OBJECTIVETo explore the mitochondrial toxicities induced by zidovudine (AZT) and adefovir dipivoxil (ADV) antiviral drugs using a rat model system.

METHODSTwelve healthy Sprague-Dawley rats were randomly divided into three equal groups and treated by oral gavage with zidovudine (125 mg/kg/day), adefovir (40 mg/kg/day), or saline (equal volume) for 28 days. The rats' body weights were measured once a week, and blood was collected every two weeks for blood and biochemical tests. All animals were sacrificed at the end of treatment, and liver, kidney, skeletal muscle, and cardiac muscle were collected by necropsy. Mitochondria were isolated from the respective tissue samples, and the activities of respiratory chain complexes were measured. DNA was purified from each sample and the mitochondrial DNA (mtDNA) content was monitored by quantitative real time PCR. Mitochondrial morphology was analyzed under electron microscope.

RESULTSNo significant adverse effects, including body weight loss, abnormal blood or biochemistry, were observed in rats treated with AZT or ADV. The activities of mitochondrial cytochrome c oxidase in liver and cardiac muscle were slightly decreased in rats treated with AZT (liver: 9.44+/-3.09 vs. 17.8+/-12.38, P?=?0.21; cardiac muscle: 32.74+/-5.52 vs. 24.74+/-20.59, P?=?0.28; kidney: 4.42+/-1.53 vs. 14.45+/-13.75, P?=?0.18; skeletal muscle: 33.75+/-8.74 vs. 40.04+/-2.49, P?=?0.45). The mtDNA content was significantly decreased in cardiac muscle of AZT-treated rats (cardiac muscle: 0.15+/-0.13 vs. 0.32+/-0.42, P?=?0.85). The morphology of mitochondria in liver, kidney, skeletal muscle, and cardiac muscle was significantly altered in the AZT-treated rats and included disappearance of the outer membrane, severely damaged structure, and swollen or completely absent cristae. No obvious effects were noted in the ADV- or saline-treated rats.

CONCLUSIONSignificant adverse effects related to mitochondrial toxicity were observed in rats treated with AZT. The slightly decreased mtDNA content in ADV-treated rats may suggest that this antiviral drug can also cause mitochondrial toxic effects.

Adenine ; adverse effects ; analogs & derivatives ; Animals ; DNA, Mitochondrial ; drug effects ; Electron Transport Complex IV ; metabolism ; Female ; Kidney ; enzymology ; Liver ; enzymology ; Mitochondria ; drug effects ; metabolism ; Mitochondria, Heart ; drug effects ; Mitochondria, Liver ; drug effects ; Mitochondria, Muscle ; drug effects ; Muscle, Skeletal ; enzymology ; Myocardium ; enzymology ; Organophosphonates ; adverse effects ; Rats ; Rats, Sprague-Dawley ; Zidovudine ; adverse effects

OBJECTIVE: To find out the pathological change and the toxic mechanism of Chloranthus serratus Roem. et Schalt in mice. METHODS: Mice were intoxicated by oral administration with extracts of Chloranthus serratus Roem. et Schalt followed by pathological, serum biochemical, and coagulation mechanism examination. RESULTS: The LD50 in mice was 41.12 g/kg; All poisoned mice serum BUN and ALT increased markedly; Thrombocyte decreased and coagulation time increased; The organ index of liver, spleen and kidneys increased significantly; The cells of liver, kidney and heart were degeneration and necrosis, There were extensive hyperemia and hemorrhage in many organs. CONCLUSION The experiment suggests that the target organs were liver, kidney, heart and blood vessels; The toxic mechanism was the damage on the mitochondrional, endoplasmic reticulum and coagulation system.
Animals ; Biomarkers/blood* ; Dose-Response Relationship, Drug ; Endoplasmic Reticulum/drug effects* ; Female ; Forensic Pathology ; Kidney/pathology* ; Lethal Dose 50 ; Liver/pathology* ; Magnoliopsida/chemistry* ; Male ; Mice ; Mitochondria, Heart/drug effects* ; Mitochondria, Liver/drug effects* ; Myocardium/pathology* ; Plant Extracts/toxicity* ; Random Allocation

OBJECTIVETo investigate the effect of microtubule depolymerization on mitochondria damage in rat myocardiocytes early after hypoxia.

