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@#AIM:To investigate the protective effect of adiponectin on hypoxia-damaged rhesus monkey choroid /retinal vascular endothelial cells(RF/6A)and related mechanisms. <p>METHODS:<i>In vitro</i> cultured RF/6A cells were randomly divided into the control group, hypoxic injury(induced by CoCl2 stimulation)group and hypoxic injury + adiponectin(5μmol/L, 50μmol/L and 100μmol/L)group. Cell viability was assessed using the MTT assay and optimal concentration of adiponectin was selected. Western blot was used to detect the expression of Bax and Bcl-2 in RF/6A cells. Reactive oxygen species(ROS)detection kit was used to detect the content of ROS in RF/6A cells. <p>RESULTS: Compared with the control group, the cell viability of RF/6A cells in the hypoxic injury group and each adiponectin pretreatment group decreased(all <i>P</i><0.01). Compared with the hypoxic injury group, the cell viability of RF/6A cells in each adiponectin pretreatment group was significantly increased(all <i>P</i><0.05), and adiponectin of 50μmol/L was the appropriate protective concentration. Compared with the control group, the viability of RF/6A cells decreased, the protein expression level of Bax increased, the protein expression level of Bcl-2 decreased, and the content of ROS increased in the hypoxic injury group(all <i>P</i><0.01). Compared with the hypoxic injury group, the viability RF/6A cells increased, the expression level of Bax decreased, the expression level of Bcl-2 increased, and the content of ROS decreased in the adiponectin pretreatment group(all <i>P</i><0.01).<p>CONCLUSION: Our findings suggest that adiponectin can significantly alleviate retinal vascular endothelial cell damage and apoptosis caused by hypoxia, and the mechanism may be related to the inhibition of oxidative stress by adiponectin.
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@#[Abstract] Objective: To investigate the expression level of lncRNA (long non-coding RNA) SNHG1 in endometrial cancer tissues, and to analyze its mechanism of action as well as its clinical significance. Methods: NCBI-GEO and TCGA database were used to analyze the expression level of SNHG1 in endometrial cancer. A total of 53 cases of endometrial cancer tissue samples and 41 cases of normal endometrial tissue samples were collected from January 2016 to March 2019 at Zhongxin Ecocity Hospital of Tianjin Medical University; in addition, endometrial cancer cell lines Ishikawa and HEC-1A as well as normal endometrial ESC cells were also collected for this study. qPCR was used to detect the expression level of SNHG1 in tissues and cells, and its correlation with the clinical characteristics of patients were statistically analyzed. The effect of SNHG1 on cell proliferation and apoptosis of HEC-1A cells was measured by MTT assay and Annexin V/PI double staining Flow cytometry, respectively. The migration and invasion of HEC-1A cells were measured by Transwell assay. StarBase was used to predict the regulatory relationship between SNHG1 and RELA, which was then verified by qPCR and Western blotting. Dual fluorescent reporter gene system and qPCR were adopted to identify the influence of SNHG1 on NF-κB pathway. Results: The expression of SNHG1 was significantly up-regulated in endometrial cancer tissues compared with normal endometrial tissues (P<0.01), and its expression was related to tumor size, TNM staging, histological grade and lymph node metastasis (all P<0.05). The expression level of SNHG1 in Ishikawa and HEC-1A cells was significantly higher than that in ESC cells (all P<0.01). Overexpression of SNHG1 notably promoted the proliferation, migration and invasion and inhibited cell apoptosis of HEC-1A cells. By promoting the expression of RELA, SNHG1 activated the NF-κB pathway and promoted the expressions of downstream gene IL-6 and CCL19 (all P<0.01). Conclusion: Up-regulated SNHG1 in endometrial cancer functions as an oncogene by activating the NF-κB pathway through promoting the RELA expression.
