N2733, 1-[3-(3-pyridyl)-acryloyl]-2-pyrrolidinone hydrochloride inhibits LPS-induced TNF-alpha production and improves survival in endotoxemic mice

N2733, 1-[3-(3-pyridyl)-acryloyl]-2-pyrrolidinone hydrochloride, was examined for its effect on TNF-alpha production by human myeloid THP-1 cells stimulated with lipopolysaccharide (LPS). N2733 inhibited LPS-induced release of TNF-alpha from THP-1 cells with an IC50 of 11 microM. N2733 did not affect the cell viability at the concentration of 50 microM or 100 microM. This indicates that N2733 is a potent inhibitor for TNF-alpha production without severe cytotoxicity. N2733 was also studied in two murine endotoxin shock models induced with LPS. One model was DBA/2 mice injected with LPS (5.6 mg/kg, i.v.), which increased the serum level of TNF-alpha within 1 hr. Treatment of these mice with N2733 (100 mg/kg x 2, i.p.) decreased the serum level of TNF-alpha significantly. Another model was DBA/2 mice induced with LPS (30 mg/kg, i.v.), which reduced the survival rate to 30% during 7 days. Administrations of 30 mg/kg and 100 mg/kg N2733 (i.v.) restored the survival rates to 60% and 90% respectively. Our data demonstrate that N2733 inhibits LPS-induced TNF-alpha production, and this response is associated with an improvement in the survival rate of endotoxemic mice.     

Nimesulide prevents lipopolysaccharide-induced elevation in plasma tumor necrosis factor-alpha in rats

The present study was undertaken to test the hypothesis of possible inhibitory effect of nimesulide (4-nitro-2-phenoxymethane-sulfoxide) on plasma TNF-alpha level. Male Sprague-Dawley rats were injected intraperitoneally (i.p.) with E. coli lipopolysaccharide (LPS; 1 mg/kg), which resulted in a dramatic increase in plasma TNF-alpha level peaked 60 min post injection (3890+/-280 pg/ml, compared to undetectable values in the control group). Nimesulide (30 mg/kg) injected i.p. 60 min prior to LPS, prevented LPS-induced elevation in plasma TNF-alpha. Nimesulide alone did not alter circulating levels of TNF-alpha. It appears that the anti-inflammatory properties of nimesulide may in part be attributed to its inhibitory effect on TNF-alpha production.     

Extravasation of leukocytes assessed by intravital microscopy: effect of thalidomide

OBJECTIVE AND DESIGN: Thalidomide is very effective in the treatment of idiopathic aphthous stomatitis, characterized by recurrent focal intramucosal leukocytic vasculitis. The mode of action of thalidomide in this clinical entity may include inhibition of the extravasation of leukocytes. Therefore, we studied the effect of thalidomide on different steps of leukocyte migration by intravital microscopy. MATERIAL: Male Syrian golden hamsters were used. TREATMENT: Leukocyte migration in buccal mucosa of the hamster cheek pouch was elicited by the local application of lipopolysaccharide (LPS, 20 micrograms/ml) or murine tumor necrosis factor-alpha (muTNF-alpha, 10 ng/ml). (+)-Thalidomide (20-200 mg/kg i.p.) was administered 60 min before the local application of LPS or muTNF-alpha. Dexamethasone (2 x 1.0-10 mg/kg i.p.) was administered 18 h and 60 min before topical LPS application. METHODS: The numbers of rolling, firmly adherent and migrating leukocytes were estimated by intravital microscopy up to 165 min after the topical applications of LPS or muTNF-alpha and evaluated by an interactive image analysis software. RESULTS: Thalidomide (20-200 mg/kg i.p.) dose-dependently inhibited LPS-stimulated perivenular leukocyte migration by up to 87 +/- 5% and muTNF-alpha-induced leukocyte migration by up to 78 +/- 4%. Dexamethasone (2 x 1.0-10 mg/kg i.p.) inhibited LPS-stimulated leukocyte migration by up to 85 +/- 13%. (+)-Thalidomide (200 mg/kg i.p.) inhibited LPS-stimulated rolling by 80 +/- 5% and reduced the number of firmly adherent leukocytes by about 40%. Dexamethasone (2 x 10 mg/kg i.p.) did not reduce the number of rolling leukocytes but inhibited leukocyte adherence by 72 +/- 9%. CONCLUSIONS: These results show that (+)-thalidomide predominantly inhibits leukocyte rolling and thus differs from the glucocorticoid dexamethasone. The inhibition of LPS- or muTNF-alpha-induced leukocyte extravasation by thalidomide may account for some of its clinical activities.     

