AIM: To investigate the effect of emodin on small intestinal peristalsis of mice and to explore its relevant mechanisms.METHODS: The effect of emodin on small intestinal peristalsis of mice was observed by charcoal po...AIM: To investigate the effect of emodin on small intestinal peristalsis of mice and to explore its relevant mechanisms.METHODS: The effect of emodin on small intestinal peristalsis of mice was observed by charcoal powder propelling test of small intestine. The contents of motilin and somatostatin in small intestine of mice were determinated by radioimmunoassay. The electrical potential difference (PD) related to Na+ and glucose transport was measured across the wall of reverted intestinal sacs. Na+-K+-ATPase activity of small intestinal mucosa was measured by spectroscopic analysis.RESULTS: Different dosages of emodin can improve small intestinal peristalsis of mice. Emodin increased the content of motilin, while reduced the content of somatostatin in small intestine of mice significantly. Emodin 0.2, 0.4, 0.8, and 1.6 g/L decreased PD when there was glucose. However, emodin had little effect when glucose was free. The Na+-K+-ATPase activity of small intestinal mucosa of mice in emodin groups was inhibited obviously. CONCLUSION: Emodin can enhance the function of small intestinal peristalsis of mice by mechanisms of promoting secretion of motilin, lowering the content of somatostatin and inhibiting Na+-K+-ATPase activity of small intestinal mucosa.展开更多
Using mice infected with coxsackie B-3 virus (CVB3) as a viral myocarditis model, we observed the inhibitory effect of Astragalus membranaceus (AM) on CVB3-RNA replication in myocardial tissue of mice by RNA-RNA in si...Using mice infected with coxsackie B-3 virus (CVB3) as a viral myocarditis model, we observed the inhibitory effect of Astragalus membranaceus (AM) on CVB3-RNA replication in myocardial tissue of mice by RNA-RNA in situ hybridization with negative-strand RNA Probes labelled with ￣(35)S and quantitative imaging analysis of positive signals. The mechanism of its effect on CVB3-RNA replication has been investigated by detection of beta-interferon (β-IFN) as well. Results showed that the copy numbers of CVB3-RNA as well as the histologic scores (necrosis) in myocardial tissues of infected-AM treated mice were significantly lower than those in infected and normal saline treated mice, suggesting that AM could inhibit the replication of CVB3-RVA,but its effect on CVB3-RNA replication had no correlation with induction of β-IFN.展开更多
In order to investigate the mechanisms of acute cerebral ischemia, and to look for effective drugs on cerebral resuscitation, we made a model of acute complete global brain ischemia, reperfusion and resuscitation on r...In order to investigate the mechanisms of acute cerebral ischemia, and to look for effective drugs on cerebral resuscitation, we made a model of acute complete global brain ischemia, reperfusion and resuscitation on rats according to Garavilla's method.Our results showed that the event of cerebral ischemia and reperfusion injury could resuh in the increase of total brain calcium content, and anisodamine has the same reducing brain calcium contents as diltiazem's, while improving neurological outcome and alleviating injury to neurons.展开更多
Orphanin FQ（OFQ） or nociceptin is a novel neuropeptide consisting of 17 amino acids. This peptide has a primary structure reminiscent of that of opioid peptide but exhibits an opposite effect to make animals hyperre...Orphanin FQ（OFQ） or nociceptin is a novel neuropeptide consisting of 17 amino acids. This peptide has a primary structure reminiscent of that of opioid peptide but exhibits an opposite effect to make animals hyperreactive. The effect of this new peptide on cardiovascular function are not completely known. The present study was conducted to investigate the effect of intravenous bolus injection of orphanin FQ on mean arterial blood presure （MABP） in conscious stroke-prone spontaneously hypertensive rats (SHRsp). Adult male SHRsp and Wistar normotensive rats （250～300 g body weight, 2. 5～3 months old） were used in this study. The MABP was measured in the conscious state by a tail-cuff method. In SHRsp model, intravenous bolus injection of orphanin FQ or Tyr1-orphanin FQ （0. 