RESUMO
BACKGROUND: The goal of this study was to investigate whether exogenous offer of L-arginine (LARG) modulates the gene expression of intestinal dysfunction caused by ischemia and reperfusion. METHODS: Eighteen Wistar-EPM1 male rats (250-300 g) were anesthetized and subjected to laparotomy. The superior mesenteric vessels were exposed, and the rats were randomized into 3 groups (n = 6): the control group (CG), with no superior mesenteric artery interruption; the ischemia/reperfusion group (IRG), with 60 minutes of ischemia and 120 minutes of reperfusion and saline injections; and the L-arginine group (IRG + LARG), with L-arginine injected in the femoral vein 5 minutes before ischemia, 5 minutes after reperfusion, and after 55 minutes of reperfusion. The total RNA was extracted and purified from samples of the small intestine. The concentration of each total RNA sample was determined by using spectrophotometry. The first-strand complementary DNA (cDNA) was synthesized in equal amounts of cDNA and the Master Mix SYBR Green qPCR Mastermix (SABiosciences, a Qiagen Company, Frederick, Md). Amounts of cDNA and Master Mix SYBR Green qPCR Mastermix were distributed to each well of the polymerase chain reaction microarray plate containing the predispensed gene-specific primer sets for Bax and Bcl2. Each sample was evaluated in triplicate, and the Student t test was applied to validate the homogeneity of each gene expression reaction (P < .05). RESULTS: The gene expression of Bax in IRG (+1.48) was significantly higher than in IRG-LARG (+9.69); the expression of Bcl2L1 in IRG (+1.01) was significantly higher than IRG-LARG (+22.89). CONCLUSIONS: The apoptotic cell pathway of 2 protagonists showed that LARG improves the gene expression of anti-apoptotic Bcl2l1 (Bcl2-like 1) more than the pro-apoptotic Bax (Bcl2-associated X protein).
Assuntos
Arginina/farmacologia , Intestino Delgado/irrigação sanguínea , Intestino Delgado/metabolismo , Isquemia/metabolismo , Traumatismo por Reperfusão/metabolismo , Proteína X Associada a bcl-2/metabolismo , Animais , Apoptose , Intestino Delgado/patologia , Isquemia/complicações , Isquemia/patologia , Masculino , Artéria Mesentérica Superior , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Distribuição Aleatória , Ratos , Ratos Wistar , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/patologia , Proteína X Associada a bcl-2/genéticaRESUMO
Although assist ventilation with FIO2 0.21 is the preferable mode of ventilation in the intensive care unit, sometimes controlled ventilation with hyperoxia is needed. But the impact of this setting has not been extensively studied in elderly subjects. We hypothesized that a high fraction of inspired oxygen (FiO(2)) and controlled mechanical ventilation (CMV) is associated with greater deleterious effects in old compared to adult subjects. Adult and old rats were submitted to CMV with low tidal volume (6 ml/kg) and FiO(2) 1 during 3 or 6 h. Arterial blood gas samples were measured at 0, 60 and 180 min (four groups: old and adult rats, 3 or 6 h of CMV), and additionally at 360 min (two groups: old and adult rats, 6 h of CMV). Furthermore, total protein content (TPC) and tumor necrosis factor-alpha (TNF-α) in bronchoalveolar lavage were assessed; lung tissue was used for malondialdehyde and histological analyses, and the diaphragm for measurement of contractile function. Arterial blood gas analysis showed an initial (60 min) greater PaO(2) in elderly versus adult animals; after that time, elderly animals had lowers pH and PaO(2), and greater PaCO(2). After 3 h of CMV, TPC and TNF-α levels were higher in the old compared with the adult group (P < 0.05). After 6 h of MV, malondialdehyde was significantly higher in elderly compared with the adult animals (P < 0.05). Histological analysis showed leukocyte infiltration and edema, greater in old animals. In diaphragm, twitch contraction with caffeine significantly declined after 6 h of CMV only for the elderly group. These data support the hypothesis that relatively short-term CMV with low tidal volume and hyperoxia has greatest impact in elderly rats, decreasing diaphragmatic contractile function and increasing lung inflammation.
