Showing papers by "Achille P. Caputi published in 2004"

Adrenocorticotropin reverses hemorrhagic shock in anesthetized rats through the rapid activation of a vagal anti-inflammatory pathway.

Abstract: Objective : Several melanocortin peptides have a prompt and sustained resuscitating effect in conditions of hemorrhagic shock. The transcription nuclear factor kB (NF-kB) triggers a potentially lethal systemic inflammatory response, with marked production of tumor necrosis factor-α (TNF-α), in hemorrhagic shock. Here we investigated whether the hemorrhagic shock reversal produced by the melanocortin ACTH-(1–24) (adrenocorticotropin) depends on the activation of the recently recognized, vagus nerve-mediated, brain “cholinergic anti-inflammatory pathway”. Methods and results : Anesthetized rats were stepwise bled until mean arterial pressure (MAP) atabilized at 20–25 mm Hg. The severe hypovolemia was incompatible with survival, and all saline-treated animals died within 30 min. In rats intravenously (i.v.) treated with ACTH-(1–24), neural efferent activity along vagus nerve (monitored by means of a standard system for extracellular recordings) was markedly increased, and the restoration of cardiovascular and respiratory functions was associated with blunted NF-kB activity and with decreased TNF-α mRNA liver content and TNF-α plasma levels. Bilateral cervical vagotomy, pretreatment with the melanocortin MC4 receptor antagonist HS014, atropine sulfate or chlorisondamine, but not with atropine methylbromide, prevented the life-saving effect of ACTH-(1–24) and the associated effects on NF-kB activity and TNF-α levels. HS014 and atropine sulfate prevented, too, the ACTH-(1–24)-induced increase in neural efferent vagal activity, and accelerated the evolution of shock in saline-treated rats. Conclusions : The present data show, for the first time, that the melanocortin ACTH-(1–24) suppresses the NF-kB-dependent systemic inflammatory response triggered by hemorrhage, and reverses shock condition, by brain activation (in real-time) of the “cholinergic anti-inflammatory pathway”, this pathway seeming to be melanocortin-dependent.

Superoxide: a key player in hypertension

Abstract: Superoxide is increased in the vessel wall of spontaneously hypertensive rats (SHR) where, if “blocked,” potentiates endothelium-dependent vasodilation. The purpose of this study was to determine the role of superoxide anion in hypertension and its interaction with nitric oxide (NO). For this purpose we used a low molecular weight synthetic superoxide dismutase mimetic (M40403), known to remove selectively superoxide anion. Baseline mean arterial pressure (MAP) was significantly elevated in the SHR compared with its normal counterpart, Wistar Kyoto (WKY). M40403 at a dose (2 mg·kg–1·h–1), which had no effect in the WKY, significantly decreased MAP in SHR rats. To determine whether superoxide anion increases MAP by inactivating NO, NO synthesis was blocked with NG nitro-arginine methyl ester (L-NAME, 3 mg/kg i.v.), a nonselective nitric oxide synthase inhibitor. L-NAME (3 mg/kg, i.v) blocked the anti-hypertensive effect of M40403 (2 mg/kg over 30 min). When used at a dose that yielded similar increases in ...

Rosiglitazone, a ligand of the peroxisome proliferator-activated receptor-gamma, reduces acute pancreatitis induced by cerulein

Abstract: In the present study, we investigated the effects of rosiglitazone (10 mg/kg, i.p.), a PPAR-γ agonist, on the development of acute pancreatitis. Intraperitoneal injection of cerulein in mice induced an acute pancreatitis characterized by edema, neutrophil infiltration elevated serum levels of amylase and lipase. This experimental model was performed to test the anti-inflammatory activity of rosiglitazone. University research laboratory. Male CD mice (20–22 g) were allocated into four groups (n=10 for each group): (a) Cerulein+vehicle group. Mice were treated hourly (×5) with cerulein (50 μg/kg, in saline solution, i.p.); (b) Rosiglitazone group (same as the Cerulein+vehicle group but were administered rosiglitazone, 10 mg/kg bolus, 30 min prior to cerulein); (c) Sham+saline group. Mice were treated with saline instead of cerulein; (d) Sham+Rosiglitazone. Identical to Rosiglitazone group except that the saline was administered instead of cerulein. Mice were killed at 6 h after the induction of pancreatitis. Blood samples, pancreas, and lungs were collected. Infiltration of pancreatic and lung tissue with neutrophils was associated with enhanced lipid peroxidation. Immunohistochemical examination demonstrated a marked increase in immunoreactivity for nitrotyrosine and for ICAM-1 in the pancreas of cerulein-treated mice. In contrast, the degree of (a) pancreatic inflammation and tissue injury, (b) upregulation/formation of ICAM-1 and nitrotyrosine, and (c) neutrophils infiltration was markedly reduced in pancreatic tissue obtained from rosiglitazone-treated mice. These findings support the view that rosiglitazone and other potent PPAR-γ agonists may be useful in the therapy of acute pancreatitis.