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Objective: To explore the inductive effect of galangin on HPV-positive human cervical cancer cells and the possible mechanism. Methods: Two HPV-positive human cervical cancer cell lines (SiHa cell and HeLa cell) and one HPV-negative human cervical cancer cell line (C-33-A cell) were given different concentration of galangin (20, 40, and 80 μmol/L) for 24, 48, and 72 h. Three human cervical cancer cell lines and relative cell viabilities were determined by the MTT method. Apoptosis and cell cycle were analyzed by flow cytometry. Western blotting analysis was used to determine the protein expression levels of Bcl-2 family proteins. Results: Cell proliferation of two HPV-positive human cervical cancer cells was significantly inhibited by galangin in a dose- and time-dependent manner, and galangin had no effect on cell proliferation of HPV-negative human cervical cancer cells. Cell cycle detection results showed that galangin could reversibly arrest the two HPV-positive cell lines, either in G1 or in G2/M phases. Flow cytometry results showed that beyond certain galangin concentration or/and over 24 h exposure, the cells underwent apoptosis. The data of Western blotting showed that 40 μmol/L galangin up-regulated the expression levels of Bad, Bid, and Bax, but down-regulated Bcl-2 and Bcl-w. Conclusion: Galangin can inhibit the proliferation of HPV-positive cervical cancer cells and promote apoptosis, which may be associated with the regulation of Bcl-2 family proteins expression.
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AIM: To investigate the angiogenesis effect and protective mechanism of cordycepin on rhesus macaque choroid- retinal endothelial ( RF/ 6A) cell line cultured in high glucose condition. METHODS: Cultured RF/ 6A cells were divided into normal control group, high glucose group and high glucose (HG) + different concentration cordycepin groups (HG+ 10μ g/ mL group, HG+ 50μ g/ mL group, HG+ 100μ g/mL group). The cell proliferation was assessed using cholecystokinin octapeptide dye after treated for 48h. The cell migration was investigated by a Transwell assay. The tube formation was measured on Matrigel. Furthermore, the impact of cordycepin on high glucose - induced activation of VEGF and VEGF receptor 2 (VEGFR-2) was tested by Western blot analysis. RESULTS: Compared with normal control group, cell viability markedly increased in high glucose group ( P CONCLUSION: Cordycepin can suppress the proliferation, migration and tubu formation of RF/ 6A in high glucose condition, might via inhibiting expression of VEGF and VEGFR-2.
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Objective To discuss the impact of the neurotoxity of bupivacaine and bupivacaine-induced cellular neurotoxicity caused by pretreatment of ganglion (GM-1 )monoglyceride on the ex-pression of caspase-3.Methods The mouse neuroblastoma cells-N2a cells was used as a research object to carry out the following experiments:(1)To observe the damage effects of different concen-trations of bupivacaine on N2a cells and find out the most suitable damage concentration to establish cell damage model.The N2a cells were interacted with bupivacaine with different concentrations [0μmol/L (group C),600 μmol/L (group B1),900 μmol/L (group B2),1 200 μmol/L (group B3), 1 500 μmol/L (group B4),2 000 μmol/L (group B5)]for 6,12,24,36 h and then evaluated by CCK-8 cell survival.Each experiment was repeated three times.The protective function of GM-1 to bupiva-caine-induced N2a cells damage.The N2a cells were treated with different concentrations (0.1μmol/L (group BG1),1.0 μmol/L (group BG2),10 μmol/L (group BG3))of GM-1 pretreatment 24 h,CCK-8 was evaluated in cell viability,Western Blot method was used to detect damaged cells caspase-3 expression levels.Each experiment was repeated three times.Results (1)Bupivacaine could significantly damage N2a cells,the greater the bupivacaine concentration,the longer the action time,the stronger neurotoxicity.(2)GM-1 bupivacaine nerve injury had a significant protective effect in a dose-related manner.The maximum of protective dose of this experiment was 10 μmol/L.Conclusion Bupivacaine can significantly damage N2a cells,correlating with both dose and time double positively,while GM-1 pretreatment significantly reduced the expression of caspase-3 induced by bupivacaine.
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AIM:To observe the neuritogenic actions of botulinum neurotoxin serotype A heavy chain ( BoNT/A HC) on cultured Neuro-2a cells and to investigate the related signaling mechanisms for the effect of BoNT /A HC. METHODS:Neuro-2a cells were treated with different doses of BoNT/A HC (0.01, 0.1, 1 and 10 nmol/L), and then the cells were harvested at 24 h, 48 h and 72 h of BoNT/A HC exposure for detecting the neurite length and the percen-tage of the cells with neuronal processes by immunofluorescence staining .The most efficient dose of BoNT/A HC was cho-sen for exposure to Neuro-2a cells as the above.Whole cell protein was harvested at different time points for detecting the protein levels of phosphorylated ERK 1/2 ( p-ERK1/2 ) and phosphorylated Akt ( p-Akt ) by Western blot .RESULTS:Low doses of BoNT/A HC stimulated the neurite outgrowth , and increased the percentage of the cells with neurites com-pared with the negative controls (P<0.05), especially in the group with 1 nmol/L of BoNT/A HC treatment.Meanwhile, the phosphorylation of ERK 1/2 and Akt was increased after treated with BoNT/A HC.There was an increasing tendency for the phosphorylation of ERK1/2 after the exposure of the cells to BoNT/A HC.The obvious increase in p-ERK1/2 was seen from 60 min to 5 h with 1 nmol/L of BoNT/A HC treatment ( P<0.05 ) , and the increased protein level of p-Akt was mainly observed at 15 min and 60 min ( P<0.05 ) .CONCLUSION: BoNT/A HC stimulates the neuritogenesis .The neuritogenic mechanism of BoNT/A HC on Neuro-2a cells might be realized by activation of the phosphorylation of ERK 1/2 and Akt.
