ABSTRACT
<p><b>OBJECTIVE</b>To assess complement-mediated myocardial injury on isolated guinea pig working hearts and cardioprotective effects of CD59.</p><p><b>METHODS</b>Using a modified Langendorff apparatus, isolated guinea-pig working hearts were perfused with a modified Krebs Henseleit buffer containing 3% heat-inactivated human plasma and zymosan (IPZ) (control) (n = 10), 3% normal human plasma and zymosan (NPZ) (n = 10), or 3% normal human plasma and zymosan and 1.5 microg/ml CD59 (NPZC) (n = 10), respectively. Epicardial electrocardiogram (ECG), cardiac output (CO), coronary arterial flow (CF), maximum left ventricular developed pressure (LVP(max)), maximum left ventricular developed pressure increase rate (+ dp/dt(max)), maximum left ventricular developed pressure decrease rate (- dp/dt(max)) and heart rate (HR) were recorded at 0, 15, 30, 45 and 60 min of treatment. After the experiment, immunohistochemical examination was performed to detect the presence of C3a or C5b-9 in the myocardium of the isolated hearts.</p><p><b>RESULTS</b>Compared the IPZ group, hearts treated with NPZ showed a slight depression on ST segments of epicardial ECG at 15 min, a significant elevation between 30 min to 60 min, a decrease in CF, CO, LVP(max), + dp/dt(max) and - dp/dt(max), and an increase in HR at 15 min. The observed alterations in CF, CO, LVP(max), + dp/dt(max) and - dp/dt(max) remained decreased, while the HR remained increased until the end of the protocol. The all above parameters of hearts treated with NPZC were similar to the control group (IPZ) at any given time. Immunohistochemical examination showed positive signals of C3a and C5b-9 in the myocardium of hearts treated with NPZ. C3a was positive in NPZC, and C3a and C5b-9 were negative in IPZ.</p><p><b>CONCLUSIONS</b>Activated human complements directly damage isolated guinea pig working hearts, and CD59 offers a significant protection against the injuries.</p>
Subject(s)
Animals , Male , CD59 Antigens , Pharmacology , Complement C3a , Metabolism , Complement Inactivator Proteins , Pharmacology , Electrocardiography , Guinea Pigs , Heart , Physiology , Immunohistochemistry , In Vitro Techniques , Myocardium , Metabolism , Pathology , Time FactorsABSTRACT
【Objective】To investigate the molecular mechanism of dopamine (DA)-induced apoptosis in cultured cerebellar granule neurons (CGNs) and the effect of muscarinic cholinergic receptor (mAChR) agonist carbachol on it.【Methods】The apoptosis of neurons was measured by phase-contrast microscopy,Hoechst 33258 nucleus staining and DNA fragmentation agarose gel electrophoresis.The neuronal viability was measured by fluorescein diacetate (FDA) staining.The activation of extracellular signal-regulated protein kinase (ERK) was determined by Western blot.【Results】Dopamine increases the phosphorylation of ERK and induces apoptosis in CGNs,which is blocked by both carbachol and PD 98059.The protective effect and the inhibiting ERK phosphorylation of carbachol were blocked by atropine.【Conclusion】DA-induced apoptosis in CGNs may be mediated by activation of ERK.Carbachol protects CGNs from DA-induced apoptosis by activating mAChR and subsequent inhibition of activation of ERK.
ABSTRACT
AIM: To study the reactions of human platelet to active complement and the effects of anti-CD59 on human platelet activation induced by complement. METHODS: By applying CVF to activate complement, the platelet aggregation and release reactions induced by activated complement with or without appling anti-CD59 with different doses to block the complement modulative protein CD59 in healthy individuals, were observed. RESULTS: CVF induced platelet release and significant and lasting metamorphosis in healthy individuals, but platelet aggregation was not observed. CVF-induced platelet metamorphosis showed positive linear correlation to lg concentration of CVF (r=0 970. P
ABSTRACT
Usually experiments done on isolated working heart preparation must be completed within 1 h, because of declining of cardiac functions after going beyond that limit reported by many authors. Our experiments on guinea pig showed that the viability time lasted at least 2 h. All measured indices of cardiac performance, namely LVP, dP/dtmax, MASP, HR, CF, AF, CO, LVPW, MVO2 and. working efficiency, remained stable within that period of time, .when PcO2 and PO2 of perfusing solution were adjusted at 4.7~7.3 kPa and over 67 kPa respectively, resulting in stability of pH value in 7.4 or so. Modification of the Krebs solution by devoid of phosphate and addition of pyruvate and EDTA may also be responsible for prolongation of the viability time. After such improvement, the preparation will give sufficient time to study the effect of drugs. Its use will be greatly widened.1 -10 mg/L cobra cardiotoxin increased CO, AF, LVEDP, MASP, LVP, dP/dtmax, decreased CF, and unchanged HR.MVO2 and working efficiency were insignificantly increased. These results obtained from this preparation were in accordance with that from other isolated cardiac preparations.
ABSTRACT
AIM To establish the model of exudative pleurisy induced by alternatively activating complement and to study protection of anti inflammatory drugs on it. METHODS Purified cobra venom factor (CVF) was injected into the pleura, and then exudate volumn, total leukocyte count, protein content and histamine concentration were determined. RESULTS CVF, injected into rat pleura at dose of 0 08～2 mg?kg -1 , induced exudative inflammation in dose dependent and time dependent manner. Both diphehydramine and isoprenaline reduced significantly exudate volume, total leukocyte count, protein content and histamine concentration, while indomethacin, dexamethasone and cyclophosphamide also reduced exudate volume, total leukocyte count and protein content, although they did change the release of histamine. DLF, one of the toxic components in cobra venom, potentiated CVF induced inflammation. CONCLUSION CVF can induce significantly exudative pleurisy sensitive to anti inflammatory agents. DLF has augmentation on CVF induced inflammation.