METHODSMyocardiocytes from Wistar rats were isolated according to routine procedure, and they were randomly divided into control group, depolymerization group (with treatment of 4 micromol/L colchicines in the culture medium), hypoxia group, hypoxia and depolymerization group (with treatment of 4 micromol/L colchicines in the culture medium combined with low oxygen tension). The changes in distribution of the mitochondria were examined with laser confocal microscopy, the morphology and the structure of mitochondria was observed by transmission electron microscope, the respiration control ratio (RCR) was determined by respirometer, and the content of adenosine triphosphate (ATP) in endochylema was detected with liquid chromatograph at 20, 30, 60 post-hypoxia minutes (PHM).

RESULTSIn control group, the mitochondria was in granular form, with regular arrangement, while mild changes were observed in depolymerization group. At 20, 30, and 60 PHM, the disarrangement in distribution and morphologic damage were aggravated in hypoxia depolymerization group, and the RCR (1.58 +/- 0.37, 1.51 +/- 0.32, 1.12 +/- 0.11, respectively) were evidently lower than those in hypoxia group (3.85 +/- 0.56, 2.98 +/- 0.44, 1.79 +/- 0.73, respectively, P < 0.01). The content of ATP showed the same tendency at the same time-points (419 +/- 83, 326 +/- 73, 295 +/- 58 ng/mg) compared with hypoxia depolymerization group [(475 +/- 68, 397 +/- 59, 336 +/- 67 ng/mg) in hypoxia group].

CONCLUSIONThe disarrangement in distribution of mitochondria, as well as the damage in mitochondrial structure, respiratory, function and energy metabolism, can be aggravated by microtubule depolymerization after hypoxia, which indicates that microtubule depolymerization plays an important role in the mitochondria damage.

Animals ; Cell Hypoxia ; Cells, Cultured ; Colchicine ; adverse effects ; Disease Models, Animal ; Hypoxia ; pathology ; Microtubules ; pathology ; Mitochondria, Heart ; drug effects ; pathology ; Random Allocation ; Rats ; Rats, Wistar

OBJECTIVETo investigate the influence of pinacidil preconditioning on the protection of the structure and respiratory function of injured myocardial mitochondria in scalded rats.

METHODSSeventy-five healthy Wistar rats, weighed 250 approximately 300 g, were randomly divided into three groups: i.e. control (n = 9, with intraperitoneal injection of 50 microg/kg isotonic saline), scald (n = 33, with 30% TBSA full thickness scald) and pre-conditioning (n = 33, with same extent of scald injury after intraperitoneal injection of 50 microg/kg pinacidil) groups. Mitochondrial ultrastructure was observed by transmission electron microscope. The mitochondrial respiratory function, the MDA content and the superoxide anion level were determined with corresponding methods.

RESULTSThe degree of injury to rat myocardial mitochondria in pre-conditioning group was less intensive than that in scald group (P < 0.05 or 0.01). The respiratory control rate in pre-conditioning group was obviously higher than that in scald group (P < 0.05), and the contents of MDA and superoxide anion in pre-conditioning group were markedly lower than those in scald group (P < 0.05 or 0.01), as evidenced by their contents at 3 post scalding hours (0.60 +/- 0.09 micromol/g and 0.127 +/- 0.020) were obviously lower than those in scald group (0.83 +/- 0.07 micromol/g and 0.169 +/- 0.015) (P < 0.01).

