fr-167653 and Hemorrhage

Hemorrhagic shock occasionally causes a fatal outcome following an outbreak of lung dysfunction, but the precise mechanism has not been clearly elucidated. Several studies have indicated that hemorrhagic shock causes a delayed vascular inflammatory decompensation and leads to inflammation-related organ dysfunction. Tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta are known as major proinflammatory cytokines that play an important role in excessive autolytic inflammation, finally inducing organ dysfunctions. In this study, the role of TNF-alpha and IL-1beta on lung dysfunction following hemorrhagic shock was examined by using FR167653, a potent inhibitor of TNF-alpha and IL-1beta production that acts by suppressing p38 mitogen-activated protein kinase (MAPK).. Hemorrhagic shock was induced in anesthetized male rats by bleeding via a common carotid catheter for 20 minutes to 25% of total body blood volume without fluid resuscitation. Mean blood pressure, heart rate and arterial blood gas components were recorded up to 5 hours after the bleeding. The levels of TNF-alpha, IL-1beta and lactic dehydrogenase (LDH)-3 isozyme were measured in the serum of pulmonary venous blood. The lung tissue was excised for the assay of mRNA and for histopathological study.. The expressions of mRNA for TNF-alpha and IL-1beta in the lung tissue and the concentrations of both cytokines in pulmonary serum increased after a hemorrhage. Inflammation-related injuries and function deterioration were observed in the lung following hemorrhagic shock. These hemorrhagic changes were inhibited by pretreatment with FR167653.. TNF-alpha and IL-1beta play a key role in the development of inflammation-related lung dysfunction following hemorrhagic shock. Our model should be useful to explain the pathogenesis of lung dysfunction following hemorrhagic shock.

Topics: Animals; Blood Gas Analysis; Hemorrhage; Humans; Inflammation; Interleukin-1beta; Lung; Male; MAP Kinase Signaling System; Pyrazoles; Pyridines; Rats; Rats, Wistar; Shock, Hemorrhagic; Treatment Outcome; Tumor Necrosis Factor-alpha

Hemorrhagic shock has been reported to induce renal dysfunction as a consequence of different kinds of local inflammatory response. p38 mitogen-activated protein kinase (MAPK) is a key mediator in organ dysfunction relating to the inflammatory states, and acts as an important mediator in the intracellular signal pathway for proliferation, differentiation, and production of proinflammatory cytokines such as TNF-alpha and IL-1beta. The effect of p38 MAPK on the hemorrhagic damage has not been clearly estimated as yet. In this study, our aim was to evaluate the role of p38 MAPK on the renal damage during the first 5 h after a hemorrhage using a specific inhibitor of p38 MAPK activation, FR167653. p38 MAPK activation increased immediately after a hemorrhage and decreased with time. renal mRNA expression of TNF-alpha and IL-1beta increased, renal dysfunction continued to progress, and histological inflammatory injuries were confirmed after hemorrhagic shock. With the pretreatment of FR167653, all of these hemorrhagic changes were attenuated, although the induction of the primary hypotensive state was confirmed. This study demonstrated that renal p38 MAPK is activated in hemorrhagic shock, promotes the expression of proinflammatory cytokines in the kidney, and consequently develops renal dysfunction. We concluded that p38 MAPK activation is essential in causing renal damage and that the inhibition of p38 MAPK activation blocks the development of the renal dysfunction after hemorrhagic shock.

Topics: Animals; Blood Urea Nitrogen; Blotting, Western; Cytokines; Hemorrhage; Immunohistochemistry; Inflammation; Interleukin-1; Kidney; Kidney Diseases; Male; Neutrophils; p38 Mitogen-Activated Protein Kinases; Pyrazoles; Pyridines; Rats; Rats, Wistar; RNA, Messenger; Shock, Hemorrhagic; Time Factors; Tumor Necrosis Factor-alpha

Mild haemorrhage occasionally causes delayed death following failure of kidney or multiple organs, but the precise mechanisms have not yet been identified. We investigated the role of tumour necrosis factor-alpha (TNF-alpha), known as a major pro-inflammatory cytokine that leads to multiple organ failure, on the renal damage induced by mild haemorrhage. A mild haemorrhagic state was induced in male anaesthetized rats by bleeding via a common carotid catheter for 20 min at 16.7% of total body blood, 1.09 ml/100 g body weight, without fluid resuscitation. Mean arterial pressure and heart rate decreased soon after haemorrhaging but returned to baseline level up to 5 h after bleeding. TNF-alpha mRNA expression in the kidney and serum TNF-alpha levels were highest at 1 h after bleeding. Intraperitoneal pretreatment with FR167653, an inhibitory compound of TNF-alpha production, as well as of interleukin (IL)-1beta, significantly inhibited the increase in TNF-alpha. The inflammatory cell infiltration and tubular cell injury induced by haemorrhage were suppressed, and the renal dysfunction was dramatically improved by the FR167653 treatment. The morphological changes were also less in the treated group than in those that had not been treated. TNF-alpha has been reported to have striking effects on IL-1beta release and activation of neutrophils, and to play a pivotal role in the expression of the other pro-inflammatory cytokines. Our data show that endogenously-derived TNF-alpha does play a key role in the renal dysfunction during mild haemorrhage. These results should be useful to forensic pathologists to explain the pathogenesis of renal dysfunction induced by a mild haemorrhage and to identify the cause of death where there are no significant morphological changes after mild haemorrhage.

Topics: Animals; Blood Pressure; Heart Rate; Hemorrhage; Immunosuppressive Agents; Interleukin-1; Kidney; Kidney Diseases; Kidney Tubules; Male; Neutrophils; Pyrazoles; Pyridines; Rats; Rats, Wistar; RNA, Messenger; Tumor Necrosis Factor-alpha