5 mg/kg） induced a prolonged and marked reduc- tion in MABP. The maximum changes in MABP were -30. 2±4. 2 mmHg by orphanin FQ and -28. 2± 4. 7 mmHg by Tyr1-orphanin FQ at 10 min after administration,and this effect lasted over 30 min. The Phe1→Tyr substitution in orphanin FQ was found to retain almost fully hypotensive activity. Pretreatment of SHRsp with naloxone-HCI（60 μg/kg）, 5 min before the injection of orphanin FQ, did not block the hy- potensive effect of orphanin FQ. Therefore, opioid receptors could not account for the hypotensive effect of orphanin FQ in SHRsp. In Wistar rats, intravenous bolus injection of the same dose of orphanin FQ did not cause a change in MABP. These observations suggest that orphanin FQ is a novel hypotensive peptide and may have some role in the regulation of blood pressure in SHRsp, rather than in normotensive rats. The ex-act underlying mechanisms are waiting to be clarified.展开更多
Objective.To investigate the protective effects of melatonin(MT )on cardiomyocytes against the ox-idative injury induced by H 2 O 2 .Methods.Ventricular myocytes were isolated from neonatal rats and cultured for3～5da...Objective.To investigate the protective effects of melatonin(MT )on cardiomyocytes against the ox-idative injury induced by H 2 O 2 .Methods.Ventricular myocytes were isolated from neonatal rats and cultured for3～5days.Cells were divided into4groups:control group,H 2 O 2 (100μmol/L H 2 O 2 )group,MT group(100μmol/L MT )and MT preconditioning group(100μmol/L MT+100μmol/L H 2 O 2 ).The fluorescent probe,DCFH?DA,was used to detect intracellular levels of reactive oxygen species(ROS)and another fluorescent probe,Fluo-3?AM,was used to detect[Ca 2+ ] i by using a laser scanning confocal microscopy(LSCM).The malondi-aldehyde(MDA)content in cardiomyocytes was determined by measuring thiobarbituric acid?reactive sub-stances to monitor lipid peroxidation.The activity of cytoplasmic enzyme lactate dehydrogenase(LDH)that was released into the culture media was assayed to indicate alternation in the integrity of the cellular membrane.Trypan blue exclusion was used to detect the cell viability.Results.Compared with the control group,intracellular ROS,[Ca 2+ ] i ,MDA content ,LDH leakage and cell death were significantly elevated when cells were treated by100μmol/L H 2 O 2 for60minutes(P<0.01).However,those changes were significantly attenuated in MT preconditioning group.Conclusion.MT has very good antioxidant effect and can protect the cardiomyocytes against H 2 O 2 -in-duced injury.展开更多
Objective. To determine the effects of losartan and captopril treatment on ventricular remodeling and function after myocardial infarction in rats. Methods. Thirty-two rats with MI induced by coronary ligation after s...Objective. To determine the effects of losartan and captopril treatment on ventricular remodeling and function after myocardial infarction in rats. Methods. Thirty-two rats with MI induced by coronary ligation after seven days were divided into four groups randomly and treated with captopril(2 g. liter-1, group A), losartan(10 mg. kg-1. d-1, group B), losartan(30 mg. kg-1. d-1,group C) and placebo (no drug, group D) for six weeks, respectively. Shamoperated rats(group E)served as controls. Echocardiography was performed at 1 and 7 weeks after MI, re- spectively. Results. Compared with the results before treatment,both LV end-diastolic internal diameter and volume decreased significantly and the thickened Posterior wall was reversed in group A, B and C; the peak early filling velocity decreased whereas the peak velocity was increased in these three groups. There are no significant difference among the three treated groups. However,LV end-diastolic internal diameter and the E/A were still increased,whereas the thickness of anterior wall and the peak velocity of LV outflow were decreased in group A,B,and C after treatment comparing with group E. Conclusion. Both angiotensin converting enzyme inhibitor and angiotensin II receptor antagonist can prevent the ventricular remodeling and improve the ventricular function.展开更多
