95 percent). The release of TNF or neutrophil chemoattractant activity was reduced in cells obtained from older cultures (14 and 21 days) (TNF: 7-day culture, 36 ñ 9;14-day culture, 19ñ2;21-day culture, 19ñ 1 IU of TNF/ml; neutrophil chemoattractant activity: 7-day culture, 18 ñ 1.6; 14-day culture, 13 ñ 3;28-day culture, 8 ñ 1 x 10**6 neutrophils/cavity). The predominant cells present in 7-day cultures of MFH were histiocyte-like cells as determined by nonspecific esterase methods. The number of these cells decreased as the cultures aged (7-day culture, 71 percent; 14-day culture, 5 percent; 21-day culture, 0 percent)...

Inflammatory edema and migration of leucocytes but not phagocytosis are reduced in young rats

1. Newborn and old individuals are more susceptible to infection. In this study vascular permeability as well as the migration of neutrophils and mononuclear cells were determined in male Wistar rats aged 3, 8 and 16 weeks (N = 5-7 animals per group). The increase in vascular permeability induced by the ip injection of carrageenin in 3-week old rats was 2-fold lower than observed for 8- or 16-week old animals. 2. The migration of neutrophils and mononuclear cells into the peritoneal cavity induced by carrageenin and thioglycollate was lower in 3-week old rats (1.4 +/- 0.4 x 10(6) and 1.22 +/- 0.27 x 10(6)) compared to 8-week (4.5 +/- 0.25 x 10(6) and 4.16 +/- 0.38 x 10(6)) and 16-week old animals (5.75 +/- 1.0 x 10(6) and 5.5 +/- 0.5 x 10(6)), respectively. The number of resident cells in the peritoneal cavity of 3-week old rats was also only 15 per cent of that observed for the older rats. The reduced cell migration in younger rats was not the result of leucopenia since the white cell counts of these animals were significantly higher than that of animals aged 8 or 16 weeks (15 +/- 2 x 10(6) vs 8 +/- 1 x 10(6) and 7 +/- 1 x 10(6)/ml of blood, respectively). 3. Although the chemotactic response was lower in 3-week old rats compared to 16-week old animals, the ability of both neutrophils and macrophages from young rats to phagocytose zymosan was similar to that of older animals (60-80 per cent ).(ABSTRACT TRUNCATED AT 250 WORDS)

Macrophages stimulated with lipopolysaccharide release a selective neutrophil recruitment inhibitory factor: an in vivo demonstration

Intravenous injections of lipopolysaccharide (LPS, 20 microng/Kg) and of a factor originating from LPS-stimulated macrophage monolayers (Neutrophil Recruitment Inhibitory Factor, NRIF) inhibited neutrophil migration into peritoneal cavities induced by carrageenin in rats for up to 24 h. Mononuclear cell migration induced by thioglycollate was also inhibited by the same treatment with LPS but was not affected by NRIF. We conclude that NRIF specifically blocks neutrophil migration and we suggest that NRIF released into the circulation may constitute an important determinant of septicemia