Fwu-Lin Yang

Melatonin Ameliorates Hemorrhagic Shock-Induced Organ Damage in Rats

BACKGROUND Hemorrhagic shock (HS) followed by resuscitation can result in production of several inflammatory mediators, such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), leading to multiple organ dysfunction. Melatonin can attenuate organ damage with its anti-inflammation effects. The present study was designed to investigate the effects of melatonin on the physiopathology and cytokine levels after HS in rats. METHODS HS was induced in rats by withdrawing 40% of the total blood volume (6 mL/100 gm body weight) from a femoral artery catheter, immediately followed by intravenous injection of 10mg/kg melatonin. Mean arterial pressure and heart rate were monitored continuously for 48 h after the start of blood withdrawal. Biochemical parameters, including levels of hemoglobulin, glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), blood urea nitrogen (BUN), creatinine (Cre), lactic dehydrogenase (LDH), creatine phosphokinase (CPK), and lactate, were determined 30 min before and 0, 1, 3, 6, 12, 24, and 48 h after induction of HS while an equal volume of normal saline was replaced as fluid resuscitation. Cytokine levels including TNF-α and IL-6 in the serum were measured at 1, 24, and 48 h after HS. The kidney, liver, lung, and small intestine were removed for pathology assessment at 48 h after HS. RESULTS HS significantly increased the heart rate, blood GOT, GPT, BUN, Cre, LDH, CPK, lactate, TNF-α, and IL-6 levels, and decreased hemoglobulin and mean arterial pressure in rats. Treatment with melatonin preserved the mean arterial pressure, decreased tachycardia, and markers of organ injury, and suppressed the release of TNF-α and IL-6, with no change in hemoglobulin after HS in rats. CONCLUSION Treatment with melatonin suppresses the release of serum TNF-α and IL-6, and decreases the levels of markers of organ injury associated with HS, thus ameliorating HS-induced organ damage in rats.

Recombinant human erythropoietin reduces rhabdomyolysis-induced acute renal failure in rats

BACKGROUND Rhabdomyolysis is one of the causes of acute renal failure. Erythropoietin (EPO) has been found to interact with its receptor (EPO-R) expressed in a large variety of non-haematopoietic tissues to induce a range of pleiotropic cytoprotective actions. In this study, we used recombinant human erythropoietin (rhEPO) to study the effects on the glycerol-induced rhabdomyolysis with acute renal failure in rats. METHODS Twenty-four rats were divided into three groups as glycerol group, glycerol+EPO group and normal saline+EPO group. Rhabdomyolysis was induced by intramuscular injection of 10 mlkg(-1) 50% glycerol in rats. Ten minutes later, the rats received an intravenous injection of rhEPO (300 Ukg(-1)). Biochemical substances, including haemoglobin, blood urea nitrogen (BUN), creatinine (Cre), glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT) and creatine phosphokinase (CPK), were measured at 0, 1, 3, 6, 9, 12, 18, 24 and 48 h. Rats were sacrificed 48 h later after glycerol administration and the kidneys were removed immediately for pathology and immunohistochemistry (IHC). RESULTS Intramuscular injection of glycerol significantly increased blood BUN, Cre, GOT, GPT and CPK levels and induced severe histopathologic damage in the kidneys. Nuclear factor-κB (NF-κB) and inducible nitric oxide synthase (iNOS) were increased and E-cadherin was decreased after glycerol administration, as detected by IHC in the kidneys. Post-treatment with rhEPO decreased blood BUN, Cre, GOT, GPT and CPK levels, decreased markers of kidney injury and suppressed the release of NF-κB and iNOS after rhabdomyolysis. CONCLUSION Treatment with rhEPO suppressed the activities of NF-κB and iNOS, decreased BUN, Cre, GOT, GPT and CPK levels, and decreased the markers of kidney injury after rhabdomyolysis. These actions ameliorated rhabdomyolysis-induced acute renal failure in rats.

Vitamin D3 Reduces Tissue Damage and Oxidative Stress Caused by Exhaustive Exercise.