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Calotropis procera (Ait.) R. Br (Asclepiadaceae) is a species widely used in traditional medicine for the treatment of various diseases such as sickle cell disease, asthma and cancer. In Burkina Faso, it enter in the composition of FACA® in combination with Zanthoxylum zanthoxyloides Lam (Rutaceae), drug used in sickle cell disease treatment. The objective of this study was to evaluate the in vitro cytotoxicity of aqueous extract of root barks of the plant on cell lines to increase the safe use of FACA®. MTT and Neutral Red assays performed on Caco-2 and Neuro-2a cell lines revealed that aqueous extract from root barks of Calotropis procera are cytotoxic on these cell lines. DNA fragmentation assay on Caco-2 cell showed DNA smearing reflecting a degradation of nuclear material that indicates a possible genotoxicity. Altogether, it comes out that the most sensitive cell line is the human colorectal carcinoma Caco-2 cells. Comparatively the active compounds of Calotropis procera do not affect the mice nervous system cells in the same dramatic extent. Our results strongly suggest that patients under treatment of FACA® must respect doses prescribed in order to avoid adverse side effects on the gastrointestinal tract.
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Objective To amplify the recombinant adenovirus vector carrying rat angiotensin Ⅱ type 2 receptor (AT2R) gene using human embryonic kidney (HEK) 293A cell lines and to construct a pancreatic islet βcell model overexpressing AT2R by transfecting the adenovirus vector into rat insulinoma (INS-1) cell lines.Methods Recombinant adenovirus vector Ad-G-AT2R-EGFP and control vector Ad-CMV-EGFP were amplified with HEK 293A cells and the titer of the adenovirus was detected .After both adenovirus vectors were transfected into INS-1 cells,AT2R and angiotensin Ⅱtype 1 receptor(AT1R) gene expressions were tested using real-time PCR, Western blotting, immunofluorescence staining and confocal laser-scanning microscopy .Results The titer of amplified Ad-G-AT2R-EGFP and Ad-CMV-EGFP was re-spectively 9 ×109 pfu/ml and 8 ×109 pfu/ml.Transfection of Ad-G-AT2R-EGFP into INS-1 cells induced an increase in AT2R mRNA expression in a dose-dependent manner , and significantly increased AT2R mRNA and protein expression compared with Ad-CMV-EGFP-or mock-transfection.Conclusion The recombinant adenoviral vector carrying AT2R gene is successfully amplified and an INS-1 cell model overexpressing AT2R is constructed by transient transfection , which can contribute to further study of the role of AT2R in pancreatic islet βcells.
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Objective:To investigate the effects of deguelin on the viability and apoptosis of Neuro-2A ( N2A) cells. Methods:The cell viability of N2A cells with the density of 5 × 104 ·ml-1 on the time points of 6, 12, 24, 48 and 72 hours after 1 × 10 -8 mol ·L-1 deguelin treatment using CCK-8 kits was determined, and that on the time point of 48 hours after 0, 1 × 10 -11 , 1 × 10 -10 , 1 × 10 -9 , 1 × 10 -8 , 1 × 10 -7 , 1 × 10 -6 or 5 × 10 -4 mol·L-1 deguelin treatment was also detected. The activity of caspase 3 was deter-mined in N2A cells treated by 2 × 10 -8 mol·L-1 deguelin for 24 hours. Results:N2A cells with the density of 5 × 104 ·ml-1 reached the peak level in the growth curve 48 hours after the incubation in DMEM medium with 10% fetal bovine serum. The cell viability of N2A cells was decreased after the treatment of 1 × 10 -8 mol·L-1 deguelin for 24-72 hours in a time-dependant manner or after the treatment of 1 × 10 -8 ~1 × 10 -6 mol·L-1 deguelin for 48 hours in a dose-dependant manner (P<0. 05) with IC50 of 1. 6 × 10 -8 mol ·L-1 . The activity of caspase 3 was increased after the treatment of 2 × 10 -8 mol·L-1 deguelin for 24 hours, which was 5. 6-fold of that in the control group. Conclusion: Cell viability of N2A cells is inhibited by deguelin in a time- and dose-dependent manner, which may be related to the activity increase of caspase 3.