Assuntos
Diafragma/fisiopatologia , Hiperóxia/complicações , Pulmão/fisiopatologia , Pneumonia Associada à Ventilação Mecânica/etiologia , Respiração Artificial/efeitos adversos , Fatores Etários , Animais , Gasometria , Líquido da Lavagem Broncoalveolar/química , Modelos Animais de Doenças , Hiperóxia/sangue , Hiperóxia/imunologia , Hiperóxia/patologia , Hiperóxia/fisiopatologia , Mediadores da Inflamação/metabolismo , Pulmão/imunologia , Pulmão/patologia , Masculino , Malondialdeído/metabolismo , Contração Muscular , Pneumonia Associada à Ventilação Mecânica/sangue , Pneumonia Associada à Ventilação Mecânica/imunologia , Pneumonia Associada à Ventilação Mecânica/patologia , Pneumonia Associada à Ventilação Mecânica/fisiopatologia , Ratos , Ratos Wistar , Fatores de Risco , Volume de Ventilação Pulmonar , Fatores de Tempo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
To study whether ischemic preconditioning (IPC) attenuated intestinal dysfunction caused by ischemia (I) and reperfusion (R), rats were underwent 60 minutes of I which was produced by occlusion of the superior mesenteric artery, and/or 120 minutes R. The IPC group had the I procedure previously stimulated for 5 minutes and the R for 10 minutes. IPC and sham groups were injected with saline solution (SS) via the femoral vein 5 minutes before the I and R, and for R. After I or I/R, 2-cm jejunal segments were mounted in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained with hematoxylin and eosin for optical microscopy. Compared with the sham group, jejunal contractions were similar in the IPC + I and the IPC + I/R groups, but reduced in the I + SS and the I/R + SS groups. The jejunal enteric nerves were damaged in the I + SS and the I/R + SS groups, but not in the IPC groups. These results suggested that ischemic preconditioning attenuated intestinal dysfunction caused by I and I/R.
Assuntos
Precondicionamento Isquêmico , Jejuno/irrigação sanguínea , Traumatismo por Reperfusão/prevenção & controle , Animais , Modelos Animais de Doenças , Estimulação Elétrica , Sistema Nervoso Entérico/fisiopatologia , Motilidade Gastrointestinal , Jejuno/efeitos dos fármacos , Jejuno/inervação , Jejuno/patologia , Jejuno/fisiopatologia , Masculino , Cloreto de Potássio/farmacologia , Ratos , Ratos Wistar , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/fisiopatologiaRESUMO
To examine whether treatment with L-arginine (ARG), a substrate of nitric oxide biosynthesis, attenuated intestinal dysfunction caused by ischemia (I) and reperfusion (R), we treated rats with ARG (100 mg/kg intravenously) or saline solution (SS) before 60 minutes of I produced by occlusion of the superior mesenteric artery and/or during 120 minutes of R. After I or I/R, we isolated 2-cm jejunal segments for mounting in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl with the use of a digital recording system. Thin jejunal slices were stained with hematoxylin and eosin for optical microscopy. Jejunal contractions were similar in the sham and I+ARG, but reduced in I+SS, I/R+SS, and I/R+ARG groups. Jejunal enteric nerves were damaged in I+SS, IR+SS, and IR+ARG, but not in the I+ARG group, suggesting that ARG attenuate intestinal dysfunctions due to I but not to R.
