To investigate the mechanisms of hepatic injury after biliary obstruction. After a rat model of complete biliary obstruction(CBO) was induced, hepatocyte mitochondria was isolated and the calcium content of mitochondria, the contents of liver malondialdyhyde (MDA) and superoxide dismutase (SOD), the levels of serum T-Bil, ALT, ALP and GGT were measured in each group. Results: After CBO, mitochondrial calcium content, liver MDA and serum T-Bil, ALT, ALP, GGT became increased progressively, compared with control group (Ｐ＜0.05); the liver SOD was decreased markedly (Ｐ＜0.05). Mitochondrial calcium content was highly positively correlated with liver MDA content, serum ALT and ALP, r values were 0.967, 0.924 and 0.919 respectively (Ｐ＜0.01). The liver MDA content was highly positively correlated with serum ALT and ALP, r values were 0.949 and 0.843 respectively (Ｐ＜0.01). Conclusions: Mitochondrial calcium overload and liver lipid peroxidation may be the important mechanisms of hepatic injury induced by biliary obstruction.
【Abstract】 Objective To analyze the correlations between the mt5351G and mt6680C genotypes in mitochondrial DNA ( mtDNA) haplogroup M and susceptibility to high altitude pulmonary edema ( HAPE)among the Hans. Methods Specimens from206 Hans cases of HAPE and 144 matched Hans controls were collected. Then PCR-RFLP method was used to determine haplogroup M and N of mtDNA, and PCR-LDR was used to genotype mt5351G and mt6680C in the haplogroup M in these samples. Results The frequencies of haplogroup Mand N were 49. 0% and 51.0% in the HAPE patients, and 47. 2% and 52. 8% in the controls, respectively, with no significant difference between the HAPE patients and the controls. In the haplogroup M, the genotype of mt6680C and mt5351G frequencies in the HAPE patients were both significantly higher than the controls ( both 12. 0% vs. 1. 5% , P = 0. 016) . Conclusion The existence of mt5351G and mt6680C genotypes in the haplogroup Mis a risk factor for HAPE among the Hans.
The main function of mitochondrial fusion protein 1 （Mfn1） and mitochondrial fusion protein 2 （Mfn2） was originally thought to be just regulating the fusion of mitochondrial outer membrane. But in recent years，many studies on these two proteins show that they are involved in many important cellular physiological processes including proliferation，apoptosis，necrosis and regulation of respiratory function and oxidative metabolism. There are many aspects of the influenceof Mfn1 and Mfn2 on cardiomyocyte，which have not been thoroughly studied yet，sometimes with even contradictoryconclusions. But these two proteins definitely have significant impact on the growth，development and physiological functionof cardiomyocyte. To investigate the function and mechanism of Mfn1 and Mfn2 in various physiological processes of cardiomyocyte is of great significance for in vitro studies of physiological functions of cardiomyocyte and technological development of myocardial tissue engineering and transplantation in vivo. This article mainly focuses on recent research progress of the influence of Mfn1 and Mfn2 on various physiological functions of cardiomyocyte.
Objective To investigate the role of mitochondrial adenosine triphosphatesensitive potassium channel(mitoKATP) in immature myocardial ischemic preconditioning, and to provide evidence for immature myocardial protection. Methods Langendorff isolated heart infused model was used in the experiment. Twentyfour rabbits (aged from 14 to 21 days) were randomly divided into 4 groups：ischemiareperfusion group（I/R group）, myocardial ischemic preconditioning group(E1 group), 5hydroxydecanoate(5-HD) group (E2 group) and Diazoxide (Diaz) group(E3 group). Hemodynamics recovery rate, myocardial water content(MWC), the leakage rates of serum creatine kinase and lactate dehydrogenase, adenosine triphosphate content, superoxide dismutase activity, malondialdehyde content, myocardial cell Ca2+ content and myocardial mitochondrial Ca2+ content, myocardial mitochondrial Ca2+-ATPase activity, the adenosine triphosphate(ATP) synthesizing ability of myocardial mitochondria were tested, and myocardial ultrastructure was observed via electron microscopy. Results The hemodynamics recovery rate, myocardial water content(P＜0.05), adenosine triphosphate content, superoxide dismutase activity, myocardial mitochondrial Ca2+-adenosine triphosphyatase(ATPase) activity and the ATP synthesizing ability of myocardial mitochondria of the rabbits in E1 and E3 group were significantly better than that in I/R group and E2 group(P＜0.05). Malondialdehyde content, the leakage rates of serum creatine kinase and lactate dehydrogenase, myocardial cell Ca2+ content and myocardial mitochondrial Ca2+ content of the rabbits in E1 group and E3 group were significantly lower than that in I/R group and E2 group (P＜0.05). The myocardial ultrastructure injury in E1 and E3 group were significantly reduced compared with that in I/R and E2 group. Conclusion Myocardial ischemic preconditioning has significant protective effects on immature myocardium. Its mechanism may be related to the activation of mitoKATP.