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Objective To construct the lamino acid transporter 1 eukaryotic expression vector of C 57 mouse and to express the gene inNeuro-2atumor cells,and explore the effect of LAT1on proliferation and apoptosis of Neuro-2a cell. Methods The full-length LAT1 cDNA was synthesized by RT-PCR and cloned into pcDNA3.1vector to construct recombinant plasmid.The constructed pcDNA3.1-LAT1vector was verified by Enzyme digestion and sequencing and then transfected intomurine Neuro-2acellsby liposome.The transfected cells were selected with G418 and stably expressed strain was constructed .The expression of LAT1 was detected by RT-PCR and western blot .Proliferation was analyzed by MTT , cell cycle and apoptosis were detected by flow cytometric analysis .Results The full-length LAT1 cDNA was amplified successfully and pcDNA3.1-LAT1eukaryoticvector was constructed successfully .Enzyme digestion and sequencing confirmed the sequence was correct .Neuro-2acells were transfected and Stably expressed strain was constructed successfully.MTT showed that the group of transfected restructuring plasmid could significantly affect Neuro -2a cell proliferation more than the control groups ( P <0.05 ) .From the flowcytometric analysis , LAT1 could promote cell proliferation and inhibit Neuro-2a cell apoptosis.Conclusion LAT1 can express successfully inNeuro-2acells which were transfected with recombinantpcDNA3.1-LAT1plasmid.LAT1 in Neuro-2a cells can promote cell proliferation and inhibit the cell apoptosis which provides a basis for the study of LAT 1.That lays the foundation for studying biological effects of LAT 1.
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Background and purpose:DNMT3B has nearly 40 known splice variants expressed in a tissue-and disease-speciifc manner, but the roles of these splice variants in the cell are still unclear. The aim of this study was to investigate the effects of overexpression of DNA methyltransferase 3B4 (DNMT3B4) gene on proliferation of human embryo kidney 293A cells. Methods:293A cells were transfected with plasmid pCMV-DNMT3B4 or pCMV-2B and then treated with G418 to get the stable cell line. The stable cell lines were determined for proliferation level by MTT method, and for cell cycle distribution by lfow cytometry. The expression of p21 was detected by real-time PCR and Western blot. The methylation status of p21 gene promoter was detected by methylation-speciifc PCR (MS-PCR). Results:The absorbance value in DNMT3B4-1 and DNMT3B4-2 clone were (58.92±3.47)%and (68.82±5.64)%as compared to 293A-vector cells using MTT method. DNMT3B4 overexpression signiifcantly decreased cell proliferation (P<0.05). S phase fraction of 293A-vector cells was (40.44±0.91)%. While in DNMT3B4-1 and DNMT3B4-2 clone cells, the S phase fraction was (35.88±2.00)%and (37.00±1.79)%respectively. Overexpression of DNMT3B4 could significantly decrease S phase fraction (P<0.05). The expression of p21 in DNMT3B4 overexpressed cells was increased, but the methylation status of p21 gene promoter was unchanged.Conclusion:Overexpression of DNMT3B4 can inhibit 293A cell proliferation and can facilitate p21 expression.
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Objective To investigate the effects of lovastatin on inducing G1 phase synchromzation in HEC-1-A cells and examine the cell cycle progression after desynchronization.Methods The doubling time of HEC-1-A cells was detected by cell counting Kit-8 assay.To determine the best lovastatin concentration of G1 synchronization,HEC-1-A cells were treated with lovastatin at concentration of 10,20,30 and 40 μmol/L respectively for 1 × doubling time,and the cell cycle was detected by flow cytometry (FCM).To determine the best period of lovastatin treatment to achieve G1 synchronization,HEC-1-A cells were treated with lovastatin at the best concentration for 0.5 × to 2 × doubling time,and the cell cycle was detected every 4 h using FCM.Furthermore,the cell cycle progress of HEC-1-A cells after desynchronization was also observed.Results The doubling time of HEC-1-A cells was 24 h.Treated with lovastatin at concentration of 40 μmol/L for 28 h achieved maximum G1 arrest (87.87±0.70) ％ in HEC-1-A cells.Minimum G1 phase (58.42±0.54) ％ and maximum S phase (33.58±0.62) ％ were observed after desynchronizing for 20 h.Conclusion Maximum G1 synchronization of HEC-1-A cells is induced by lovastatin at concentration of 40 μmol/L for 28 h.The HEC-1-A cells show minimum G1 phase and maximum S phase after desynchronizing for 20 h.