Assuntos
Arginina/farmacologia , Fármacos Gastrointestinais/farmacologia , Jejuno/irrigação sanguínea , Jejuno/efeitos dos fármacos , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Citoproteção , Modelos Animais de Doenças , Estimulação Elétrica , Sistema Nervoso Entérico/efeitos dos fármacos , Sistema Nervoso Entérico/fisiopatologia , Motilidade Gastrointestinal/efeitos dos fármacos , Jejuno/inervação , Jejuno/patologia , Jejuno/fisiopatologia , Masculino , Cloreto de Potássio/farmacologia , Ratos , Ratos Wistar , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/fisiopatologiaRESUMO
To study whether treatment with the beta-blocker atenolol (AT) attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), rabbits were treated with AT (1 mg.kg(-1), introvenously) or saline solution (SS) prior to I (60 minutes), which was produced by occlusion of the superior mesenteric artery, and/or R (120 minutes). After I or I/R, 2-cm jejunal segments were mounted in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained hematoxylin and eosin for analysis by optical microscopy. Compared to the sham group, the jejunal contractions were similar in the I + AT and the I/R + AT groups, but reduced in the I + SS and the I/R + SS groups. The jejunal enteric nerves were damaged in the I + SS and the I/R + SS groups, but not in the I + AT and the I/R + AT. These results suggest that AT may attenuate intestinal dysfunction caused by I and I/R.
Assuntos
Atenolol/uso terapêutico , Enteropatias/tratamento farmacológico , Intestinos/irrigação sanguínea , Jejuno/fisiologia , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Circulação Sanguínea , Estimulação Elétrica , Enteropatias/etiologia , Jejuno/irrigação sanguínea , Jejuno/efeitos dos fármacos , Masculino , Artéria Mesentérica Superior/fisiologia , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Cloreto de Potássio/farmacologia , CoelhosRESUMO
To study if the treatment with adenosine (ADO), an agonist of adenosine receptors, attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), we treated rabbits with ADO (15 mg x kg(-1), intravenously) or saline solution (SS) to I (60 minutes) before occlusion of superior mesenteric artery and/or R (120 min). After I or I/R, isolated jejunal segments (2 cm) were mounted in an organ bath to study nerve-mediated contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained (hematoxylin and eosin) for analysis by optical microscopy. Compared to the sham group, the jejunal contractions were similar in I + ADO, but reduced in I + SS, I/R + SS, and I/R + ADO groups. We concluded that the jejunal enteric nerves were damaged in I + SS, I/R + SS, and I/R + ADO, but not in I + ADO group. These results suggested that ADO attenuated intestinal dysfunction due to I, but not to R.
Assuntos
Adenosina/farmacologia , Intestinos/irrigação sanguínea , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Circulação Sanguínea , Estimulação Elétrica , Veia Femoral/efeitos dos fármacos , Veia Femoral/fisiologia , Jejuno/irrigação sanguínea , Jejuno/efeitos dos fármacos , Jejuno/fisiologia , Masculino , Artéria Mesentérica Superior/fisiologia , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Cloreto de Potássio/farmacologia , Agonistas do Receptor Purinérgico P1 , Coelhos , Cloreto de Sódio/farmacologiaRESUMO
To study whether treatment with L-nitro-arginine methyl ester (L-NAME), an inhibitor of nitric oxide biosynthesis, attenuates intestinal dysfunction caused by ischemia (I) and/or reperfusion (R), rabbits were treated with L-NAME (15 mgxkg(-1), intervenously) or saline olution (SS) prior to I (60 minutes) induced by occlusion of superior mesenteric artery and/or R (120 minutes). After I or I/R, isolated jejunal segments (2 cm) were mounted in an organ bath to study nerve-mediated contractions stimulated by electrical pulses or KCI using a digital recording system. Thin jejunal slices were stained (hematoxylin and eosin) for analysis by optical microscopy. Compared with a sham group, the jejunal contractions were similar in the I/R + L-NAME, but reduced in I + SS, I/R + SS, and I + L-NAME groups. The jejunal enteric nerves were damaged in the I + SS, I/R + SS, and I + L-NAME cohorts, but not among the I/R + L-NAME cohort. These results suggested that L-NAME attenuated intestinal dysfunction caused by R but not by I.