Objectives.To study the expression of TNF α mRNA and the effect of somatostatin on the expression of TNF α mRNA in multiorgans of rats with acute hemorrhagic necrotic pancreatitis(AHNP). Methods.AHNP in the rat was ...Objectives.To study the expression of TNF α mRNA and the effect of somatostatin on the expression of TNF α mRNA in multiorgans of rats with acute hemorrhagic necrotic pancreatitis(AHNP). Methods.AHNP in the rat was induced by retrograde injection of 5% sodium taurocholate into the bile-pancreatic duct. Somatostatin octapeptide (SS-OP) (2μg/kg)was injected into the femoral vein imme- diately in rats of the treatment group after inductive AHNP. Rats of the sham operative group received in- jection of saline. Sixty animals of the AHNP and sham operative groups at the designated time(0. 2h, 0. 5 h, 2h, 4h, 8h, after the operation,six animals at each time point)and tweleve animals of treatment group at 4h after the operation were sacrificed for samples of pancreas, liver and lung. The expressions of TNF α mRNA within the pancreas, liver and lung were established by RT－PCR. Results. TNF α mRNA became detectable in the pancreas as early as 0. 2h after inductive AHNP, while it was undetectable in other organs until 0. 5h. Expression of TNF α mRNA in each tissue increased continuously and reached a peak at 4h,demonstrating a significant difference compared with that at 0. 5h and 8h. Expressions of TNF α mRNA from pancreas, liver and lung were decreased 50-80% in the treat- ment group, the pancreatic necrosis was also attenuated dramatically. Conclusion. TNF α mRNA was detectable in pancreas,liver and lung tissues at the early stage of AH- NP.SS-OP can significantly inhibit the expression of TNF α mRNA and attenuate the pancreatic necrosis. We feel that this may be an important mechanism of SS-OP in the treatment of AHNP.展开更多
Objective: To study the therapeutic effect of nimodipine on experimental brain injury. Methods: Experimental and control rabbits were subjected to a closed head injury. In one group nimodipine was given intravenously ...Objective: To study the therapeutic effect of nimodipine on experimental brain injury. Methods: Experimental and control rabbits were subjected to a closed head injury. In one group nimodipine was given intravenously and the effect evaluated by electron microscopy, brain water content, calcium levels, transcranial Doppler, and intracranial pressure monitoring. Results: In rabbits treated with nimodipine the level of neuronal cytosolic free calcium was markedly decreased. There were less cellular damage and less spasm of the middle cerebral artery seen on electron microscopy. No difference regarding intracranial pressure changes between the two groups was noted. Conclusions: Nimodipine has a protective action on brain injury by blocking a series of pathological reactions induced by neuronal calcium overload, and by reducing the spasm of brain vessels and improving cerebral blood flow.展开更多
文摘AIM: To investigate the effect of emodin on small intestinal peristalsis of mice and to explore its relevant mechanisms.METHODS: The effect of emodin on small intestinal peristalsis of mice was observed by charcoal powder propelling test of small intestine. The contents of motilin and somatostatin in small intestine of mice were determinated by radioimmunoassay. The electrical potential difference (PD) related to Na+ and glucose transport was measured across the wall of reverted intestinal sacs. Na+-K+-ATPase activity of small intestinal mucosa was measured by spectroscopic analysis.RESULTS: Different dosages of emodin can improve small intestinal peristalsis of mice. Emodin increased the content of motilin, while reduced the content of somatostatin in small intestine of mice significantly. Emodin 0.2, 0.4, 0.8, and 1.6 g/L decreased PD when there was glucose. However, emodin had little effect when glucose was free. The Na+-K+-ATPase activity of small intestinal mucosa of mice in emodin groups was inhibited obviously. CONCLUSION: Emodin can enhance the function of small intestinal peristalsis of mice by mechanisms of promoting secretion of motilin, lowering the content of somatostatin and inhibiting Na+-K+-ATPase activity of small intestinal mucosa.