CONCLUSIONPinacidil preconditioning was beneficial in the protection of myocardial mitochondria in scalded rats, and it might be related to the pre-opening of potassium channel which was sensitive to mitochondrial ATP.

Animals ; Burns ; drug therapy ; metabolism ; pathology ; Cell Respiration ; drug effects ; Disease Models, Animal ; Mitochondria, Heart ; metabolism ; pathology ; Pinacidil ; therapeutic use ; Rats ; Rats, Wistar ; Superoxides ; analysis

OBJECTIVETo study pathological and therapeutical problems concerning myocardial cell mitochondria changes during myocardial cell hypertrophy by culturing rat primary myocardial cells.

METHODPrimary myocardial cells were seperated and cultured together with angiotensin II (Ang II) for 72 or 96 hours. The total protein content with the BCA method and the photography and measurement of cell diameter with inverted microscope reflected myocardial cell proliferation. The mitochondrial membrane potential (Delta Psi m) with fluorescence microscope, the mitochondrial single amine oxidase (MAO) activity with spectrophotometer, the mitochondrial cytochrome oxidase (COX) activity and the injury percentage of mitochondrial outer membrane with microplate reader and the contents of ATP, ADP, AMP with high performance liquid chromatography reflected the injury and energy metabolism of myocardial cell mitochondrial structure and function when being cultured together with Ang II. On that basis, cells were treated with Astragali Radix injection and valsartan for observing pharmacological effects on mitochondrial structure and function in restructured myocardial cells.

RESULTIn 72 h and 96 h, compare with the control group, the model group showed significantly increased total protein content and enlarged myocardial cell diameter. During the course of proliferation, the myocardial cell MAO activity and the injury percentage of mitochondrial outer membrane were significantly increased, with significant decrease in mitochondrial COX activity, mitochondrial Delta Psi m and the content of ATP, ADP and rise in the content of AMP. Astragali Radix injection and valsartan reduced myocardial cell total protein content and cell diameter caused by Ang II, decreased myocardial cell MAO activity, significantly increased mitochondrial COX activity and the content of ATP and ADP, and decreased the content of AMP.

CONCLUSIONDuring the process of myocardial hypertrophy, the injury of mitochondrial structure and function and the changes in myocardial cell energy metabolism injury occurred after the injury of mitochondria. Astragali Radix injection and valsartan can reverse myocardial cell mitochondrial structure and function during myocardial cell hypertrophy caused by Ang II. Reversion of myocardial cell hypertrophy and restructuring of myocardial cells helps improve energy metabolism of the myocardial cells.

Animals ; Astragalus Plant ; chemistry ; Cells, Cultured ; Drugs, Chinese Herbal ; administration & dosage ; therapeutic use ; Female ; Hypertrophy ; drug therapy ; Injections ; Male ; Membrane Potential, Mitochondrial ; drug effects ; Mitochondria, Heart ; drug effects ; Myocytes, Cardiac ; drug effects ; pathology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the protective effects of AduoLa Fuzhenglin(ADL) on the heart injury induced by microwave exposure in rats.

METHODSOne hundred forty male Wistar rats were divided randomly into 5 groups: control, microwave radiation, 0.75 g x kg(-1) d(-1) ADL, 1.50 g x kg(-1) d(-1) ADL and 3.00 g x kg(-1) d(-1) ADL pretreatment groups. Rats in three ADL pretreatment groups were administrated by ADL per day for 2w then exposed to 30 mW/cm2 microwaves for 15 min. The left ventricle blood of rats was obtained at 7 d and 14 d after exposure to microwaves, and the blood Ca2+, AST and CK were detected with Coulter automatic biochemical analyzer, then the histological changes and ultrastructure of heart were observed under light and electron microscopes.

