P38 MAPK antisense oligodeoxynucleotide inhibited the brain ischemic tolerance induced by limb ischemic preconditioning / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To better assess the role of p38 MAPK, this project was designed to investigate whether intraventricular injection of antisense oligodeoxynucleotide (As-ODN) directed against the p38 MAPK of pyramidal neurons in hippocampus could affect the brain ischemic tolerance induced by limb ischemic preconditioning (LIP).</p><p><b>METHODS</b>The rat 4-vessel occlusion global cerebral ischemic model was used. Forty-eight male Wistar rats with permanently occlusion of the bilateral vertebral arteries were divided into 8 groups (n=6): sham, LIP, brain ischemic insult, LIP + brain ischemic insult, distilled water + LIP + brain ischemic insult, p38 MAPK As-ODN and p38 MAPK As-ODN + LIP + brain ischemic insult (two doses of 5 nmol/5 microl and 10 nmol/5 microl were used) groups. Thionin staining was used for observing histological changes of the hippocampus.</p><p><b>RESULTS</b>No significant delayed neuronal death (DND) was detected in the CA1 hippocampus of the rats that underwent sham and LIP operation. Brain ischemic insult for 8 min induced obvious DND as represented with the increase in histological grade (HG) and decrease in neuronal density (ND) significantly compared with sham and LIP groups. LIP protected the CA1 hippocampal pyramidal neurons against DND induced by global brain ischemic insult, suggesting the occurrence of brain ischemic tolerance. However, pretreatment with p38 MAPK As-ODN effectively blocked the ischemic tolerance induced by LIP in a dose dependent manner.</p><p><b>CONCLUSION</b>It could be concluded that p38 MAPK plays an important role in the brain ischemic tolerance induced by LIP.</p>

Effect of exogenous hydrogen sulfide on polymorphonuclear neutrophil accumulation in acute lung injury rat induced by lipopolysaccharides and its mechanism / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To study the effects of sodium hydrosulfide (NaHS), hydrogen sulfide (H2S) donor, on LPS-induced polymorphonuclear neutrophil (PMN) accumulation and its mechanism.</p><p><b>METHODS</b>The animal model of acute lung injury (ALI) caused by intravenous injection of lipopolysaccharides (LPS). Adult male Spraguce-Dawley (SD) rats were randomly divided into four groups (n = 8 - 12 per group): Control group (0.5 ml/kg normal saline i.v.), LPS-treated group (1 mg/kg, i.v.), LPS plus NaHS (1 mg/kg i.v. and 28 micromol/kg i.p., respectively) and NaHS group (28 micromol/kg i.p.). Animals were sacrificed at 6 h after agent administration. Morphological changes of lung tissues were observed and polymorphonuclear neutrophil (PMN) number in alveolar septum was tested. The apoptosis of PMN in the bronchoalveolar lavage fluid (BALF) was examined with in situ TdT-mediated dUTP end labeling (TUNEL). Intercellular adhesion factor-1 (ICAM-1) and nuclear factor-kappaB (NF-kappaB) expressions in the lung tissue were analyzed by Western Blot.</p><p><b>RESULTS</b>The results showed that bleeding, edema, PMN accumulation and other pathological signs in the lung tissue emerged after LPS injection. Compared to control rats, the LPS-treated rats had increased PMN number, decreased PMN apoptotic percentages, and increased expressions of ICAM-1 and NF-kappaB. Administration of NaHS into LPS-treated rats reduced the PMN number and expressions of ICAM-1 and NF-kappaB but increased PMN apoptotic percentages. In addition, NaHS alleviated the degree of ALI. There were no significant differences of the above indicators between NaHS-treated rats and control rats.</p><p><b>CONCLUSION</b>NaHS can reduce the PMN accumulation in the lung, and its mechanism is related to down-regulation expression of ICAM-1 and promotion of PMN apoptosis induced by inhibition of NF-kappaB pathway.</p>

Role of polymorphonuclear neutrophil in exogenous hydrogen sulfide attenuating endotoxin-induced acute lung injury / 生理学报