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Objective To study the effect of heat shock protein 40(HSP40) and heat shock protein 70(HSP70) on the aggregate formation of mutant huntingtin (htt) and its toxicity in N2a cells. Methods The effect of the over-expression of HSP40 and HSP70 alone or co-over-expression of them on aggregate formation of transfected mutant htt (containing 150 glutamine repeats, 150Q) in N2a cells was detected by fluorescence microcopy and Western blotting. Cell viabilities were detected by MTT assay. Reactive oxygen species (ROS) production was detected by colorimetric method. Results The over-expression of HSP40 and HSP70 alone, especially the co-over-expression of them, dramatically decreases the formation of 150Q htt aggregates in N2a cells. The numbers of aggregates in each group are as follows ( n = 1 000): about 50% in the group of 150Q htt-expressing alone, about 12% in the group of over-expression of HSP40, about 15% in the group of over-expression of HSP70, about 5% in the group of co-over-expression of HSP40 and HSP70. The result of MTT assay shows that the over-expression of HSP40 and HSP70 alone, especially the co-over-expression of them, dramatically increases cell viabilities ( P<0.01, n =3) and reduces the production of ROS ( P<0.01, n =3). Conclusion HSP40 and HSP70 can increase cell viabilities of 150Q N2a cells via inhibiting the aggregates formation of mutant huntingtin and reducing oxidative stress.
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Huntington's disease (HD) is an autosomal dominant neurodegenerative disease. A cardinal histopathologic feature of HD is the progressive loss of striatal medium spiny neurons. As there is no effective treatment for this fatal disease so far, we explore the therapeutic potential of nortriptyline to identify drugs that might be effective treatments for HD. N548mu [ 1955-128] huntingtin stable ST14A cell line was cultured and incubated in the presence or absence of serial concentrations of nortriptyline. Then R6/2 transgenic HD mice were treated with nortriptyline from five to twenty-one weeks of age. Nortriptyline protected striatal cells expressing mutant huntingtin when shifted to a nonpermissive temperature. Nortriptyline delay the disease onset to 127 d in R6/2 mice as compared with 102 d in saline-treated controls, but nortriptyline did not significantly delay mortality. As a gross marker of lack of systemic toxicity, there was no significant difference in the weight of the treated and control R6/2 mice. The results demonstrate that clinically reasonable doses of one of the identified drugs, nortriptyline, delays disease onset in a mouse model of the disease more than any previously identified compound. The most desirable features of a drug for HD are minimal toxicity and the ability to extend symptom-free living. Nortriptyline appears to be one such good candidate.
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BACKGROUND: Fanconi Anemia (FA) is an autosomal recessive inherited disease, which is characterized by developmental abnormalities, progressive bone marrow failure and a predisposition to cancer. The phenotypes of FA cells show extreme sensitivities towards oxygen and DNA cross linking agents, such as diepoxybutane and mitomycin C (MMC). METHODS: In the current study, retroviruses expressing the FANCA gene were prepared to create the stable cell lines, Hela (cervical carcinoma) and MCF10A (breast). The expression of FANCA protein in the Hela and MCF10A stable cells, following puromycin selection, was checked using Western blot. The difference in the cell growth between the parent and FANCA expressing cells following MMC treatment was checked using the MTT assay. RESULTS: The expression of exogenous FANCA protein in the Hela and MCF10A stable cells was observed using Western blot. The MCF10A cells expressing exogenous FANCA were resistant to MMC concentrations with the range 0.01~1 micrometer compared with the MCF10 parent cells. However, at an MMC concentration of 10 micrometer, there was no difference in the susceptibility between the parent and FANCA expressing MCF10 cells. The Hela cells expressing FANCA showed no resistance at any MMC concentration (0.01~10 micrometer). CONCLUSION: FANCA protein is an important factor for resistance to the cross linking agent, MMC, in MCF10A breast cells, but not in Hela cervical carcinoma cells.