Treatment with a novel poly(ADP-ribose) glycohydrolase inhibitor reduces development of septic shock-like syndrome induced by zymosan in mice.

Abstract: Objective:Poly(ADP-ribose) is synthesized from nicotinamide adenine dinucleotide by poly(ADP-ribose) polymerase (PARP) and degraded by poly(ADP-ribose) glycohydrolase (PARG). The activation of the PARP/PARG pathway has been found in a variety of animal models of diseases, including septic shock-like

Rosiglitazone, a ligand of the peroxisome proliferator-activated receptor-gamma, reduces the development of nonseptic shock induced by zymosan in mice.

Abstract: Objective Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of ligand-activated transcription factors that are related to retinoid, steroid, and thyroid hormone receptors. The PPAR-gamma receptor subtype appears to play a pivotal role in the regulation of cellular proliferation and inflammation. Rosiglitazone (Avandia) is a PPAR-gamma agonist (the most potent PPAR-gamma agonist of the thiazolidinedione antidiabetics). In the present study, we investigated the effects of rosiglitazone on the development of nonseptic shock caused by zymosan in mice. Design Experimental study. Setting University laboratory. Subjects Male CD mice. Interventions We investigated the effects of rosiglitazone (3 mg/kg) on the development of nonseptic shock caused by zymosan (500 mg/kg, administered intraperitoneally as a suspension in saline) in mice. Measurements and main results Organ failure and systemic inflammation in rats were assessed 18 hrs after administration of zymosan and/or rosiglitazone and monitored for 12 days (for loss of body weight and mortality rate). Treatment of mice with rosiglitazone (3 mg/kg intraperitoneally, 1 and 6 hrs after zymosan) attenuated the peritoneal exudation and the migration of polymorphonuclear cells caused by zymosan. Rosiglitazone also attenuated the lung, liver, and pancreatic injury and renal dysfunction caused by zymosan as well as the increase in myeloperoxidase activity and malondialdehyde concentrations caused by zymosan in the lung and intestine. Immunohistochemical analysis for inducible nitric oxide synthase, nitrotyrosine, and poly(adenosine diphosphate-ribose) revealed positive staining in lung and intestine tissues obtained from zymosan-treated mice. The degree of staining for nitrotyrosine, inducible nitric oxide synthase, and poly(adenosine diphosphate-ribose) was markedly reduced in tissue sections obtained from zymosan-treated mice that received rosiglitazone. To elucidate whether the protective effects of rosiglitazone are related to activation of the PPAR-gamma receptor, we also investigated the effect of a PPAR-gamma antagonist, GW 9662, on the protective effects of rosiglitazone. GW 9662 (1 mg/kg administered intraperitoneally 30 mins before treatment with rosiglitazone) significantly antagonized the effect of the PPAR-gamma agonist and thus abolished the protective effect. Conclusions This study provides evidence, for the first time, that rosiglitazone attenuates the degree of zymosan-induced nonseptic shock in mice.

Effects of GW274150, a novel and selective inhibitor of iNOS activity, in acute lung inflammation

Abstract: The aim of this study was to investigate the effect of GW274150, a novel, potent and selective inhibitor of inducible nitric oxide synthase (iNOS) activity in a model of lung injury induced by carrageenan administration in the rats. Injection of carrageenan into the pleural cavity of rats elicited an acute inflammatory response characterized by: fluid accumulation in the pleural cavity which contained a large number of polymorphonuclear cells (PMNs) as well as an infiltration of PMNs in lung tissues and subsequent lipid peroxidation, and increased production of nitrite/nitrate (NOx), tumour necrosis factor α (TNF-α) and interleukin-1β (IL-1β). All parameters of inflammation were attenuated in a dose-dependent manner by GW274150 (2.5, 5 and 10 mg kg−1 injected i.p. 5 min before carrageenan). Carrageenan induced an upregulation of the intracellular adhesion molecules-1 (ICAM-1), as well as nitrotyrosine and poly (ADP-ribose) (PAR) as determined by immunohistochemical analysis of lung tissues. The degree of staining for the ICAM-1, nitrotyrosine and PAR was reduced by GW274150. These results clearly confirm that NO from iNOS plays a role in the development of the inflammatory response by altering key components of the inflammatory cascade. GW274150 may offer a novel therapeutic approach for the management of various inflammatory diseases where NO and related radicals have been postulated to play a role. British Journal of Pharmacology (2004) 141, 979–987. doi:10.1038/sj.bjp.0705683

Tempol reduces the activation of nuclear factor-kappaB in acute inflammation.