The animal model of acute lung injury (ALI) caused by intravenous injection of lipopolysaccharides (LPS) and cultured human peripheral blood polymorphonuclear neutrophil (PMN) were used to study the effects of sodium hydrosulfide (NaHS), hydrogen sulfide (H2S) donor, on LPS-induced PMN accumulation, microvascular permeability and PMN apoptosis. Control group, NaHS group, LPS group and LPS + NaHS group were established both in in vivo and in vitro studies. Microvascular permeability, PMN accumulation in lung and apoptosis of PMN were detected. The results showed that: (1) In in vivo study, PMN accumulation in lung, the protein content in bronchoalveolar lavage fluid (BALF) and the Evans blue dye in lung tissue of LPS group were markedly higher than those of both sham operation group and LPS + NaHS group (P<0.05, P<0.01); (2) In in vitro study, the apoptotic rates of PMN in LPS group and NaHS group were significantly higher than that in control group (P<0.01), while compared with LPS group, LPS + NaHS group showed significantly higher apoptotic rate (P<0.01). These results suggest that NaHS attenuates LPS-induced microvascular permeability and alleviates ALI. PMN apoptosis induced by NaHS is possibly one of the potential mechanisms underlying the decrease of PMN accumulation in lung tissue.

Ameliorative effects of exogenous sulfur dioxide on lipopolysaccharide-induced acute lung injury in rats / 生理学报

To investigate the influence of sulfur dioxide (SO₂) on lipopolysaccharide (LPS)-induced acute lung injury (ALI), we examined the influence of exogenous SO₂ on pulmonary tissue inflammatory response. A rat model of ALI induced by intravenous (IV) injection of LPS was developed. Male Sprague-Dawley (SD) rats were divided into four groups randomly: control group, LPS group, LPS plus SO₂ group (IV injection of 0.5 mL Na₂SO₃/NaHSO₃ 10 min before LPS administration) and SO₂ group (only given Na₂SO₃/NaHSO₃). Animals were sacrificed 6 h after agent administration. Lung weight/body weight ratio (LW/BW) was measured and calculated. Morphological changes of lung tissues were observed. The number of polymorphonuclear neutrophil (PMN) in the bronchoalveolar lavage fluid (BALF), intercellular adhesion factor-1 (ICAM-1) expression in the lung tissue and IL-1, IL-6 and IL-10 levels in the serum were tested. The results showed that, compared to control rats, the LPS-treated rats had severe injuries of lung tissues and an increased LW/BW, increased index of quantitative assessment (IQA) score, increased PMN number in the BALF, increased ICAM-1 expression in the lung tissue and increased IL-1, IL-6 and IL-10 levels in the serum 6 h after LPS injection. Administration of the SO₂ donor, Na₂SO/₃NaHSO₃, into LPS-treated rats reduced the LW/BW, PMN number and ICAM-1 expression, and alleviated the degree of ALI (measured by the IQA score). In addition, Na₂SO₃/NaHSO₃ decreased IL-1 and IL-6 levels, but increased IL-10 level in the serum. There were no significant differences in the above indexes between SO₂-treated rats and control rats. These results suggest that exogenous SO₂ could inhibit the pulmonary tissue inflammatory response in rats with LPS-induced ALI.

Intracerebroventricular administration of adenosine A1 receptor antisense oligodeoxynucleotide inhibites the neuroprotective effect of the cerebral ischemic preconditioning in rats / 中国应用生理学杂志