Assuntos
Motilidade Gastrointestinal/efeitos dos fármacos , Enteropatias/prevenção & controle , NG-Nitroarginina Metil Éster/farmacologia , Traumatismo por Reperfusão/prevenção & controle , Traumatismo por Reperfusão/fisiopatologia , Animais , Estimulação Elétrica , Isquemia/fisiopatologia , Jejuno/efeitos dos fármacos , Jejuno/inervação , Jejuno/fisiologia , Masculino , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Coelhos , Cloreto de Sódio/farmacologiaRESUMO
To study whether treatment with 5'-adenosine triphosphate (ATP), an agonist of P2 purine receptors, attenuated intestinal dysfunction caused by ischemia (I) and/or reperfusion (R), rabbits were treated with ATP (15 mgxkg(-1), intravenously) or saline solution (SS) 60 minutes before I by occlusion of the superior mesenteric artery and/or R (120 minutes). After I or I/R isolated 2-cm jejunal segments were mounted in an organ bath to study nerve-mediated contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained (hematoxylin and eosin) for optical microscopy. Compared to a sham group, the jejunal contractions were similar to sham hosts among I + ATP, but reduced in I + SS, I/R + SS, and I/R + ATP groups. The jejunal-enteric nerves were damaged in I + SS, I/R + SS, and I/R + ATP, but not the I + ATP group. These results suggested that ATP attenuated intestinal dysfunction produced by I, but not that caused by R.
Assuntos
Trifosfato de Adenosina/farmacologia , Intestinos/irrigação sanguínea , Isquemia/fisiopatologia , Jejuno/irrigação sanguínea , Traumatismo por Reperfusão/fisiopatologia , Animais , Circulação Sanguínea/efeitos dos fármacos , Circulação Sanguínea/fisiologia , Isquemia/tratamento farmacológico , Jejuno/efeitos dos fármacos , Jejuno/inervação , Masculino , Artéria Mesentérica Superior/efeitos dos fármacos , Artéria Mesentérica Superior/fisiopatologia , Coelhos , Cloreto de Sódio/farmacologiaRESUMO
In this work, we evaluate the effects of adenosine 5' triphosphate (ATP) on hepatic lesions caused by ischemia/reperfusion (I/R) in liver rabbit. Rabbits were pretreated with ATP (15 mg/kg IV) or saline solution 0.9% (SS), before the hepatic I/R procedure. We evaluated the effects of ATP on hepatic injury before and after I/R. The warm hepatic I/R procedure caused profound acute liver injury, as indicated by elevated serum aspartate aminotransferase, alanine aminotransferase, and lactic dehydrogenase levels, as well as a high apoptotic cell count. All these changes were attenuate by ATP treatment before the hepatic I/R procedure. These results suggested that ATP exerted protective effects on hepatic I/R lesions in the rabbit. This ATP effect may be related to improved energy metabolism during reperfusion in ischemic livers protecting against functional damage of cellular and subcellular membranes during lipid peroxidation.
Assuntos
Hepatopatias/fisiopatologia , Purinas/metabolismo , Traumatismo por Reperfusão/fisiopatologia , Trifosfato de Adenosina/uso terapêutico , Alanina Transaminase/efeitos dos fármacos , Alanina Transaminase/metabolismo , Animais , Aspartato Aminotransferases/efeitos dos fármacos , Aspartato Aminotransferases/metabolismo , Isquemia/fisiopatologia , L-Lactato Desidrogenase/efeitos dos fármacos , L-Lactato Desidrogenase/metabolismo , Fígado/efeitos dos fármacos , Fígado/fisiopatologia , Hepatopatias/prevenção & controle , Masculino , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias Hepáticas/metabolismo , Coelhos , Traumatismo por Reperfusão/prevenção & controleRESUMO
We evaluated the effects of a substrate in the biosynthesis of nitric oxide (NO)-l-arginine (LARG)-on hepatic lesions caused by ischemia/reperfusion (I/R) injury in rabbit livers. Rabbits were pretreated with LARG (150 mg/kg IV) or saline solution 0.9% (SS) before the hepatic I/R procedure. The effects of LARG on hepatic injury were evaluated before and after I/R. The warm hepatic I/R procedure produced profound acute liver injury, as indicated by elevated values of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactic dehydrogenase (LDH), as well as a high apoptotic cell count. All changes were attenuated by treatment with LARG before the hepatic I/R procedure. These results suggested that LARG produced protective effects on hepatic I/R lesions. This protective effect of LARG was probably associated with blocking generation of superoxide anions during the hepatic I/R procedure.