Exhaustive exercise results in inflammation and oxidative stress, which can damage tissue. Previous studies have shown that vitamin D has both anti-inflammatory and antiperoxidative activity. Therefore, we aimed to test if vitamin D could reduce the damage caused by exhaustive exercise. Rats were randomized to one of four groups: control, vitamin D, exercise, and vitamin D+exercise. Exercised rats received an intravenous injection of vitamin D (1 ng/mL) or normal saline after exhaustive exercise. Blood pressure, heart rate, and blood samples were collected for biochemical testing. Histological examination and immunohistochemical (IHC) analyses were performed on lungs and kidneys after the animals were sacrificed. In comparison to the exercise group, blood markers of skeletal muscle damage, creatine kinase and lactate dehydrogenase, were significantly (P < 0.05) lower in the vitamin D+exercise group. The exercise group also had more severe tissue injury scores in the lungs (average of 2.4 ± 0.71) and kidneys (average of 3.3 ± 0.6) than the vitamin D-treated exercise group did (1.08 ± 0.57 and 1.16 ± 0.55). IHC staining showed that vitamin D reduced the oxidative product 4-Hydroxynonenal in exercised animals from 20.6% to 13.8% in the lungs and from 29.4% to 16.7% in the kidneys. In summary, postexercise intravenous injection of vitamin D can reduce the peroxidation induced by exhaustive exercise and ameliorate tissue damage, particularly in the kidneys and lungs.

Effects of Freshwater Clam Extract Supplementation on Time to Exhaustion, Muscle Damage, Pro/Anti-Inflammatory Cytokines, and Liver Injury in Rats after Exhaustive Exercise

The potent anti-inflammatory activities and tissue-protective effects of freshwater clams (Corbicula fluminea) have been well reported. The aim of this study was to determine the effects of freshwater clam extract (FCE) supplementation on time to exhaustion, muscle damage, pro- and anti-inflammatory cytokines, and liver injury in rats after exhaustive exercise. Thirty-two rats were divided into four groups: sedentary control (SC); SC group with FCE supplementation (SC+FCE); exhaustive exercise (E); and E group with FCE supplementation (E+FCE). The SC+FCE and E+FCE groups were treated with gavage administration of 20 mg/kg for seven consecutive days. Blood samples were collected for the evaluation of biochemical parameters. The cytokine levels of TNF-α and IL-10 were also examined. Twenty-four hours after exhaustive exercise, the rat livers were removed for H & E staining. The FCE supplementation could extend the time to exhaustion in exercised rats. The levels of CPK, LDH, AST, ALT, lactate, TNF-α and H & E stains of the liver injury were significantly decreased in the E+FCE group, but the blood glucose and IL-10 were significantly higher in comparison with the E group. This study suggests that FCE supplementation may improve endurance performance and reduce exercise-induced muscle damage, inflammatory stress and liver injury.

Hypothermia caused by slow and limited-volume fluid resuscitation decreases organ damage by hemorrhagic shock

BACKGROUND Hypothermia frequently occurs during fluid resuscitation of trauma victims, especially in patients with a major blood loss. Recent studies have suggested that mild hypothermia may ameliorate hemorrhagic shock (HS) induced splanchnic damage. OBJECTIVE The aim of the present study is to compare the status of body temperature and splanchnic injury under different resuscitation speeds for HS in conscious rats. METHODS Experimental study in an animal model of HS. Twenty-four male Wistar-Kyoto rats were used in the study. To mimic HS, 40% of the total blood volume was withdrawn. Fluid resuscitation was given 30 min after blood withdrawal. The rats were randomly divided into three groups; the control group, the 10-min rapid group, and the 12-h slow group. RESULTS Levels of blood biochemical parameters, including aspartate transferase (GOT), and alanine transferase (GPT), were measured. Levels of serum tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) were measured and levels of bronchoalveolar lavage fluid (BALF) TNF-α and nitric oxide (NO) were measured by ELISA. The lung, liver and small intestine were examined for pathological changes 48 h after HS. CONCLUSIONS Initially slow rate resuscitation with limited-volume significantly decreased body temperature, serum GOT, GPT, TNF-α, and IL-6 levels, levels of TNF-α, and NO in BALF. Moreover, the slow group had lower injury scores in the lung, liver and small intestine than the rapid group after HS. This finding suggests that mild hypothermia induced by a slow fluid resuscitation rate with limited-volume ameliorates HS-induced splanchnic damage in conscious rats.