<p><b>AIM</b>To further explore the role of adenosine A1 receptor in the neuroprotective effect of cerebral ischemic preconditioning, the present study was undertaken to observe the effect of inhibiting expression of adenosine Al receptor with adenosine A1 receptor antisense oligodeoxynucleotide (ARA1 As-ODN) on the neuroprotective effect of cerebral ischemic preconditioning against delayed neuronal death (DND) normally induced by lethal brain ischemia.</p><p><b>METHOD</b>The rat 4-vessel occlusion global cerebral ischemic model was used. Forty-eight male Wistar rats with permanent occlusion of the bilateral vertebral arteries were divided into 8 groups: Sham, CIP, brain ischemic insult, CIP + brain ischemic insult, Distilled water + CIP + brain ischemic insult, ARA1 As-ODN, ARA1 As-ODN +CIP, ARA1 As-ODN+ CIP + brain ischemic insult(two doses of 10 nmol/5 microl and 20 nmol/5 microl were used) groups. ARA1 As-ODN was dissolved in distilled water and injected into the right lateral cerebral ventricle. To illustrate the profile of DND, histological grade (HG) and neuronal density (ND) in the CA1 region of the hippocampus were examined 7 d after the sham operation or the last time of ischemia under thionin staining.</p><p><b>RESULTS</b>The HG and ND in CIP group were similar to those in sham group. Brain ischemic insult induced obvious DND as represented with the increase in HG and decrease in ND significantly (P < 0.05 vs. sham and CIP groups). In CIP + ischemic insult group,no obvious DND was observed,which indicated that CIP protected pyramidal neurons against the ischemic insult.While the administration of ARA1 As-ODN in ARA1 As-ODN + CIP + brain ischemic insult group caused obvious increase in HG and decrease in ND compared with CIP + brain ischemic insult group (P < 0.05) in a dose dependent manner,which indicated that the neuroprotective effect of CIP against DND of hippocampal pyramidal neurons normally induced by ischemic insult was inhibited by the administration of ARA1 As-ODN.</p><p><b>CONCLUSION</b>The results further demonstrate the association of up-regulation of adenosine A1 receptors with the induction of CIP-mediated BIT.</p>

Role of endogenous hydrogen sulfide in pulmonary hypertension induced by lipopolysaccharide / 生理学报

The purpose of the present study was to explore the role of endogenous hydrogen sulfide (H2S) in pulmonary arterial hypertension induced by endotoxin. Adult male Sprague-Dawley (SD) rats were randomly divided into four groups: Control group (0.5 mL/kg body weight of normal saline, i.v.), lipopolysaccharide (LPS)-treated group (5 mg/kg body weight of LPS, i.v.), LPS + NaHS (5 mg/kg body weight of LPS, i.v., and 28 μmol/kg body weight of NaHS, i.p.) and LPS + PPG group (5 mg/kg body weight of LPS, i.v., and 30 μmol/kg body weight of PPG, i.p.). Rats were anesthetized with 20% urethane (1 g/kg body weight, i.p.). A polyethylene catheter was inserted into the pulmonary artery through the right external jugular vein to measure the mean pulmonary arterial pressure (mPAP) for 7 h, and then the pulmonary artery was isolated rapidly by the method described previously. Pulmonary arterial activity was detected. H2S concentration and cystathionine γ-lyase (CSE) activity in pulmonary artery tissues were determined by biochemical method. CSE mRNA expression was detected by competitive reverse transcriptase-polymerase chain reaction (RT-PCR). Compared with control, LPS significantly increased mPAP [(1.82±0.29) kPa vs (1.43±0.26) kPa, P<0.01], decreased H2S production [(26.33±7.84) vs (42.92±8.73) pmol/g wet tissue per minute, P<0.01), and reduced endothelium-dependent relaxation response [(75.72±7.22)% vs (86.40±4.40) %, P<0.01) induced by ACh (1×10(-6) mol/L). These effects were partly reversed by co-administration of NaHS and enhanced by co-administration of PPG. Both CSE activity and CSE mRNA expression were consistent with H2S production. It is suggested that the inhibitory effect of LPS on endothelium-dependent relaxation results in pulmonary hypertension, which might be mediated through H(2)S.

Antisense oligodeoxynucleotides of glial glutamate transporter-1 inhibits the neuro-protection of cerebral ischemic preconditioning in rats / 生理学报