A two-term MEDLINE search strategy for identifying randomized trials in obstetrics and gynecology

In this study, we examined whether endothelin (ET) plays a role in the short-term increase in mean arterial pressure (MAP) after nitric oxide synthase (NOS) inhibition with N(omega)-nitro-L-arginine methyl ester (L-NAME) in stroke-prone spontaneously hypertensive rats (SHRSPs). Experiments were performed by using Inactin-anesthetized male SHRSPs that were pretreated with chlorisondamine to block reflex autonomic cardiovascular effects. Injection of L-NAME (10 mg/kg, i.v.), but not D-NAME, produced rapid and marked increases (74 +/- 3 mm Hg) in MAP that were sustained for >1 h. In SHRSPs that were treated with the ET(A/B) receptor antagonist, L-754,142 (15 mg/kg + 15 mg/kg/h), L-NAME increased MAP by 45 +/- 4 mm Hg (p < 0.0001 compared with L-NAME alone). L-754,142 blocked pressor responses to big ET-1 by >90% but was without effect on pressor responses to norepinephrine. Plasma levels of ET-1 averaged 5 +/- 1 pg/ml in animals given vehicle and were slightly increased in animals given either L-NAME alone (7 +/- 2 pg/ml) or L-754,142 alone (7 +/- 2 pg/ml) but increased markedly when L-NAME and L-754,142 were given together (114 +/- 18 pg/ml). This may relate to an effect of L-754,142 to block ET-receptor-mediated clearance of ET-1. We conclude that ET plays a role in the short-term pressor response after NOS inhibition in SHRSPs.     

Effect of matrine on mouse hepatitis and tumor necrosis factor production induced by Propionibacterium acnes/lipopolysaccharides

The effect of matrine (Mat) on lipopolysaccharides (LPS)-induced fatal hepatitis and tumor necrosis factor (TNF) production in Propionibacterium acnes (PA)-primed mice were studied. Mice were injected i.p. LPS (10 micrograms/mouse) 7 d after i.p. PA (0.5 ml/mouse) to induce fatal hepatitis. After i.p. LPS, serum TNF activity rose to 1657 +/- 406 kU.L-1 at 1.5 h and ALT activity increased up to 1,496 +/- 890 U.L-1 at 5 h. Six of 8 mice died within 5 h and the massive hemorrhagic necrosis of the liver was observed in all mice. Administration of Mat (10, 50 mg.kg-1, i.p., bid x 3 d) before the LPS injection markedly reduced the elevation of serum TNF and ALT activity in a dose-dependent manner, and diminished the mortality induced by LPS. Liver congestion and necrosis induced by LPS in PA-primed mice were ameliorated markedly by Mat pretreatment. Mat (62.5-250 mg.L-1) inhibited LPS-induced TNF release from PA-primed mouse peritoneal macrophage in vitro in a concentration-dependent manner. These results seggest that Mat protected PA-primed mice from the development of fatal hepatitis induced by LPS due to inhibition of TNF production.     