Abstract: Recent studies have demonstrated that Tempol, a membrane-permeable radical scavenger, exerts protective effects in various models of inflammation and shock. Since nuclear factor-kappaB (NF-kappaB) is a transcription factor, which plays a pivotal role in the induction of genes involved in physiological processes as well as in the response to inflammation, we have investigated the effect of Tempol on NF-kappaB activation in a model of acute inflammation in mice. Injection of carrageenan into the pleural cavity of mice induced an acute inflammatory response characterized by fluid accumulation in the pleural cavity, which contained a large number of neutrophils, as well as an increased production of tumor necrosis factor-alpha, (TNF-alpha) and interleukin-1alpha (IL-1alpha). Tempol (100mg/kg i.p 30min prior to carrageenan administration) significantly attenuated the degree of pleuritis caused by carageeenan (all parameters measured). Administration of carageeenan into the chest cavity (pleuritis) was associated with the activation of NF-kappaB in the lung. In particular, the appearance of IkappaB-alpha in homogenates of lung tissue was investigated by immunoblot analysis at 4h after carrageenan administration. IkappaB-alpha levels were substantially reduced in the lung tissue from carrageenan-treated mice in comparison with sham-treated mice. Furthermore, to detect any effects of Tempol on NF-kappaB/DNA binding, lung extracts were analyzed by EMSA. The DNA binding activity significantly increased in extracts obtained from lungs of vehicle-treated mice at 4h after carrageenan administration. Treatment of mice with Tempol caused a significant inhibition of carrageenan-induced IkappaB-alpha degradation and NF-kappaB/DNA binding activity. These data confirm that Tempol exerts potent anti-inflammatory properties and clearly demonstrates for the first time that Tempol reduces the activation of NF-kappaB in vivo.

Effect of anthocyanins contained in a blackberry extract on the circulatory failure and multiple organ dysfunction caused by endotoxin in the rat.

Abstract: Anthocyanins are a group of naturally occurring phenolic compounds related to the colouring of plants, flowers and fruits. These pigments are important as quality indicators, chemotaxonomic markers and for their antioxidant activities. Here we have investigated the therapeutic efficacy of anthocyanins contained in a blackberry extract on (i) circulatory failure, (ii), multiple organ dysfunction and (iii) activity of the inducible isoforms of nitric oxide (NO) synthase (iNOS) and cyclooxygenase (COX-2) in anaesthetised rats with endotoxic shock. In a model of endotoxic shock induced by lipopolysaccharide (LPS, E. coli, 10 mg/kg, i.v.) in the rat, pretreatment with anthocyanins present in the blackberry extract (5 mg/kg, i. v. 30 min before LPS) prevented the hypotension induced by LPS. Endotoxaemia also caused rises in the serum levels of (i) glutamyl oxaloacetic transaminase (GOT), glutamyl pyruvic transaminase (GPT), alkaline phosphates and bilirubin (hepatic dysfunction) (ii) creatinine (renal dysfunction), (iii) amylase and lipase (pancreatic injury), (iii) NOx and 6-keto-PGF1 alpha. Anthocyanins attenuated the hepatic and pancreatic injury, the renal dysfunction and decreased NOx and 6-keto-PGF1 alpha levels. Endotoxaemia for 6 h resulted in a substantial increase in iNOS and COX activity in rat lung, which was attenuated in rats pretreated with anthocyanins. Moreover, anthocyanins (0.02 - 0.32 mg/mL) inhibited in vitro iNOS and COX activity from lung of LPS-treated rats. Polymorphonuclear (PMN) infiltration (myeloperoxidase activity), lipid peroxidation (malondialdehyde levels), as well as tissue injury (histological examination) induced by LPS in rat lung and ileum was reduced by anthocyanins (5 mg/kg, i. v. 30 min before LPS). Furthermore, endotoxaemia induced the formation of nitrotyrosine and poly(ADP-ribose) synthetase (PARS) activation as determined by immunohistochemical analysis of lung and ileum tissues. The degree of staining was lowered by anthocyanin treatment. These results indicate that the anthocyanins contained in the blackberry extract exert multiple protective effects in endotoxic shock.

Glucocorticoid-induced TNF receptor family gene (GITR) knockout mice exhibit a resistance to splanchnic artery occlusion (SAO) shock.