The present study was undertaken to investigate the role of glial glutamate transporter-1 (GLT-1) in the brain ischemic tolerance induced by cerebral ischemic preconditioning (CIP) by observing the effect of GLT-1 antisense oligodeoxynucleotides (AS-ODNs) on the neuro-protection of CIP against brain ischemic insult in rats. Wistar rats with permanently occluded bilateral vertebral arteries were randomly assigned to 7 groups: (1) Sham group: the bilateral common carotid arteries (BCCA) were separated, but without occluding the blood flow; (2) CIP group: the BCCA were clamped for 3 min; (3) Brain ischemic insult group: the BCCA were clamped for 8 min; (4) CIP+brain ischemic insult group: 3 min CIP was preformed 2 d prior to 8 min ischemic insult; (5) Double distilled water group: 5 muL double distilled water was injected into the right lateral cerebral ventricle 12 h before, 12 h and 36 h after the BCCA was separated (but without occluding the blood flow), respectively; (6) AS-ODNs group: 5 microL AS-ODNs solution was injected into the right lateral cerebral ventricle 12 h before, 12 h and 36 h after the BCCA was separated (but without occluding the blood flow), respectively. This group was further divided into 9 nmol and 18 nmol subgroups according to the doses of AS-ODNs; (7) AS-ODNs+CIP+brain ischemic insult group: 5 microL AS-ODNs solution was injected into the right lateral cerebral ventricle 12 h before, 12 h and 36 h after CIP, respectively. This group was also further divided into 9 nmol and 18 nmol subgroups according to the doses of AS-ODNs. The other treatments were the same as those in CIP+brain ischemic insult group. The effect of the AS-ODNs on the expression of GLT-1 was assayed by using Western blot analysis. The profile of delayed neuronal death (DND) of pyramidal neurons in the CA1 hippocampus was evaluated by using thionin staining under light microscope by determining the neuronal density (ND) and histological grade (HG). Western blot analysis showed that AS-ODNs injected into the lateral cerebroventricle inhibited the expression of GLT-1 in the CA1 hippocampus in a dose-dependent manner. Neuropathological evaluation showed that there was no apparent DND in sham and CIP groups. Obvious DND of pyramidal neurons was found in brain ischemic insult group, which was represented by an increase in HG and a decrease in ND. CIP effectively protected the pyramidal neurons in the CA1 hippocampus against DND normally induced by ischemic insult, which indicating that CIP induced ischemic tolerance on the pyramidal neurons in the CA1 hippocampus. However, the injection of AS-ODNs into the lateral cerebroventricle blocked the neuro-protection of CIP against DND induced by brain ischemic insult. These results further proved the role of GLT-1 in the brain ischemic tolerance induced by CIP in rats.

The protective function of puerarin to the injury of the lung and its mechanisms during diabetes / 中国应用生理学杂志

<p><b>AIM</b>To evaluate the roles of puerarin in alleviating the STZ-induced lung injury.</p><p><b>METHODS</b>DM model was established by streptozotocin (STZ) intraperitoneal injection to study the injury mechanisms of the lung. SD rats were divided randomly into control group (C group), diabetes group (DM group), diabetes + puerarin group (DM + Pur group). The blood glucose and weight were observed and recorded before and the 20 th, 40 th, 60 thd after administration of saline, STS, STZ+ Pur. Contents of NO and malondialdehyde (MDA) and activity of superoxide dismutase (SOD) were measured in lung tissues. Light microscope (LM), transmission electron microscope (TEM) and immunohistochemical analysis were also used.</p><p><b>RESULTS</b>(1) Compared with control group, the contents of NO and MDA were increased significantly (P < 0.01), while the activity of SOD reduced (P < 0.05). Compared with DM group, treatment with puerarin inhibited the increase of NO level (P < 0.01), and MDA content began to decline from 40 days after the model was established (P < 0.01), and inhibited the decrease of SOD activity induced by DM (P < 0.01). (2) LM and TEM results showed that alveolar and capillary basement membrane became thick, the number of tiny villus decreased markedly, the quantity of osmiophilic multilamellar body reduced remarkably, hyperplasia was shown in collgen fibre. Puerarin could alleviate above injuries induced by DM. (3) Immunohistochemical staining results showed that mild brown positive stain of NT could be seen in protoplasm of lung tissues. STZ administration induced the expression of NT in the protoplasm of cells, and led to stronger positive signals of NT than that of control group. Treatment with puerarin weakened the positive stain of NT.</p><p><b>CONCLUSION</b>(1) DM induced by STZ leads to a significant and sustained increase in blood glucose and obvious lung injury, which may be associated with the overproduction of free radicals. (2) The pathway of NO/ONOO- is one of the injury mechanisms of the lung tissues cells. (3) Puerarin suppresses the expression of NT and elevates the activity of SOD. Thereby, resulting in the reduces of the production of free radicals, which may be one of the mechanisms of its anti-oxidative-injuries.</p>