Pentoxifylline attenuates neutrophil activation in experimental endotoxemia in chimpanzees

Costimulation of neutrophils and cytokines may play an important role in organ injury in sepsis. Pentoxifylline inhibits various neutrophil functions in vitro, and attenuates endotoxin-induced production of TNF in both in vitro and in vivo models. To assess the effect of pentoxifylline on neutrophil activation in endotoxemia, nine adult chimpanzees (Pan troglodytes) were i.v. injected with saline (n = 2), Escherichia coli endotoxin (4 ng/kg; n = 4), or E. coli endotoxin (4 ng/kg) in combination with pentoxifylline (500 mg/3 h, starting 30 min before the endotoxin injection; n = 3). Serial blood samples were obtained for measurements of leukocyte counts and the granulocytic proteinases elastase complexed with alpha 1-antitrypsin and lactoferrin, and cytokines during the next 5 h. No changes were observed in the saline-treated chimpanzees. Endotoxin induced a marked leukocytosis and neutrophilia, which were slightly reduced by pentoxifylline. In contrast, pentoxifylline almost completely prevented endotoxin-induced neutrophil degranulation: peak elastase-alpha 1-antitrypsin was 164 +/- 21 ng/ml (mean +/- SE) after endotoxin alone, vs 71 +/- 7 ng/ml after endotoxin with pentoxifylline (t = 3 h; p < 0.05); peak lactoferrin was 329 +/- 15 and 182 +/- 5 ng/ml, respectively (t = 5 h; p < 0.05). Pentoxifylline also inhibited the endotoxin-induced release of TNF (271 +/- 26 vs 55 +/- 23 pg/ml at t = 1.5 h; p < 0.05) and IL-6 (225 +/- 42 vs 73 +/- 25 pg/ml at t = 2 h; p < 0.05). IL-8 release was not significantly inhibited by pentoxifylline. In none of the animals activation of the C system could be detected. We conclude that pentoxifylline attenuates neutrophil activation in endotoxemia in chimpanzees, probably in part by inhibiting the release of TNF.     

Denopamine, a beta1-adrenergic agonist, prolongs survival in a murine model of congestive heart failure induced by viral myocarditis: suppression of tumor necrosis factor-alpha production in the heart

OBJECTIVES: This study was designed to examine the effects of denopamine, a selective beta1-adrenergic agonist, in a murine model of congestive heart failure (CHF) due to viral myocarditis. BACKGROUND: Positive inotropic agents are used to treat severe heart failure due to myocarditis. However, sympathomimetic agents have not been found beneficial in animal models of myocarditis. METHODS: In vitro: The effects of denopamine on lipopolysaccharide-induced tumor necrosis factor-alpha (TNF-alpha) production was studied in murine spleen cells. In vivo: Four-week-old DBA/2 mice were inoculated with the encephalomyocarditis virus (day 0). Denopamine (14 micromol/kg), denopamine (14 micromol/kg) with a selective beta1-blocker metoprolol (42 micromol/kg), or denopamine (14 micromol/kg) with metoprolol (84 micromol/kg) was given daily, and control mice received the vehicle only. Survival and myocardial histology on day 14 and TNF-alpha levels in the heart on day 6 were examined. RESULTS: In the in vitro study, TNF-alpha levels in treated cells were significantly lower than in controls (p < 0.05). In the in vivo study treatment with denopamine significantly improved the survival of the animals (14 of 25 (56%) treated, vs 5 of 25 (20%) control mice), attenuated myocardial lesions, and suppressed TNF-alpha production (66.5+/-7.5 pg/mg of heart in treated mice vs 113.5+/-15.1 pg/mg of heart in control mice, mean+/-SE). There was a strong linear relationship between mortality and TNF-alpha levels (r=0.98, n=4, p < 0.05). These in vitro and in vivo effects of denopamine were significantly inhibited by metoprolol. CONCLUSIONS: These results suggest that denopamine may exert its beneficial effects, in part, by suppressing the production of TNF-alpha via beta1-adrenoceptors.     

Nitric oxide inhibits LPS-induced tumor necrosis factor synthesis in vitro and in vivo

The effect of nitric oxide (NO) on LPS-stimulated TNF-alpha synthesis has been studied in vitro and in vivo. The synthesis of TNF-alpha in J774 macrophages stimulated with LPS (0.1 microgram/ml) was increased in concentration-related fashion by NO synthase inhibitor L-NMMA (3-30-300 microM) and reduced by either L-arginine (3-30-300 microM) or the NO donor SIN-1 (1-10-100 microM). The level of TNF-alpha in the serum of LPS-challenged rats (6mg/kg/i.p.) was increased in animals pre-treated s.c. with L-NMMA (10 and 50mg/kg) and reduced in those given L-arginine (100 and 300mg/kg). These results show a negative feedback mechanism exhibited by NO on TNF-alpha synthesis suggesting an important regulatory link between NO and TNF-alpha in pathological processes.     