RESULTSAt 7 d and 14 d after exposure to microwaves, the blood Ca2+, AST and CK concentrations significantly increased (P<0.05 or P<0.01) as compared with controls; Heart muscle fibers showed wavilness, endotheliocyte karyopyknosis, anachromasis; The mitochondria swelling and cavitation, intercalary dies blurred in radiation groups. The changes in 0.75 g x kg(-1) d(-1) ADL pretreatment group were similar to the radiation group, but in 1.50 g x kg(-1)d(-1) and 3.00 g x kg(-1) d(-1) ADL pretreatment groups, above indexes of rats significantly reduced as compared with microwaves group (P<0.05); also the blood Ca2+, AST, CK contents were significantly lower than those in microwave group (P<0.05); The heart showed a tendency to improve.

CONCLUSIONMicrowave radiation (30 mW/cm2) can cause the blood Ca2+, AST and CK turbulence, and heart injury in the histology and ultrastructure; ADL at the dosages of 1.50 g x kg(-1) d(-1) and 3.00 g x kg(-1) d(-1) has a protective effects on the heart injury induced by microwave in rats.

Animals ; Aspartate Aminotransferases ; blood ; Calcium ; blood ; Creatine Kinase ; blood ; Drugs, Chinese Herbal ; pharmacology ; Heart ; drug effects ; radiation effects ; Male ; Microwaves ; adverse effects ; Mitochondria, Heart ; radiation effects ; ultrastructure ; Myocardium ; pathology ; Rats ; Rats, Wistar

Animals ; Antioxidants ; pharmacology ; Drugs, Chinese Herbal ; pharmacology ; Fatigue ; prevention & control ; Male ; Mitochondria, Heart ; drug effects ; metabolism ; Oxidative Stress ; drug effects ; Panax ; chemistry ; Physical Exertion ; drug effects ; physiology ; Rats ; Rats, Sprague-Dawley

BACKGROUNDThioredoxin is one of the most important redox regulating proteins. Although thioredoxin has been shown to protect cells against different kinds of oxidative stress, the role of thioredoxin in myocardial ischemia and reperfusion injury has not been fully understood. This study was conducted to explore the protective role of human thioredoxin on myocardial ischemia and reperfusion injury and its potential mechanisms.

METHODSPurified human thioredoxin was injected into adult Wistar rats, which were subjected to 30 minutes of myocardial ischemia followed by 2 or 24 hours of reperfusion. We detected 1) the infarct size; 2) the level of malondisldehyde (MDA) in serum; 3) the expression of caspase-9, and cytochrome c in/out of mitochondria by Western blotting; 4) apoptosis by terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) assay and caspase-3 and its protein by reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting; 5) the expression of bcl-2 and bax in cardium by immunohistochemical (IHC) assay.

RESULTSHuman thioredoxin reduced myocardial ischemia/reperfusion injury as evidenced by significant decrease of myocardial infarct size (P < 0.01), notable reduction of myocyte apoptosis (P < 0.01), lower systemic oxidative stress level (P < 0.01) after reperfusion for 2 hours, and few inflammatory cell infiltration after reperfusion for 24 hours in rats. Furthermore, treatment with human thioredoxin significantly reduced the release of mitochondrial cytochrome C (P < 0.05), and inhibited the activity of caspase-9 (P < 0.05) and caspase-3 (P < 0.01 in mRNA and P < 0.05 at protein level). Meanwhile, human thioredoxin markedly increased bcl-2 expression (P < 0.05).

CONCLUSIONSThese results strongly suggest that human thioredoxin has cardioprotective effects on myocardial ischemia/reperfusion and its anti-apoptotic role may be mediated by modulating bcl-2 and the mitochondria-dependent apoptotic signaling pathway.