Subject(s)
Humans , Blotting, Western , Bone Marrow , Breast , Cell Line , DNA , Fanconi Anemia Complementation Group A Protein , Fanconi Anemia , Genes, vif , HeLa Cells , Mitomycin , Oxygen , Parents , Phenotype , Puromycin , RetroviridaeABSTRACT
To examine the localization pattern of phospholipase D2 (PLD2) in the pancreatic islet (the islet of Langerhans) depending on species, we conducted a morphological experiment in the rat and guinea pig. Since individual islets display a typical topography with a central core of B cell mass and a peripheral boundary of A, D, and PP cells, double immunofluorescent staining with a panel of antibodies was performed to identify PLD2-immunoreactive cells in the islets PLD2 immunoreactivity was mainly present in A and PP cells of the rat pancreatic islets. And yet, in the guinea pig, PLD2 immunoreactivity was exclusively localized in A cells, and not in PP cells. These findings suggest a possibility that PLD2 is mainly located in A cells of rodent pancreatic islets, and that the existence of PLD2 in PP cells is not universal in all species. Based on these results, it is suggested that PLD2 may play a significant role in the function of A and/or PP cells via a PLD-mediated signaling pathway.
Subject(s)
Animals , Rats , Antibodies , Guinea Pigs , Guinea , Islets of Langerhans , Phospholipases , RodentiaABSTRACT
BACKGROUND: Inactivation in p53 tumor suppressor gene through a point mutation and deletion is one of the most frequent genetic changes found in human cancer, with 50% of an incidence. This high rate of mutation mostly suggests that the gene plays a central role in the development of cancer and the mutations detected so far were found in exons 5 to 8. Mutation of p53 locus produced accumulation of abnormal p53 protein, and negative regulation of cell proliferation and transcriptional activation as a suppressor of transformation were lost . In addition, inhibition of its normal cellular function of wild-type by mutant is an important step in tumorigenesis. METHOD: 4 colon cancer cell lines (SNU C1, C2A, C4, C5) were examined for mutation in exons 5 to 8 of the p53 tumor suppressor gene by PCR-SSCP analysis and expression pattern by western blotting and immunoprecipitation. p53-mediated transactivation ability were examined by CAT assay and base substitution of p53 in SNU C2A cell were detected by DNA sequencing. RESULTS: 1) SNU C2A cell and SNU C5 cell were detected mobility shifts each in exon 5 and exon 7 of p53 gene by the PCR-SSCP method, implicating being of p53 mutation. 2) 3 colon cancer cell lines (SNU C1, SNU C2A, SNU C5) expressed wild type and mutant type p53 protein. 3) In northern blot experiment, SNU C2A and SNU C5 cell expressed high level of p53 mRNA. 4) Results of p53-mediated transactivation in colon cancer cell lines by CAT assay represented only SNU C2A cell has transcriptional activity. 5) DNA sequencing in SNU C2A cell showed missense mutation in codon 179 of one allele, histidine to arginine and wild type p53 in the other allele. CONCLUSION: Colon cancer cell lines showed correlation with mutation in p53 gene and accumulation of abnormal p53 protein. Colon cancer cell SNU C2A retained p53-mediated transactivation as heterozygous p53 with one mutant allele in 179 codon and the other wild-type allele.
Subject(s)
Animals , Cats , Humans , Alleles , Arginine , Blotting, Northern , Blotting, Western , Carcinogenesis , Cell Line , Cell Proliferation , Codon , Colon , Colonic Neoplasms , Exons , Genes, p53 , Genes, Tumor Suppressor , Histidine , Immunoprecipitation , Incidence , Mutation, Missense , Point Mutation , RNA, Messenger , Sequence Analysis, DNA , Transcriptional ActivationABSTRACT
The Pancreatic islets of rats were demonstrated after perfusion with Kanovski- Dithizon by Scanning electronmicroscopy. The results are summed up as follows: Pancreatic islets are closely surrounded by a proper membrane formed by two layers of reticular and collagenous fiber nets. B-cells are polygonal and average 10 ?m in diameter. The surfaces of B-cell are characterized by cytoplasmic projections and blebs, while those of A-cell have few characteristics, A-cells show a momopolar and B-cells a polypolar type of secretions, The inner surfaces of B-cells are characterized by "secretion canaliculus" (insulin canaliculus) and "secretion pore". The secretions canaliculus and secretions pores are the passage through which the secretion Passes into the calpillary net or sinus of the islets.