The in vivo pharmacological profile of the novel glycoprotein IIb/IIIa antagonist, SK&F 106760

The in vivo pharmacological profile of SK&F 106760 [N alpha-acetyl-cyclo(S,S)-cysteinyl-N alpha-methylarginyl-glycyl-aspartyl-penicillamine-amide], a novel, potent glycoprotein IIb/IIIa (GPIIb/IIIa) antagonist has been investigated. In conscious dogs, SK&F 106760 (0.3-3 mg/kg i.v.) produced a dose-related inhibition of ex vivo whole blood platelet aggregation induced by collagen (5 micrograms/ml) with complete inhibition being produced for 5, 90 and 165 min after administration of 0.3, 1 and 3 mg/kg i.v., respectively. Plasma levels of SK&F 106760 were measured by high-performance liquid chromatography after i.v. bolus administration of 1 mg/kg. An initial alpha-disposition phase with a T1/2 of 11 +/- 6 min was followed by a longer terminal beta-elimination phase with a T1/2 of 66 +/- 12 min, which accounted for 79 +/- 9% of the total area under the plasma concentration-time curve. The apparent steady-state volume of distribution was 259 +/- 26 ml/kg and the plasma clearance was 3.4 +/- 0.8 ml/min/kg. The plasma concentration of SK&F 106760 at which collagen-induced ex vivo whole blood aggregation was inhibited by 50% was estimated to be 593 +/- 52 nM. After intraduodenal and intrajejunal administration of 3 mg/kg, SK&F 106760 had a bioavailability of 3 to 6% and produced a peak inhibition of ex vivo platelet aggregation of 40 to 50%. In anesthetized dogs, SK&F 106760 (0.3-3.0 mg/kg i.v.) produced a complete inhibition of platelet-dependent coronary artery thrombosis, with a dose-related duration of action.(ABSTRACT TRUNCATED AT 250 WORDS)     

Calcitriol modulates in vivo and in vitro cytokine production: a role for intracellular calcium

Calcitriol modulates in vivoand in vitro cytokine production: A role for intracellular calcium. Background. Several immunomodulatory properties of calcitriol are currently known, however, only little information is available regarding the in vivo and in vitro effects of calcitriol on cytokine production in chronic renal failure. Methods. To study the in vitro effect of calcitriol on lipopolysaccharide (LPS)-induced cytokine production, peripheral blood mononuclear cells (PBMC, 2.5 ml/ml) from 12 chronic dialytic (HD), 15 undialyzed chronic renal failure (CRF) patients and 10 normal subjects (N) were incubated at 37 degrees for 12 hours with 100 ng of LPS (E. coli and P. maltofilia). Increasing doses of calcitriol from 10-10 to 10-9 M were added and cell associated TNF-alpha and IL-1beta were determined by immunoreactive tests after three freeze-thaw cycles. The intradialytic TNF-alpha and IL-1beta production were evaluated in vivo in 12 HD patients before and after three months of intravenous calcitriol treatment (6 microgram/week). Intracellular calcium [Ca++]i was determined on PBMC with a cytofluorimetric assay using FLUO-3 AM as the indicator. Results. In vitro, TNF-alpha increased from 3.6 +/- 1.9 pg/cell to 1797 +/- 337 in N, from 4.5 +/- 1.7 to 1724 +/- 232 in CRF and from 3.4 +/- 2.3 to 1244 +/- 553 in HD after the LPS stimulus. The production of TNF-alpha was inhibited by calcitriol in a dose-dependent manner [LPS + Vit.D3 100 ng, 2.9 +/- 2.1 in N, 3.7 +/- 1.9 in CRF and 3.4 +/- 1.7 in HD; LPS + Vit.D3 50 ng, 263 +/- 296 (N), 6.73 +/- 11 (CRF), 38 +/- 28 (HD); LPS + Vit.D3 25 ng = 873 +/- 583 (N), 325 +/- 483 (CRF), 588 +/- 507 (HD); LPS + Vit.D3 12.5 ng, 954 +/- 483 (N), 912 +/- 510 (CRF), 875 +/- 527 (HD)]. Comparable data were observed on IL-1beta production. In vivo, the intradialytic TNF-alpha increase (from 8.5 +/- 2.3 to 19 +/- 5.6 pg/2.5 x 106 cell) during hemodialysis was markedly reduced after calcitriol therapy (from 6.6 +/- 3.1 to 11 +/- 4.7). [Ca++]i decreased from 105 +/- 25 to 72 +/- 18 nM (P < 0.05) and a positive correlation between cytokine levels and [Ca++]i was found (r = 0.79; P < 0.001). Conclusions. The in vitro increase of cell-associated cytokine after LPS challenge was inhibited by calcitriol in a dose-dependent manner. These data suggest a possible in vivo modulatory effect of calcitriol therapy on cytokine production in hemodialysis.     