Animals ; Apoptosis ; drug effects ; Caspase 3 ; genetics ; Humans ; Mitochondria, Heart ; drug effects ; physiology ; Mitochondrial Membrane Transport Proteins ; drug effects ; Myocardial Reperfusion Injury ; prevention & control ; Oxidative Stress ; Rats ; Rats, Wistar ; Thioredoxins ; pharmacology

OBJECTIVE: To observe whether HSP70 could protect against H2O2-induced apoptosis in C2C12 myogenic cells by inhibiting Smac release from the mitochondria. METHODS: HSP70 gene and full length Smac gene was transiently transfected in C2C12 myogenic cells by lipofectamine and the protein levels of HSP70 and Smac were analysed by Western blotting. Hoechst 33 258 staining was used to examine cell morphological changes and to calculate percentage of apoptotic nuclei. DNA ladder pattern on agarose gel electrophoresis was used to observe the DNA fragmentation. Activities of caspase-3 and caspase-9 were assayed with Western blotting. The release of Smac from the mitochondria to the cytoplasm was observed by immunofluorescence. RESULTS: H2O2 ( 0.5 mmol/L ) activated caspase-3, caspase-9 8 h after the treatment and specific morphological changes of apoptosis 12 h after the treatment, and overexpression of Smac significantly promoted H2O2-induced activation of caspase-3, caspase-9 and apoptosis in C2C12 myogenic cells. HSP70 overexpression significantly inhibited H2O2-induced and Smac-promoted apoptosis, as shown by no specific DNA ladder pattern in agarose gel electrophoresis, decrease of percentage of apoptotic nuclei, and marked inactivation of caspase-3 and caspase-9. HSP70 could inhibit the release of Smac from the mitochondria to the cytoplasm 2 h after the treatment by H2O2. CONCLUSION HSP70 inhibits Smac release from the mitochondria and protects against H2O2-induced apoptosis in C2C12 myogenic cells.
Apoptosis ; drug effects ; Apoptosis Regulatory Proteins ; Cells, Cultured ; HSP70 Heat-Shock Proteins ; pharmacology ; Humans ; Hydrogen Peroxide ; Intracellular Signaling Peptides and Proteins ; metabolism ; Mitochondria, Heart ; drug effects ; metabolism ; Mitochondrial Proteins ; antagonists & inhibitors ; metabolism ; Myoblasts ; metabolism ; Myocytes, Cardiac ; drug effects ; metabolism

OBJECTIVETo investigate whether the cardioprotection of mitochondrial Slo channel (mitoSlo(1) channel) is associated with mitochondrial permeability transition in isolated rat hearts subjected to ischemia and reperfusion.

METHODSIsolated perfused rat hearts were subjected to 30 min regional ischemia (occlusion of left anterior descending artery) and 120 min reperfusion. The infarct size, lactate dehydrogenase (LDH) release during reperfusion and ventricular hemodynamic parameters were measured.

RESULTSPretreatment with mitoSlo(1) channel opener, NS1619 10 micromol/L for 10 min reduced the infarct size and LDH release, and improved the recovery of left ventricular developed pressure, left ventricular end-diastolic pressure, maximal rise/fall rate of left ventricular pressure and coronary flow during reperfusion. Administration of atractyloside (20 micromol/L), an opener of mitochondrial permeability transition pore, for 20 min (last 5 min of ischemia and first 15 min of reperfusion) attenuated the reduction of infarct size and LDH release and improvement of left ventricular performance induced by NS1619. In the isolated mitochondria, a significant inhibition of Ca(2+)-induced swelling was observed when mitochondria were incubated with NS1619.

CONCLUSIONMitoSlo(1) channel activation by NS1619 protects the myocardium against ischemia and reperfusion injury by inhibiting mitochondrial permeability transition pore opening.

Animals ; Atractyloside ; pharmacology ; Cardiotonic Agents ; pharmacology ; Heart ; In Vitro Techniques ; Ischemic Preconditioning, Myocardial ; Mitochondria, Heart ; drug effects ; Mitochondrial Membrane Transport Proteins ; Myocardial Reperfusion Injury ; metabolism ; prevention & control ; Permeability ; drug effects ; Potassium Channels ; metabolism ; Potassium Channels, Calcium-Activated ; metabolism ; Rats