文摘Using mice infected with coxsackie B-3 virus (CVB3) as a viral myocarditis model, we observed the inhibitory effect of Astragalus membranaceus (AM) on CVB3-RNA replication in myocardial tissue of mice by RNA-RNA in situ hybridization with negative-strand RNA Probes labelled with ￣(35)S and quantitative imaging analysis of positive signals. The mechanism of its effect on CVB3-RNA replication has been investigated by detection of beta-interferon (β-IFN) as well. Results showed that the copy numbers of CVB3-RNA as well as the histologic scores (necrosis) in myocardial tissues of infected-AM treated mice were significantly lower than those in infected and normal saline treated mice, suggesting that AM could inhibit the replication of CVB3-RVA,but its effect on CVB3-RNA replication had no correlation with induction of β-IFN.
文摘In order to investigate the mechanisms of acute cerebral ischemia, and to look for effective drugs on cerebral resuscitation, we made a model of acute complete global brain ischemia, reperfusion and resuscitation on rats according to Garavilla's method.Our results showed that the event of cerebral ischemia and reperfusion injury could resuh in the increase of total brain calcium content, and anisodamine has the same reducing brain calcium contents as diltiazem's, while improving neurological outcome and alleviating injury to neurons.
文摘Orphanin FQ（OFQ） or nociceptin is a novel neuropeptide consisting of 17 amino acids. This peptide has a primary structure reminiscent of that of opioid peptide but exhibits an opposite effect to make animals hyperreactive. The effect of this new peptide on cardiovascular function are not completely known. The present study was conducted to investigate the effect of intravenous bolus injection of orphanin FQ on mean arterial blood presure （MABP） in conscious stroke-prone spontaneously hypertensive rats (SHRsp). Adult male SHRsp and Wistar normotensive rats （250～300 g body weight, 2. 5～3 months old） were used in this study. The MABP was measured in the conscious state by a tail-cuff method. In SHRsp model, intravenous bolus injection of orphanin FQ or Tyr1-orphanin FQ （0. 5 mg/kg） induced a prolonged and marked reduc- tion in MABP. The maximum changes in MABP were -30. 2±4. 2 mmHg by orphanin FQ and -28. 2± 4. 7 mmHg by Tyr1-orphanin FQ at 10 min after administration,and this effect lasted over 30 min. The Phe1→Tyr substitution in orphanin FQ was found to retain almost fully hypotensive activity. Pretreatment of SHRsp with naloxone-HCI（60 μg/kg）, 5 min before the injection of orphanin FQ, did not block the hy- potensive effect of orphanin FQ. Therefore, opioid receptors could not account for the hypotensive effect of orphanin FQ in SHRsp. In Wistar rats, intravenous bolus injection of the same dose of orphanin FQ did not cause a change in MABP. These observations suggest that orphanin FQ is a novel hypotensive peptide and may have some role in the regulation of blood pressure in SHRsp, rather than in normotensive rats. The ex-act underlying mechanisms are waiting to be clarified.
文摘Objective.To investigate the protective effects of melatonin(MT )on cardiomyocytes against the ox-idative injury induced by H 2 O 2 .Methods.Ventricular myocytes were isolated from neonatal rats and cultured for3～5days.Cells were divided into4groups:control group,H 2 O 2 (100μmol/L H 2 O 2 )group,MT group(100μmol/L MT )and MT preconditioning group(100μmol/L MT+100μmol/L H 2 O 2 ).The fluorescent probe,DCFH?DA,was used to detect intracellular levels of reactive oxygen species(ROS)and another fluorescent probe,Fluo-3?AM,was used to detect[Ca 2+ ] i by using a laser scanning confocal microscopy(LSCM).The malondi-aldehyde(MDA)content in cardiomyocytes was determined by measuring thiobarbituric acid?reactive sub-stances to monitor lipid peroxidation.The activity of cytoplasmic enzyme lactate dehydrogenase(LDH)that was released into the culture media was assayed to indicate alternation in the integrity of the cellular membrane.Trypan blue exclusion was used to detect the cell viability.Results.Compared with the control group,intracellular ROS,[Ca 2+ ] i ,MDA content ,LDH leakage and cell death were significantly elevated when cells were treated by100μmol/L H 2 O 2 for60minutes(P<0.01).However,those changes were significantly attenuated in MT preconditioning group.Conclusion.MT has very good antioxidant effect and can protect the cardiomyocytes against H 2 O 2 -in-duced injury.