Synchrony in telomere length of the human fetus

We measured serum tumour necrosis factor-alpha (TNF-alpha) as well as interleukin-1betta (IL-1beta) and GH concentrations in 15 children with isolated growth hormone deficiency (GHD), age range 5.1-13.9 years, before and 4 and 24h after the first GH injection (0.1 IU/kg s.c.). No differences were found in basal concentrations of serum TNF-alpha and IL-1beta between GHD children (10.01 +/- 1.55 pg/ml and 2.14 +/- .16 ng/ml respectively) and sex- and age-matched controls (11.57 +/- 2.16 pg/ml and 3.78 +/- 1.46 ng/ml respectively). In GHD children, serum TNF-alpha and IL-1beta values had significantly increased (P < 0.002) 4h (26.75 +/- 5.57 pg/ml and 2.99 +/- 0.21 ng/ml respectively) and decreased again 24 h after GH administration. Likewise, serum GH levels had significantly increased 4 h (from 1.29 +/- 0.69 to 48.71 +/- 13.35 ng/ml, P < 0.001) and decreased to basal values 24h after GH administration. A significant correlation was found between basal serum concentrations of GH and those of both TNF-alpha (P < 0.01) and IL-1beta (P < 0.05). However, no correlation was found between serum GH concentration and either TNF-alpha or IL-1beta levels 4 and 24h after GH administration. Our data suggest that GH plays a role in modulating TNF-alpha and IL-1beta release in humans.     

Selective inhibition of cyclooxygenase-2 by NS-398 in endotoxin shock rats in vivo

OBJECTIVE AND DESIGN: The role of cyclooxygenase (COX)-2 was examined using a rat endotoxin shock model and the potency and selectivity of NS-398, a COX-2 selective inhibitor in vitro, for COX-2 activity was examined in vivo. MATERIAL: Male Wistar rats (weighing 140-180 g) were used. METHODS: Lipopolysaccharide (LPS, 1 mg/kg, i.v.) was administered to rats (LPS-treated rats) and expression of COX-1 mRNA and COX-2 mRNA in the aorta and peripheral blood leukocytes was examined by RT-PCR. COX activity was assessed by measuring the plasma 6-keto prostaglandin (PG) F1 alpha, PGE2 and thromboxane (TX)B2 30s after administration of arachidonic acid (AA, 3 mg/kg, i.v.), NS-398 (0.3-100 mg/kg, p.o.) or indomethacin (0.3-3 mg/kg, p.o.) was administered 1 h before the AA injection. RESULTS: COX-2 mRNA was detectable in the aorta and peripheral blood leukocytes at least from 3 to 9 h after the LPS injection but not in non-LPS-treated rats. Plasma 6-keto PGF1 alpha, PGE2 and TXB2 levels after AA injection into LPS-treated rats were significantly enhanced compared to findings in non-LPS-treated rats. NS-398 showed significant inhibition of the increase in PGs in LPS-treated rats, the ED50 values being 0.35 mg/kg for 6-keto PGF1 alpha, 1.5 mg/kg for PGE2 and < 0.3 mg/kg for TXB2. NS-398 even at 100 mg/kg did not significantly suppress the increased PGs levels in non-LPS-treated rats. In contrast, indomethacin significantly inhibited plasma PGs levels after AA injection into LPS-treated rats and non-LPS-treated rats. The ED50 values in LPS-treated rats, determined by 6-keto PGF1 alpha, PGE2 and TXB2 production, were 1.0, 1.3 and 2.3 mg/kg and those in non-LPS-treated rats were 0.42, 0.24 and 0.93 mg/kg, respectively. CONCLUSIONS: In a rat endotoxin shock model, expression of COX-2 plays a role in an increase in COX activity. NS-398 showed preferential inhibitory effects on COX-2 activity in vivo. This approach is useful to directly analyze the inhibitory activity of NSAIDs for COX-1 and COX-2 in vivo.     

