Effects of therapeutic hypercapnia on inflammation and apoptosis after hepatic ischemia-reperfusion injury in rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Therapeutic hypercapnia (TH) has been demonstrated to protect several organs ischemia-reperfusion injury. The study aimed to investigate the effects of therapeutic hypercapnia on hepatic ischemia-reperfusion injury (HIRI).</p><p><b>METHODS</b>Thirty adult male Wistar rats weighing (250+/-20) g were randomized into 3 groups (n=10 in each), group C (control group), group A (hypercapnia group) and group B (CO2 preconditioning group). A segmental ischemia of the liver was induced by interrupting the blood vessels including the bile duct to the median and left lateral lobes for 60 minutes and all the animals were sacrificed after 240 minutes observation period of reperfusion. Mean arterial pressure (MAP) and the blood gases were measured before ischemia (baseline) and at 30, 60, 120, 180 and 240 minutes after reperfusion. Arterial blood samples were obtained for determination of serum levels of TNF-alpha, IL-10, serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The histopathology of liver tissues was evaluated by light microscopy. The NF-kappaB expression and apoptotic hepatocytes were respectively determined by immunohistochemistry and TUNEL assay.</p><p><b>RESULTS</b>The serum levels of liver enzymes and TNF-alpha were significantly decreased while the IL-10 level was significantly increased in groups A and B than in group C (P<0.05), and group B surpassed group A (P<0.05). The histopathological scores, the NF-kappaB immunohistochemical score (IHS) and apoptotic index were significantly lower in groups A and B than in group C (P<0.05), and the decrease in group B was more obvious than in group A (P<0.05).</p><p><b>CONCLUSION</b>Therapeutic hypercapnia attenuates ischemia-reperfusion injury to the liver. Moreover, the effects of CO2 preconditioning are outstandingly notable.</p>

Anti-apoptotic effect of morphine-induced delayed preconditioning on pulmonary artery endothelial cells with anoxia/reoxygenation injury / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Opioid preconditioning (PC) reduces anoxia/reoxygenation (A/R) injury to various cells. However, it remains unclear whether opioid-induced delayed PC would show anti-apoptotic effects on pulmonary artery endothelial cells (PAECs) suffering from A/R injury. The present study was conducted to elucidate this issue and to investigate the potential mechanism of opioid-induced delayed PC.</p><p><b>METHODS</b>Cultured porcine PAECs underwent 16-hour anoxia followed by 1-hour reoxygenation 24 hours after pretreatment with saline (NaCl; 0.9%) or morphine (1 micromol/L). To determine the underlying mechanism, a non-selective K(ATP) channel inhibitor glibenclamide (Glib; 10 micromol/L), a nitric oxide (NO) synthase blocker NG-nitro-L-arginine methyl ester (L-NAME; 100 micromol/L), and an opioid receptor antagonist naloxone (Nal; 10 micromol/L) were given 30 minutes before the A/R load. The percentage of apoptotic cells was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. eNOS mRNA level was measured by real-time polymerase chain reaction (PCR). NO content of PAECs supernatants was measured with the Griess reagent.</p><p><b>RESULTS</b>Compared to the A/R PAECs, morphine-induced delayed PC significantly reduced PAECs apoptosis ((18.1 +/- 1.9)% vs (5.5 +/- 0.3)%; P < 0.05), increased NO release ((11.4 +/- 1.3) micromol/L vs (20.5 +/- 2.1) micromol/L, P < 0.05), and up-regulated eNOS gene expression nearly 9 times (P < 0.05). The anti-apoptosis effect of morphine was abolished by pretreatment with Glib, L-NAME and Nal, but the three agent-selves did not aggravate the A/R injury. Furthermore, L-NAME and Nal offset the enhanced release of NO caused by pretreatment with morphine.</p><p><b>CONCLUSIONS</b>Morphine-induced delayed PC prevents A/R injury of PAECs. This effect may be mediated by activation of K(ATP) channel via opioid receptor and NO signaling pathways.</p>