The prior occlusion of bilateral vertebral arteries during producing global cerebral ischemic damage model may play a protective role as preconditioning / 中国应用生理学杂志

<p><b>AIM</b>To study the effect of different intervals between occlusions of vertebral arteries and bilateral common carotid arteries on the Pulsinelli 4-vessel occlusion global cerebral ischemic model, and the features of ischemia of the brainstem and hippocampus induced by occulusion of bilateral common carotid arteries under the condition of occlusion of unilateral vertebral artery.</p><p><b>METHODS</b>Eighty four adult male Wistar rats were divided into 4 groups randomly: control group, bilateral vertebral artery occluding group, global brain ischemic insult group, and unilateral vertebral artery occluding plus bilateral common carotid arteries occluding group. In the global brain ischemic insult group, rats were further divided into 24 h, 48 h, and 72 h interval subgroups according to the interval between the occlusion of the vertebral arteries and bilateral common carotid arteries. The responses including enlarging of pupils and the light reflex during the brain ischemia were observed. The duration of right reflex disappearing, the general state, and the delayed neuronal death (DND) of pyramidal neurons in the CA1 hippocampus of the rats after the brain ischemia were also observed.</p><p><b>RESULTS</b>Among the global brain ischemic insult group, both the responses and DND were more severe in 72 h interval subgroup than those in 24 h and 48 h interval subgroups. There was no significant difference between 24 h and 48 h interval subgroups. When the bilateral common carotid arteries were occluded under the condition of occlusion of unilateral vertebral artery, severe DND was observed in the CA1 hippocampus ipsilateral to the occluding vertebral artery, but no significant DND was observed in the contralateral CA1 hippocampus.</p><p><b>CONCLUSION</b>The results suggested that the prior occlusion of the bilateral vertebral arteries during producing Pulsinelli 4-vessel occlusion global cerebral ischemic model might be a cerebral ischemic preconditioning that could protect to some extent pyramidal neurons of the hippocampus against severe ischemic insult induced by occlusion of bilateral common carotid arteries within 48 h. Moreover, There is ipsilateral predominance of blood perfusion from one side of vertebral artery to the brainstem and hippocampus, although there was Willis artery circle in rats.</p>

Relationship between hydrogen sulfide and myocardial damage in endotoxemic rats / 生理学报

To investigate the changes and role of hydrogen sulfide (H2S) in myocardial damage in endotoxemic rats, a rat model of endotoxemia induced by injection of lipopolysaccharide (LPS) was developed. Male Wistar rats were divided into four groups: control group, LPS group, LPS + propargylglycine (PPG, a metabolic enzyme inhibitor of H2S) group and LPS + NaHS (H2S donor) group. The mean arterial pressure (MAP) of rats within 4 h was observed, TNF-alpha and H2S contents in plasma, TNF-alpha and H2S contents, lactate dehydrogenase (LDH) and myeloperoxidase (MPO) activity in cardiac muscles were determined. The morphological structure of cardiac muscle was observed. Administration of LPS caused a sustained fall in MAP within 4 h, and significant increases in TNF-alpha and H2S contents in plasma (P<0.05). Plasmic H2S content was negatively correlated with MAP (r = -0.936, -0.913 and -0.908 at 1, 2 and 4 h, respectively, P<0.05). LPS also induced increases in TNF-alpha and H2S contents, LDH and MPO activity in cardiac muscles and myocardial damage. Treatment with PPG reduced the increases in TNF-alpha and H2S contents in plasma, TNF-alpha and H2S contents, LDH and MPO activity in cardiac muscles, ameliorated the hypotensive effect and myocardial damage caused by LPS administration (P<0.05). However, treatment with NaHS increased TNF-alpha and H2S contents in plasma, TNF-alpha and H2S contents, LDH and MPO activity in cardiac muscles, and aggravated the hypotensive action and tissue injuries caused by LPS administration (P<0.05). It is suggested that hypotension and myocardial damage in endotoxemic rats are partly induced by increase in H2S content.