Pharmacological analysis of the heterogeneous discriminative stimulus effects of ethanol in rats using a three-choice ethanol-dizocilpine-water discrimination

The present study used a three-choice operant drug discrimination procedure to determine if NMDA-mediated discriminative stimulus effects could be separated from other stimulus effects of 2.0 g/kg ethanol. Adult male Long-Evans rats (n = 7) were trained to discriminate dizocilpine (0.17 mg/kg; i.g.) from ethanol (2.0 g/kg; i.g.) from water (4.7 ml; i.g.) using food reinforcement. Substitution tests were conducted following administration of the GABA(A) positive modulators allopregnanolone (5.6-30.0 mg/kg; i.p.), diazepam (0.3-10.0 mg/kg; i.p.) and pentobarbital (1.0-21.0 mg/kg; i.p.), the non-competitive NMDA antagonist phencyclidine (0.3-10.0 mg/kg; i.p.), the 5-HT1 agonists TFMPP (0.3-5.6 mg/kg; i.p.) and RU 24969 (0.3-3.0 mg/kg; i.p.), and isopropanol (0.10-1.25 g/kg; i.p.). Allopregnanolone, diazepam and pentobarbital substituted completely (>80%) for ethanol. Isopropanol partially (77%) substituted for ethanol. Phencyclidine substituted completely for dizocilpine. RU 24969 and TFMPP did not completely substitute for either training drug, although RU 24969 partially (62%) substituted for ethanol. Successful training of this three-choice discrimination indicates that the discriminative stimulus effects of 0.17 mg/kg dizocilpine were separable from those of 2.0 g/kg ethanol. The finding that attenuation of NMDA-mediated effects of ethanol occurred without altering significantly GABA(A)- and 5-HT1-mediated effects suggests that the NMDA component may be independent of other discriminative stimulus effects of 2.0 g/kg ethanol.     

Preventive effect of ritodrine hydrochloride and/or urinary trypsin inhibitor against lipopolysaccharide-induced preterm delivery in mice

BACKGROUND: The purpose of this study was to confirm the preventive effect of ritodrine hydrochloride (ritodrine) alone or ritodrine plus urinary trypsin inhibitor (UTI) in a mouse model of preterm delivery. METHODS: On day 17 of pregnancy, female C3H/HeN mice impregnated by male B6D2F1 mice were given two intraperitoneal injections of lipopolysaccharide (LPS) (50 micrograms/kg) at a 3-hour interval, which induced a 100% incidence of preterm delivery within 25 hours of the second dose. Ritodrine (1, 3, or 10 mg/kg, p.o.), UTI (25 X 10(4) units/kg, i.p.), ritodrine (3 mg/kg, p.o.) plus UTI (25 x 10(4) units/kg, i.p.), distilled water (10 ml/kg, p.o.), or distilled water (10 mg/kg, p.o.) plus saline solution (10 ml/kg, i.p.) were administered to the pregnant animals 10 times at 1-hour intervals from 8:00 AM to 5:00 PM on day 18 of pregnancy. In addition, the preventive effect of ritodrine, UTI, or ritodrine plus UTI was examined on LPS-induced contraction of uterine muscle strips isolated from pregnant mice on day 17 of gestation. RESULTS: The incidence of preterm delivery decreased significantly in a dose-dependent fashion with ritodrine treatment, and there was a significant and synergistic decrease after combined treatment with ritodrine plus UTI. The in vitro uterine contraction induced by LPS was significantly suppressed by both ritodrine and UTI. CONCLUSIONS: Combination therapy with ritodrine plus UTI may be helpful for preventing preterm delivery in humans without the cardiovascular side effects that often accompany treatment with ritodrine alone.     