Abstract: In the present study, we used glucocorticoid-induced tumor necrosis factor (TNF) receptor family gene knockout (GITR-KO) mice to evaluate a possible role of GITR on the pathogenesis of splanchnic artery occlusion (SAO) shock, which was induced in mice by clamping the superior mesenteric artery and the celiac artery for 30 min, followed thereafter by release of the clamp (reperfusion). At 60 min after reperfusion, animals were killed for histological examination and biochemical studies. There was a marked increase in the lipid peroxidation in the ileum of the SAO-shocked, GITR wild-type (WT) mice after reperfusion. The absence of GITR significantly reduced the lipid peroxidation in the intestine. SAO-shocked WT mice developed a significant increase of ileum tissue, TNF-alpha, and myeloperoxidase activity and marked histological injury. SAO shock was also associated with a significant mortality (5% survival at 24 h after reperfusion). Reperfused ileum tissue sections from SAO-shocked WT mice showed positive staining for P-selectin, intercellular adhesion molecule 1 (ICAM-1), and E-selectin. The intensity and degree of P-selectin, E-selectin, and ICAM-1 were markedly reduced in tissue section from SAO-shocked, GITR-KO mice. SAO-shocked, GITR-KO mice also showed a significant reduction of the TNF-alpha production and neutrophil infiltration into the reperfused intestine, an improved histological status of the reperfused tissues, and an improved survival. Taken together, our results clearly demonstrate that GITR plays an important role in the ischemia and reperfusion injury and put forward the hypothesis that modulation of GITR expression may represent a novel and possible strategy.

WY 14643, a potent exogenous PPAR-α ligand, reduces intestinal injury associated with splanchnic artery occlusion shock

Abstract: The peroxisome proliferator-activated receptor-alpha (PPAR-alpha) is a member of the nuclear receptor superfamily of ligand-dependent transcription factors related to retinoid, steroid, and thyroid hormone receptors. WY 14643 is a potent PPAR-alpha ligand that modulates the transcription of target genes. The aim of this study was to investigate the effect of WY 14643 on the tissue injury caused by ischemia-reperfusion (I/R) of the gut. I/R injury of the intestine was caused by clamping both the superior mesenteric artery and the celiac trunk for 45 min, followed by release of the clamp, allowing reperfusion for 2 h or 4 h. This procedure results in splanchnic artery occlusion (SAO) shock. Rats subjected to SAO developed a significant fall in mean arterial blood pressure, and only 20% of the animals survived for the entire 4-h reperfusion period. Surviving animals were sacrificed for histological examination and biochemical studies. Rats subjected to SAO displayed a significant increase in tissue myeloperoxidase (MPO) activity, significant increases in plasma tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta levels, and marked injury to the distal ileum. Increased immunoreactivity to nitrotyrosine and polyadenosine diphosphate [ADP]-ribose (PAR) was observed in the ileum of rats subjected to SAO. Staining of sections of the ileum obtained from SAO rats with anti-intercellular adhesion molecule (ICAM-1) antibody or with anti-P-selectin antibody resulted in diffuse staining. Administration of WY 14643 (1 mg/kg i.v.) 30 min before the onset of gut ischemia significantly reduced the (a) fall in mean arterial blood pressure, (b) mortality rate, (c) infiltration of the reperfused intestine with polymorphonuclear neutrophils (MPO activity), (d) production of proinflammatory cytokines (TNF-alpha and IL-1beta), and (e) histological evidence of gut injury. Administration of WY 14643 also markedly reduced the nitrotyrosine formation, poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP) activation, up-regulation of ICAM-1, and expression of P-selectin during reperfusion. These results demonstrate that the PPAR-alpha agonist WY 14643 significantly reduces I/R injury of the intestine.

Hyperbaric oxygen therapy prevents vascular derangement during zymosan-induced multiple-organ-failure syndrome.

Abstract: This study investigated the effects of hyperbaric oxygen (HBO) therapy on the cardiovascular alteration (e.g. mean arterial pressure, vascular reactivity of thoracic aorta rings changes) caused by zymosan in rats. Rats. University research laboratory. We investigated the effects of HBO therapy (2 ATA at the fourth and eleventh hours after study onset) on the cardiovascular alteration caused by zymosan (500 mg/kg, administered i.p. as a suspension in saline) in rats. Cardiovascular alterations were assessed 18 h after administration of zymosan and/or HBO therapy. Treatment of rats with HBO therapy attenuated the vasoplegic response to zymosan. In fact, the analysis of arterial pressure curves revealed no signs of vasoplegic shock. The aorta rings of animals treated with zymosan and HBO had a significantly increased contraction to norepinephrine (NE) and endothelin-1 (ET-1) and dilation to acetylcholine (ACh) compared with the zymosan group. The HBO therapy also attenuated the increase of malondialdehyde (MDA) levels caused by zymosan in the aorta. Immunohistochemical analysis for nitrotyrosine and for iNOS revealed positive staining in the aorta from zymosan-treated rats. The degree of staining for nitrotyrosine and iNOS was markedly reduced in tissue sections obtained from zymosan-rats treated with HBO therapy. This study provides the first evidence that HBO therapy attenuates the degree of zymosan-induced cardiovascular derangement in the rat.