基金This study was supported by National Natural Science Foundation of China (39470313)
文摘Objective. To determine the effects of losartan and captopril treatment on ventricular remodeling and function after myocardial infarction in rats. Methods. Thirty-two rats with MI induced by coronary ligation after seven days were divided into four groups randomly and treated with captopril(2 g. liter-1, group A), losartan(10 mg. kg-1. d-1, group B), losartan(30 mg. kg-1. d-1,group C) and placebo (no drug, group D) for six weeks, respectively. Shamoperated rats(group E)served as controls. Echocardiography was performed at 1 and 7 weeks after MI, re- spectively. Results. Compared with the results before treatment,both LV end-diastolic internal diameter and volume decreased significantly and the thickened Posterior wall was reversed in group A, B and C; the peak early filling velocity decreased whereas the peak velocity was increased in these three groups. There are no significant difference among the three treated groups. However,LV end-diastolic internal diameter and the E/A were still increased,whereas the thickness of anterior wall and the peak velocity of LV outflow were decreased in group A,B,and C after treatment comparing with group E. Conclusion. Both angiotensin converting enzyme inhibitor and angiotensin II receptor antagonist can prevent the ventricular remodeling and improve the ventricular function.
文摘Objectives.To study the expression of TNF α mRNA and the effect of somatostatin on the expression of TNF α mRNA in multiorgans of rats with acute hemorrhagic necrotic pancreatitis(AHNP). Methods.AHNP in the rat was induced by retrograde injection of 5% sodium taurocholate into the bile-pancreatic duct. Somatostatin octapeptide (SS-OP) (2μg/kg)was injected into the femoral vein imme- diately in rats of the treatment group after inductive AHNP. Rats of the sham operative group received in- jection of saline. Sixty animals of the AHNP and sham operative groups at the designated time(0. 2h, 0. 5 h, 2h, 4h, 8h, after the operation,six animals at each time point)and tweleve animals of treatment group at 4h after the operation were sacrificed for samples of pancreas, liver and lung. The expressions of TNF α mRNA within the pancreas, liver and lung were established by RT－PCR. Results. TNF α mRNA became detectable in the pancreas as early as 0. 2h after inductive AHNP, while it was undetectable in other organs until 0. 5h. Expression of TNF α mRNA in each tissue increased continuously and reached a peak at 4h,demonstrating a significant difference compared with that at 0. 5h and 8h. Expressions of TNF α mRNA from pancreas, liver and lung were decreased 50-80% in the treat- ment group, the pancreatic necrosis was also attenuated dramatically. Conclusion. TNF α mRNA was detectable in pancreas,liver and lung tissues at the early stage of AH- NP.SS-OP can significantly inhibit the expression of TNF α mRNA and attenuate the pancreatic necrosis. We feel that this may be an important mechanism of SS-OP in the treatment of AHNP.
文摘Objective: To study the therapeutic effect of nimodipine on experimental brain injury. Methods: Experimental and control rabbits were subjected to a closed head injury. In one group nimodipine was given intravenously and the effect evaluated by electron microscopy, brain water content, calcium levels, transcranial Doppler, and intracranial pressure monitoring. Results: In rabbits treated with nimodipine the level of neuronal cytosolic free calcium was markedly decreased. There were less cellular damage and less spasm of the middle cerebral artery seen on electron microscopy. No difference regarding intracranial pressure changes between the two groups was noted. Conclusions: Nimodipine has a protective action on brain injury by blocking a series of pathological reactions induced by neuronal calcium overload, and by reducing the spasm of brain vessels and improving cerebral blood flow.