Inhibition of tumor necrosis factor and subsequent endotoxin shock by pirfenidone

Tumor necrosis factor-alpha (TNF) is an extremely potent cytokine which is involved in the pathogenesis of a number of diseases. Interruption of its synthesis can result in a reduction of inflammation and subsequent pathology. A new experimental drug pirfenidone (5-methyl-L-phenyl-2-(1H)-pyridone, trade name: Deskar) has been reported to have beneficial effects for the treatment of certain fibrotic diseases. The present study describes the inhibition of TNF in vitro as well as the inhibition of circulating TNF in vivo by pirfenidone. Isolated, thioglycollate-induced peritoneal macrophages (Mphi) from C57BL/6 mice were exposed to either lipopolysaccharide (LPS) or mannosylated bovine serum albumin then incubated with 0.1-0.9 mg/ml of pirfenidone. This substance inhibited the production of TNF in a dose-dependent manner as measured by ELISA. One i.p. injection of either 100 or 200 mg/kg pirfenidone inhibited the induction of circulating TNF following a single i.v. injection of LPS. Endotoxin shock was induced in mice using an i.p. injection of galactosamine and LPS. The higher dose of pirfenidone (200 mg/kg) completely inhibited shock and subsequent mortality. Lower doses of pirfenidone or administration either prior to or post challenge only partially inhibited symptoms. These results indicate that pirfenidone is able to inhibit both TNF induction and subsequent endotoxin shock. Additional studies are warranted to establish this drug as a potential treatment for diseases where TNF plays a major role.     

Relationship between nitric oxide and platelet-activating factor in castor-oil induced mucosal injury in the rat duodenum

The modulation of platelet activating factor (PAF) formation in duodenal tissue by nitric oxide (NO) released in response to castor oil was studied in rats pretreated with NG-nitro-L-arginine methyl ester (L-NAME, 6.25-25 mg/kg, i.p.), an inhibitor of NO synthase, NG-nitro-D-arginine methyl ester (D-NAME, 25 mg/kg, i.p.), the inactive enantiomer of L-NAME or isosorbide-5-mononitrate (IMN, 30-90 mg/kg, p.o.), a NO donating compound. Castor oil (2 ml/rat orally) increased PAF production in the rat duodenum 3 h after challenge. L-NAME, but not D-NAME, enhanced the amount of PAF formed by duodenal tissue, while IMN (30-90 mg/kg) counteracted the effects of L-NAME (12.5 mg/kg) and also reduced PAF release in the tissue of rats treated with castor oil. L-NAME 12.5 mg/kg, but not D-NAME, enhanced both macroscopic damage and acid phosphatase release induced by castor oil. These effects were reduced by a PAF antagonist BN 52021 (3-t-Butyl-hexahydro-4, 7b, 11-trihydroxy-8-methyl-9H-1, 7a-epoxymethano-1H, 6aH-cyclopenta [c] furo [2, 3b] furo [3'2':3,4] cyclopenta [1.2-d]furan-5,9,12(4H)trione) 10 and 20 mg/kg i.p. Such findings suggest that endogenous nitric oxide could reduce PAF biosynthesis in castor oil-treated rats.     