Role of 5-lipoxygenase in the multiple organ failure induced by zymosan.

Abstract: Objective This study investigated the role of 5-lipoxygenase in the pathogenesis of multiple organ failure (MOF) induced by zymosan.

Calpain inhibitor I reduces intestinal ischemia-reperfusion injury in the rat.

Abstract: In this study we evaluated the effect of calpain inhibitor I on splanchnic artery occlusion (SAO) shock-mediated injury. SAO shock was induced in rats by clamping both the superior mesenteric artery and the celiac trunk for 45 min. After 1 h of reperfusion, SAO-shocked rats developed a significant fall in mean arterial blood pressure. Western blot analysis of ileum revealed a marked decrease in of IkappaB-alpha expression, and immunohistochemical examination of necrotic ileum demonstrated a marked increase in the immunoreactivity to P-selectin, intracellular adhesion molecule (ICAM-1), nitrotyrosine formation, and nuclear enzyme poly[adenosine diphosphate (ADP)-ribose] synthase (PARS) activation. An increase in myeloperoxidase activity (143 +/- 22 4.5 U/100 mg wet tissue vs. 4.5 +/- 2.5 U/100 mg wet tissue of sham-operated rats) and in malondialdehyde levels (13.12 +/- 1.2 micromol/100 mg wet tissue vs. 3.9 +/- 1.1 micromol/100 mg wet tissue of sham-operated rats) was also observed in rats subjected to ischemia-reperfusion injury. Calpain inhibitor I, given intraperitoneally 30 min before ischemia at a dose of 15 mg/kg, significantly improved mean arterial blood pressure, markedly reduced IkappaB-alpha degradation and the intensity of P-selectin and ICAM-1 in the reperfused ileum. Calpain inhibitor I also significantly prevented neutrophil infiltration (32.95 +/- 9.82 U/100 mg wet tissue), reduced malondialdehyde levels (6.76 +/- 0.98 micromol/100 mg wet tissue) and markedly improved the histological status of the reperfused tissue. In conclusion, this study demonstrates that calpain inhibitor I exerts multiple protective effects in splanchnic artery occlusion-reperfusion shock and suggests that calpain inhibitor I may be a candidate for consideration as a therapeutic intervention for ischemia-reperfusion injury.

Protective effects of M40401, a selective superoxide dismutase mimetic, on zymosan-induced nonseptic shock.

Abstract: Objective: Zymosan enhances formation of reactive oxygen species, which contributes to the pathophysiology of organ failure during nonseptic shock. Here we have investigated the effects of M40401, a new superoxide dismutase mimetic, on the organ failure associated with nonseptic shock caused by zymosan in rats. Design: Experimental study. Setting: Laboratory. Subjects: Male Sprague-Dawley rats. Interventions: We investigated the effects of M40401 on the organ failure associated with nonseptic shock caused by zymosan (500 mg/kg, administered intraperitoneally as a suspension in saline) in rats. Measurements and Main Results: Organ failure and systemic inflammation in rats were assessed 18 hrs after administration of zymosan and/or M40401 and were monitored for 12 days (for loss of body weight and mortality). Treatment of rats with M40401 (10 mg/kg intraperitoneally, 1 and 6 hrs after zymosan) attenuated the peritoneal exudation and the migration of polymorphonuclear cells caused by zymosan. M40401 administration also attenuated the lung and intestinal injury (histology) as well as the increase in myeloperoxidase activity and malondialdehyde concentrations caused by zymosan in lung and intestine. Immunohistochemical analysis for nitrotyrosine and for poly(adenosine 5'-diphosphateribose) revealed positive staining in lung and intestine from zymosan-treated rats. The degree of staining for nitrotyrosine and poly(adenosine 5'-diphosphate-ribose) was markedly reduced in tissue sections obtained from zymosan-treated rats administered with M40401. Conclusion: This study provides the first evidence that M40401 attenuates the degree of zymosan-induced nonseptic shock in the rat.