The inhibitory effects of actinomycin D on chromatin (or DNA) template and the stimulating effects of synthetic template Poly [d(A-T)] on transcription were observed in the liver nucleic transcriptional system of the rat in vitor.By introducing proper concentrations of actinomycin D and Poly [d(A-T)] into each reactionary system,a method to assay free RNA polymerase activity in the nucleus was established.In addition,a comparison of the contents between chromatin-engaged and free polymerase in normal rat liver nuclei isolated with hypertonic sucrose (2.3 mol/L) was made.Eventually,the possible role free RNA Polymerases play in the eukaryotic transcriptional process was discussed.

The overall cellular gene expression is well realized by the coordinated regulation between nuclear DNA and mitochondria DNA. Coordinated regulation between two genomes plays a key role not only in mitochondria biogenesis and protein synthesis but also more importantly in the regulation of gene expression of mitochondria respiratory chain subunits in order to mediate the mitochondrial respiratory function. In the present review, we focus on the mechanism of coordinated regulation between two genomes.

Classroom teaching is the focus of teaching of school and main approach to medicine course,and the quality of classroom teaching is directly related to the development of students.Thus improving classroom teaching is very important to increase integral teaching of school.This paper discusses how to increase the thinking ability of students in classroom teaching.

We have reformed the traditional pathophysiological experimental teaching from improving experimental teaching method,optimizing experimental content,updating experimental teaching material,starting design experimental and founding general examine system.

Objective To understand the effect of transforming growth factor-?_(2)(TGF-?_(2)) on the expression and activity of matrix metalloproteinase-2(MMP_(2)) in cultured bovine trabecular cells and to investigate the role of TGF-?_(2) in the pathogenesis of primary open angle glaucoma(POAG). Methods TM cells were incubated in DMEM containing 1.0?g/L TGF-?_(2) or 1.0?g/L TGF-?_(2) with 100mg/L murine monocolonal anti-human PAI-1 IgG or DMEM without any experimental reagent for 24, 36, 48h, respectively. The expression of MMP_(2) or plasminogen activator inhibitor-1(PAI-1) were assayed by Western blot. Results TGF-?_(2 )could enhance the expression of pre-form MMP_(2) and PAI-1. PAI-1 neutralizing antibody could promote transformation of the pre-form MMP_(2) to it's active form. Conclusion TGF-?_(2) can cause the accumulation of ECM in trabecular meshwork by inhibiting the activation process of pre-form MMP_(2), and thus cause the increase of aqueous humor outflow resistance, which contributes to the pathogenesis of POAG.

Aim To understand the changing aspects of CAP-administration on expression of cytochrome C oxidase(COX) subunits I and IV and their mechanisms regulated by gene expression encoded by mtDNA and nDNA. Methods Wistar rats were randomly divided into control and CAP groups, Rats were administrated CAP(100 mg?kg -1, intraperitoneal injection) every 12 hours for 7 days before sacrificed by decapitation. Rat brain was removed and the cerebral cortex mitochondria was isolated by centrifugation programme. The protein content of COX subunitⅠand Ⅳ in mitochondria and NRF-1 in cerebral tissues was detected by Western blot analysis. And mRNA state levels of COXⅠ, COXⅣ, mtTFA and NRF-1 in tissues were determined by RT-PCR.Results Compared with C group, a decreased protein content of COX subunitⅠand an elevated ratio of subunit Ⅳ/Ⅰwas observed in CAP group, The protein content of COX subunit Ⅳ and NRF-1 as well as COXⅠ,Ⅳ,NRF-1 and mtTFA mRNA state level was not unchanged between the two groups. Conclusion The change of content of COX subunitⅠprotein in mitochondria from cerebral cortex showed there is no regulation of feedback to mitochondrial and nuclear transcription. The nuclear genomes expression does not correspond to mitochondrial expression in CAP-administrated rats.