Deleterious effects of aggressive rapid crystalloid resuscitation on treatment of hyperinflammatory response and lung injury induced by hemorrhage in aging rats.

BACKGROUND Large-volume, rapid crystalloid infusion may increase endothelial cell damage and induce shear stress, potentially leading to multiple-organ dysfunction syndrome. Limited guideline data for fluid administration are currently available, especially for the aging population. The aim of the present study was to compare the degree of organ damage in conscious aging rats when different resuscitation speeds were used during the treatment of hemorrhagic shock (HS). METHODS Eighteen aging male Wistar-Kyoto rats were randomly divided into the following three groups: the control group, 30-min rapid resuscitation group, and 12-h slow resuscitation group. To mimic HS, 40% of the total blood volume was withdrawn. Fluid resuscitation (1:3) was given at 30 min after the blood withdrawal. Blood biochemical parameters including glucose, lactic acid, and lactate dehydrogenase (LDH) were measured along with the levels of serum and bronchoalveolar lavage fluid, tumor necrosis factor alpha (TNF-α), and interleukin 10 by enzyme-linked immunosorbent assay. The lungs were examined for pathologic changes, and the injury score at 24 h after HS was calculated. RESULTS Compared with slow-rate resuscitation, initially rapid and immediate resuscitation significantly increased the serum levels of glucose, LDH, and proinflammatory cytokines (TNF-α and interleukin 10), and bronchoalveolar lavage fluid levels of white blood cells, TNF-α, and LDH as well as produced pathologic changes in the organ. The lung injury scores were higher after induced HS in aging rats. CONCLUSIONS The slow and continuous (12 h) fluid resuscitation rate ameliorated HS-induced organ damage in conscious aging rats.

Pentobarbital reduces rhabdomyolysis-induced acute renal failure in conscious rats.

BACKGROUND Rhabdomyolysis is one of the causes of acute renal failure. Pentobarbital enhances the action of gamma-aminobutyric acid and suppresses the activities of nuclear factor (NF)-kappaB pathways. In this study, we used pentobarbital to study the effects on the glycerol-induced rhabdomyolysis with acute renal failure in conscious rats. METHODS Rhabdomyolysis was induced by intramuscular injection of 10 mL/kg of 50% glycerol in conscious rats. Ten minutes later, the rats received an intravenous injection of pentobarbital (10 mg/kg in 0.5 mL/h normal saline) or normal saline (0.5 mL/h). Biochemical substances, including blood urea nitrogen (BUN), creatinine (Cre), glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), and creatine phosphokinase (CPK) were measured at 0 hour, 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours. Rats were killed by decapitation at 48 hours after glycerol administration, and the kidneys were removed immediately for pathological findings and immunohistochemistry. RESULTS Intramuscular injection of glycerol significantly increased blood BUN, Cre, GOT, GPT, CPK levels and induced severe histopathologic damage in the kidneys. NF-kappaB and inducible nitric oxide synthase (iNOS) were increased, and E-cadherin was decreased after glycerol administration, as detected by immunohistochemistry in the kidneys. Posttreatment with pentobarbital decreased blood BUN, Cre, GOT, GPT, CPK levels, decreased the markers of kidney injury, and suppressed the release of NF-kappaB and iNOS after rhabdomyolysis. CONCLUSION Posttreatment with pentobarbital suppressed the activities of NF-kappaB and iNOS, decreased BUN, Cre, GOT, GPT, CPK levels, and decreased the markers of kidney injury after rhabdomyolysis. These actions ameliorated rhabdomyolysis-induced acute renal failure in conscious rats.

The treatment of propofol induced the TGF-β1 expression in human endothelial cells to suppress endocytosis activities of monocytes.