Objective To investigate the protective effects of ischemic postconditioning (IPo) on ischemiareperfusion (I/R) myocardium and the relationship with mitochondrial adenosine triphosphate (ATP) sensitive K+ channels (mitoKATP) and provide evidences to the development of druginduced postconditioning. Methods Langendorff models were established in 40 Wistar rats which were divided into 5 groups by random number table with 8 rats in each group. Normal control group(NC group): the rat hearts were continuously reperfused by KrebsHenseleit bicarbonate buffer (K-HB) for 100 min without any other treatment; I/R group: the rat hearts underwent a 40-min global ischemia followed by a 60-min reperfusion; IPo group: after a 40-min global ischemia, the process of 10-second reperfusion followed by a 10-second ischemia was repeated 6 times, then there was a continuous 58min reperfusion; 5-hydroxydecanoic acid(5-HD) group: after a 40min global ischemia, hearts with 5HD(100 μmol/L) K-HB were reperfused for 15min and then perfused without 5HD for 45min；IPo+5-HD group: after a 40-min global ischemia, the process that the isolated hearts with 5-HD(100 μmol/L) KHB were reperfused for 10second followed by a 10second ischemia was repeated 6 times, then the hearts with 5-HD(100 μmol/L) KHB were continuously [CM(159mm]perfused for 13-min followed by reperfusion without 5-HD(100 μmol/L) K-HB for 45-min. The cardiac function,coronary flow(CF), cardiac troponin I(cTnI) content in coronary effluent, the area of acute myocardial infarction (AMI) and myocardial ultrastructure were observed. Results Left ventricular developed pressure(74.3±3.3 mm Hg vs. 57.1±3.3 mm Hg,t=1300, P=0.000),+dp/dtmax(1 706.6±135.6 mm Hg/s vs. 1 313.3±96.2 mm Hg/s,t=6.28,P=0.000),－dp/dtmax(1 132.8±112.1 mm Hg/s vs. 575.7±67.7 mm Hg/s,t=13.48, P=0.000) and CF(6.49±0.30 ml/min vs. 3.70±0.24 ml/min,t=28.6,P=0.000) in IPo group were higher than those in I/R group. Left ventricular enddiastolic pressure(10.9±1.7mm Hg vs. 26.2±1.5 mm Hg,t=－19.21, P=0000)and cTnI content in coronary effluent (0.62±0.01 ng/ml vs. 0.71±0.01 ng/ml, t=-12.00,P=0.000) were lower than those in I/R group; the area of AMI decreased 20.8％ compared with that in I/R group (Plt;0.05). The myocardial protective effect in IPo+5HD group was similar with that in IPo group, but lower than that in IPo group. The electron microscope showed that IPo and IPo+5HD could reduce myocardial fiber damage and mitochondrial damage caused by I/R. Conclusion IPo can protect I/R myocardium, which is achieved mainly by activating mitoK-ATP channels.