Objective To explore the changes of expression levels of 12S rRNA and cytochrome oxidase subunit Ⅰ (COXⅠ) mRNA encoded by mtDNA in rat cerebral cortex after rat exposure to hypobaric hypoxia for different days. Methods Healthy male Wistar rats were exposed to hypobaric chamber simulating 5 000 m above sea level (23 5 h/day) for 2, 5, 15 and 30 d. Rats in the control group were not exposed to hypoxia. Rats were sacrificed by decapitation. Total RNA in cerebral cortex was extracted using a standard program. Transcriptional levels of 12S rRNA and COXⅠ mRNA were determined by reverse transcription polymerase chain reaction (RT PCR). Results Compared with that in the control, the expression of 12S rRNA increased by 57% after hypoxic exposure for 2 d ( P 0 05). Compared with that in the control group, the expression of COXⅠ mRNA increased significantly by 55% and 106% after hypoxic exposure for 2 and 5 d ( P 0 05). Conclusion Hypoxic exposure may have effect on both protein gene and ribosome gene expression encoded by mtDNA, and the expression changes in a hypoxic exposure time dependent manner. This suggests that hypoxia can have effect on mitochondrial oxidative phosphorylation gene expression at both mitochondrial transcriptional and translational levels.

Objective To observe the changes of rat brain mitochondrial uncoupling protein (UCP) content and activity, and explore the effect of UCP on mitochondrial energy metabolism during hypoxia exposure. Methods Adult SD rats were set randomly into control and hypoxia group (n=8 in each group). The rats of hypoxia group were put into a hypobaric chamber simulating 5000-meter high altitude for 3 days (23 h/d). The brain mitochondria was isolated by centrifugation. Mitochondrial oxidative respiratory function was measured by Clark oxygen electrode. Mitochondrial membrane potential was detected by Rhodamine123 method. The content of adenine nucleotide pool (ATP, ADP, AMP) in mitochondria was measured by high performance liquid chromatography. UCP content and activity were detected by [~ 3 H]-GTP binding method. Results High altitude hypoxia resulted in significant increase of UCP activity and a 2.9-fold rise of UCP content of rats (P

Objective To investigate effect of guanosine diphosphate (GDP) on the mitochondrial respiratory oxygen consumption and the mitochondrial membrane potential (MMP) of rat brain and explore the relationship of the change of uncoupling proteins (UCPS) activity with the oxygen consumption and MMP. Methods The mitochondria of rat brain were isolated by centrifugation. Mitochondria oxidative respiratory consumption was measured by Clark electrode after the treatment of GDP at different concentrations so as to calculate mitochondrial state 3 respiration (ST3), mitochondrial state 4 respiration (ST4), respiratory control rate (RCR), and the rate of oxidative phosphorylation (OPR). MMP was detected by Rhodamine 123 method at the different concentrations of GDP. Results With the increase of GDP concentration form 0 to 1.0 mmol/L, the values of ST3, ST4 and OPR were reduced while RCR was elevated. But when the concentration increased to 1.4 mmol/L, the former 3 indexes begun to increase while the later declined. When the GDP concentration reached to 1 mmol/L, the inhibitory rate was only 35.1%, 51.3%, 14.2% to ST3, ST4 and OPR respectively, while RCR was increased to 133.2%. No matter the concentration was over 1 mmol/L or under 1 mmol/L, the ability of inhibition was attenuated. MMP reached to the highest point when GDP exerted the highest inhibitory rate on mitochondrial respiratory oxygen consumption. Conclusion GDP, an inhibitor of UCPS, can regulate the respiratory oxygen consumption and MMP of the isolated rat brain mitochondrial directly in a dose-effect fashion. The change of UCPS activity can affect the respiratory oxygen consumption and MMP.

Objective To understand the changing aspects of CAP-administration on mitochondrial oxidative phosphorylation function and cytochrome c oxidase (COX) activity during hypoxia exposure and their mechanisms. Methods Except the control group (C group), adult male Wistar rats were exposed to a hypobaric chamber simulated 5 000-meter high altitude for 23 h every day for 0, 1, 5, 15, 30 d (H_ 0, 1, 5, 15, 30 ) respectively and administrated CAP (100 mg/kg, intraperitoneal injection) every 12 h for 7 d before sacrificed by decapitation. Mitochondrial respiratory function and COX activity were measured by Clark oxygen electrode and polarography, respectively. Results As compared with C group, mitochondrial state 3 respiration (ST_3) and respiratory control rate (RCR) and oxidative phosphorylation rate (ORP) and COX activity in H_0+CAP group all decreased significantly, but by prolonging hypoxia exposure increased and restored to the control level. Conclusion Mitochondrial respiratory function, oxidative phosphorylation efficiency and COX activity in rat brain could improve by administrating CAP during hypoxia exposure and almost reach to the control level by prolonging hypoxia exposure.