Propofol anesthesia and sedation are known to downregulate the functions of many hematopoietic cells, such as macrophages and neutrophils, in vivo. However, the effects of propofol on secretion of the regulatory cytokine transforming growth factor β1 (TGF-β1) in vivo are unknown. In this study, the effects of propofol on TGF-β1 expression in human peripheral blood mononuclear cells, umbilical vein endothelial cells (HUVECs), lymphocytes (Jurkat) and monocytes (THP-1) were tested. Moreover, these sera were also tested for regulatory activity on monocyte endocytosis with or without treatment with the TGF-β1 pathway inhibitor SB431542. Propofol raised levels of both total and activated TGF-β1 in propofol-treated patient sera after surgical operations. Furthermore, propofol induced secretion of latent TGF-β1 in HUVEC cells and enhanced TGF-β1 activation in THP-1 and Jurkat cells in vitro. Additionally, sera from propofol-treated patients suppressed monocyte endocytosis ex vivo, an effect that was abrogated by the TGF-β1 pathway inhibitor SB431542.

Stability of Blood Biochemistry Levels in Animal Model Research: Effects of Storage Condition and Time

The purpose of this study was to compare whole blood and plasma in terms of the subsequent accuracy of blood lactate, glucose, lactate dehydrogenase (LDH), creatine phosphokinase (CPK), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) measurement. Blood samples were drawn from 8 male Wistar-Kyoto rats. The rats were homologous, weighed 300— 380 g, were housed in the same environment, and were provided with food and water under the same conditions. Blood draws occurred in all rats at same time. The blood specimens were divided into two samples, one to be stored as whole blood (WBS) and one to be stored as plasma (PS). All the blood sample analyses were performed by trained and experienced personnel to ensure that differences in results were due to variation in form in which specimens were stored rather than to technique. The lactate concentration in the WBS group gradually increased over time, intraclass correlation coefficient (ICC) = 0.541, 95% confidence interval (CI; —0.197, 0.893), and was higher than that of the PS group, ICC = 0.897, 95% CI (0.733, 0.976). By contrast, glucose level gradually declined for the WBS group, ICC= —0.367, 95% CI (—2.563, 0.682). Whole blood storage increased measurement variation for lactate, glucose, LDH, and CPK. Plasma storage prolonged the stability of the biochemical components. This study demonstrates the importance of evaluating validity at each stage of developing and testing animal models.

Rosiglitazone protects against severe hemorrhagic shock-induced organ damage in rats

Summary Background Hemorrhagic shock (HS) followed by resuscitation can induce the production of several inflammatory mediators and lead to multiple organ dysfunction. The molecular mechanism of biologic responses to rosiglitazone has an anti-inflammatory effect. The present study was designed to investigate the effects of rosiglitazone on physiopathology and inflammatory mediators after HS in rats. Material/Methods HS was induced in rats by withdrawing 60% of the total blood volume from a femoral artery catheter, immediately followed by intravenous injection of 0.3 mg/kg rosiglitazone. Mean arterial pressure (MAP) and heart rate (HR) were monitored continuously for 12 h. Levels of biochemical parameters, including GOT, GPT, BUN, Cre, LDH, CPK, and lactate were measured at 30 min before induction of HS and 0, 1, 3, 6, 9, and 12 h after HS, while an equal volume of normal saline was replaced as fluid resuscitation. Inflammatory mediators, including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1), were measured in serum at 1 and 12 h after HS. The kidneys, liver, lungs, and small intestine were removed for histological assessment by hematoxylin and eosin stained at 48 h after HS. Results HS significantly increased blood GOT, GPT, BUN, Cre, LDH, CPK, lactate, glucose, TNF-α, IL-6 and MCP-1 levels, induced tachycardia, and decreased mean arterial pressure (MAP) in rats. Treatment with rosiglitazone improved survival rate, decreased the markers of organ injury, and suppressed the release of TNF-α, IL-6, and MCP-1 after HS in rats. Conclusions Treatment with rosiglitazone suppresses the release of serum TNF-α, IL-6 and MCP-1, and ameliorates HS-induced organ damage in rats.