Objective To investigate the preventive and therapeutic effects and the mechanisms of pyrrol idine dithiocarbamate (PDTC) on the atrophy of denervated skeletal muscle. Methods Thirty adult Wistar rats of either gender, weighing (200 ± 10) g were randomly divided into 3 groups: group A (n=6, control group), group B (n=12, denervation group), and group C (n=12, PDTC treatment group). The sciatic nerves of the rats were only exposed without cutting off in group A, and the rats were made denervated gastrocnemius models in groups B and C. PDTC of 100 mg/(kg•d) was injected peritoneally in group C and an intraperitoneal injection of the same amount normal sal ine was given in group B. After 14 and 28 days, the gastrocnemius was harvested to measure the ratio of muscle wet weight; the levels of nuclear factor of κB (NF-κB)p65 protein and the opening of the mitochondrial permeabil ity transition pore (MPTP) in the gastrocnemius were detectedrespectively by Western blot and laser confocal scanning microscope; and the apoptotic cells in atrophic muscle were measured with TUNEL. Results The ratio of muscle wet weight in group A was 1.039 ± 0.115, and it significantly decreased in groups B and C (P lt; 0.05); after 14 and 28 days of operation, the ratio of muscle wet weight in group C significantly increased when compared with those in group B (P lt; 0.05). The expression of NF-κB p65 protein in group A was 0.224 ± 0.041; the expressions of NF-κB p65 in groups B and C significantly increased when compared with that in group A (P lt; 0.05); however, the expression of NF-κB p65 in group C was significantly lower than that in group B (P lt; 0.05). The MPTP fluorescence intensity in group A was 31.582 ± 1.754; the MPTP fluorescence intensity was significantly lower in groups B and C than in group A (P lt; 0.05), and the MPTP fluorescence intensity in group C was significantly higher than that in group B (P lt; 0.05). The rate of apoptosis in group A was 4.542% ± 0.722%; after 14 and 28 days of operation, the rates of apoptosis significantly increased when compared groups B and C with group A, and signiticantly decreased when compared group C with group B (P lt; 0.05). Conclusion PDTC can retard denervated skeletal muscle atrophy, and the effect may have a relationship with its inhibition on NF-κB, the opening of the MPTP, and the ratio of apoptosis.
Objective To observe the retinal manifestations and classification of mitochondrial encephalomyopathy，and explore the relationship between retinopathy and systemic manifestations.Method The clinical data of 88 inpatients with mitochondrial encephalomyopathy were retrospectively analyzed，in whom 12 patients（24 eyes）with retinal manifestations who diagnosed by ophthalmology consultation and complete medical records were collected. There were nine males and three females aged from 14 to 33 years with the mean age of（20.1±7.0）years. The disease duration ranged from 2.5 to 20 years，with the mean of（9.5±6.8）years. All the patients had the eye symptoms of the different degree，such as limbs weakness，hearing decline and central nervous system symptoms. Ophthalmologic examination including best corrected visual acuity，slit lampa microscope，indirect ophthalmoscopy，noncontact Tonometer，ptosis，ocular movement，pupillary reflex and color fundus photography. Among the patients，three，one，two and five patients had undergone fundus fluorescein angiography（FFA），optical coherence tomography（OCT），lectroretinogram（ERG）and visual field examination respectively. Diabetic retinopathy were divided into “salt and pepper”， retinitis pigmentosa（RP），retinal pigment epithelium（RPE），choroidal capillary atrophy and simplex optic atrophy according to the inspection results.Results All the patients′ both eyes were involved，the disease degree of bilateral eyes was accordant. The ptosis and（or）eye movement limitation were found in nine patients（75.0%），and decreased visual acuity was in six patients（50.0%）.“Salt and pepper” was found in six patients（12 eyes），presenting retinal granular pigmentation and depigmentation；the visual acuity was 0.4-1.2；no central nervous system symptoms were found in patients，such as hearing decline，twitch，ataxia and hypophrenia. RP was found in one patient（two eyes），presenting retinal cells sample pigmentation，retinal vessel shrink，optic atrophy；the vision were light perception in both eyes；hypophrenia，hearing decline，bilateral lower limbs pain and onset twitch were also found in them. RPE and choroidal capillary atrophy were found in three patients（six eyes），the choroidal great vessels and flake pigment accumulation surrounding the retina were observed；the visual acuity was hand movement0.7；limbs weakness was found in two patients；hearing decline was found in three patients；barylalia and hypophrenia were found in two patients；somnolence was found in one patient. Simplex optic atrophy was found in two patients（four eyes）；the vision was 0.1-0.7；central nervous system symptoms were found in patients，such as limbs weakness，twitch，hypophrenia and headache.Conclusion Retinopathy types is concerned with visual prognosis and central nervous system symptoms.