In vivo functional interaction between phencyclidine binding sites and sigma receptors to produce head-weaving behavior in rats

To investigate the in vivo functional interaction between phencyclidine (1-(1-phenylcyclohexyl)piperidine; PCP) binding sites and sigma receptors, we examined the effects of sigma receptor ligands on stereotyped head-weaving behavior induced by PCP, a putative PCP/sigma receptor ligand, and (+)-5-methyl-10,11-dihydroxy-5H-dibenzo(a,d)cyclo-hepten-5,10-imin e ((+)-MK-801; dizocilpine), a selective PCP binding site ligand, in rats. PCP (7.5 mg/kg, i.p.)-induced head-weaving behavior was inhibited by both N,N-dipropyl-2-[4-methoxy-3-(2-phenylethoxy)-phenyl]-ethylamine (NE-100; 0.03-1.0 mg/kg, p.o.), a selective sigma1 receptor ligand, and alpha-(4-fluorophenyl)-4-(5-fluoro-2-pyrimidinyl)-1-piperidine butanol (BMY-14802; 3 and 10 mg/kg, p.o.), a prototype sigma receptor ligand, in a dose-dependent manner, whereas NE-100 (0.1-1.0 mg/kg, p.o.) and BMY-14802 (3 and 10 mg/kg, p.o.) did not inhibit dizocilpine (0.25 mg/kg, s.c.)-induced head-weaving behavior. These results suggest that NE-100 and BMY-14802 act via sigma receptors. Dizocilpine-induced head-weaving behavior was potentiated by 1,3-di-o-tolyl-guanidine (DTG; 0.03-0.3 microg/kg, i.v.) and (+)-3-(3-hydroxyphenyl)-N-(1-propyl)piperidine ((+)-3-PPP; 3 and 6 mg/kg, i.p.), sigma1/sigma2 receptor ligands, as well as by (+)-N-allyl-normetazocine ((+)-SKF-10,047: 8 mg/kg, i.p.), a sigma1 receptor ligand, while DTG (0.3 microg/kg, i.v.), (+)-3-PPP (6 mg/kg, i.p.) and (+)-SKF-10,047 (8 mg/kg, i.p.) did not induce this behavior. Potentiation of dizocilpine-induced head-weaving behavior by DTG (0.3 microg/kg, i.v.), (+)-3-PPP (6 mg/kg, i.p.) and (+)-SKF-10,047 (8 mg/kg, i.p.) was completely blocked by NE-100 (0.1 mg/kg, p.o.) and BMY-14802 (10 mg/kg, p.o.). These results suggest that PCP binding sites and sigma receptors are involved in PCP-induced head weaving behavior, and that sigma1 receptors play an important role in modulation of the head-weaving behavior.     

Minor physical anomalies in schizophrenia and mood disorders

The purpose of the present study was to examine the effect of a two day and a five day administration of 22-oxa-calcitriol (OCT) on calcium metabolism in rats with advanced chronic renal failure and severe secondary hyperparathyroidism. A first series of 27 uremic rats received either placebo, OCT or calcitriol (0.3 microgram i.p./rat) 48 and 24 hours before sacrifice. A second series of 18 uremic rats received either placebo, OCT (0.3 microgram i.p./rat) or calcitriol (0.05 microgram i.p./rat) for five days. We found that after 48 hours (series 1) both calcitriol and OCT increased blood ionized calcium (Ca2+) as compared to vehicle (1.23 +/- 0.04 and 1.10 +/- 0.02 mM, P < 0.01 and P < 0.05, respectively vs. control, 1.02 +/- 0.03 mM). Duodenal Ca transport (S/M) using the everted gut sac technique was not stimulated by OCT, even though it increased from 2.8 +/- 0.4 to 7.0 +/- 0.6 (P < 0.01) with calcitriol. In contrast, duodenal calbindin-D9k mRNA expression and protein content increased to a similar extent with OCT and calcitriol. Calcitriol was more potent in reducing plasma iPTH1-34 levels than OCT: 344 +/- 75 pg/ml (calcitriol) versus 632 +/- 46 pg/ml (OCT) compared with 897 +/- 74 pg/ml (control), P < 0.01. In the second series of rats, the injection of OCT (0.3 microgram i.p./rat) over five days was less effective than the lower dose of calcitriol (0.05 microgram i.p./rat) in reducing circulating iPTH: 110 +/- 26 (calcitriol) and 281 +/- 64 (OCT) versus 624 +/- 135 pg/ml (control), P < 0.01.(ABSTRACT TRUNCATED AT 250 WORDS)