Purpose To investigate the relationship between mitochondrial DNA 11778 mutation and clinical characteristics of patients with Laber is hereditary optic neuropathy(LHON). Methods PCR RFLPs (MaeⅢ) and mutation specific primer PCR(MSP-PCR) were used simultaneously to detect mitochondrial DNA 11778 mutation. Results Among 10 subjects who habored 11778 mutation,one was a carrier and nine were patients with LHON.Of the nine patients,six were males and three were females.The age of onset ranged from 12 to 25 years old and the onset interval of the two eyed varied between 0 to 6 months. The visual acuity was CF/10cm-0.1 except one who lost her vision after delivery but recovered gradually.The results of visual field,VEP and color vision were abnormal but ERG and systemic status were all normal. Conclusion Molecular biological detection of the ten subjects showed that they all habored mtDNA 11778 mutation.The existence of carrier and visual recovery imlied that mtDNA mutation was a primary cause of LHON,but other factors such as endocrine disorder might influence the pathogenesis of LHON. (Chin J Ocul Fundus Dis,1998,14:156-158)
Objective To explore the relationship between microsatellite instability （MSI） and gastric cancer. Methods The related literatures at home and abroad were consulted and reviewed. Results The MSI is the replication errors caused by mismatch repair system defects. Gastric cancer which exhibiting MSI has characteris clinicopathological feature and prognosis. Detection the MSI of precancerous lesions and gastric cancer tissues can evaluate the risk and prognosis of gastric cancer. MSI include nuclear microsatellite stability （nMSI） and mitochondrial microsatellite instability （mtMSI）. Conclusions MSI plays an important role in the occurrence and development of gastric cancer. MSI may become a important indicator to forecast precancerosis risks and clinical prognosis of gastric cancer.
Objective To explore the feasibility of identifying clonal origin of hepatocellular carcinoma (HCC) by analyzing the mitochondrial DNA D-Loop region variations. Methods Forty-two patients with a total of 112 HCC nodules consequentially hospitalized for radical resection of HCC in the department of hepatobiliary surgery of the First Affiliated Hospital of Guangxi Medical University from April 2004 to August 2007 were included for study group (multinodular HCCs). Control group included 20 cases of HCC (40 samples) hospitalized in the same period that consisted of two sub-groups: control groupⅠconsisted of 16 cases of single nodular HCC that each had two pieces of inconsecutive tumor tissues and control groupⅡconsisted of 4 cases of HCC with portal vein tumor embolus whose tumor tissues and portal vein tumor embolus were collected simultaneously. Normal control included 5 patients who were donors for liver transplantation or underwent liver trauma without any liver disease. Polymerase chain reaction (PCR) and direct sequencing were applied to study the mtDNA D-Loop region. The sequences of multinodular lesions were compared among different groups. Results For all the 42 cases of the study group, basic group variations appeared in 131 sites (131/1 122, 11.7%, the number 1 122 was the length of mtDNA D-Loop) with point mutation in 15 sites, insert in 9 sites, and deletion in 16 sites. And of all the variations in the study group, 98 were polymorphism. In study group, 20 cases were categorized as multicentric occurrence (MO) based on their variant mtDNA D-Loop sequences in each nodule from the same patient. And 22 cases were characterized as intrahepatic metastasis (IM) based on the identical mtDNA D-Loop sequences found in each nodule from the same patient. In all 20 cases in the control group, the inconsecutive tumor tissues or the portal vein tumor embolus and original tumors shared identical mtDNA D-Loop sequences. For the normal control group, basic group variations appeared in 14 sites, and they were all polymorphism including a new polymorphism (NT 479 Agt;G). Conclusions There is a high rate of changes in mtDNA D-Loop region. And our study speculates a novel discrimination of MO and IM origins among multinodular HCCs using PCR and direct sequencing of the mtDNA D-Loop sequences.