The Application Value and Strategy of Red Music Culture in Ideological and Political Education in Primary and Secondary Schools

As an important carrier of red culture,red music culture carries the glorious history of revolution,construction,and reform led by the Communist Party of China(CPC),and has significant functional value in cultivating students’ideals,values,and cultural identity,as well as patriotic consciousness and national pride.However,the integration of red music culture into the ideological and political education of primary and secondary schools faces the dilemmas of low cultivation awareness,insufficient excavation of resources,and lack of optimization of atmosphere and field.In view of these problems,the strategies of enhancing cultivation awareness,excavating the resources in-depth,and creating a positive atmosphere and field provide new ideas and methods for ideological and political education in primary and secondary schools.

Establishment and evaluation of the primary cultured tibial osteoblast model of broiler chicks

Osteoblasts are considered as a major factor contributing to bone development and mineralization,however,few studies have been done to establish and evaluate the primary cultured tibial osteoblast model of broiler chicks.Therefore,in the present study,two experiments were conducted to establish and evaluate the primary cultured tibial osteoblast model of broiler chicks.In experiment 1,osteoblasts were isolated from the tibia of one-day-old Arbor Acre male broiler chicks using the explant method and identified through the cell morphology,alkaline phosphatase(ALP)and alizarin red staining.Experiment 2 was carried out to evaluate the vitality and mineralization of primary cultured tibial osteoblasts of broilers on days 4,8,12,16,20,24,28 and 32 after incubation,respectively.The results from experiment 1 demonstrated that primary cultured tibial osteoblasts of broilers showed a spindle-shaped,triangular or polygonal morphology.More than 95%of the cells were stained blue-black after ALP staining,and mineralized nodules were formed after 4 days of continuous incubation.In experiment 2,lactate dehydrogenase(LDH)activity stayed at a relatively stabilized level although incubation time affected(P=0.0012)it during the whole culture period.Additionally,incubation time affected(P≤0.0001)the number and proportion of the area of mineralized nodules.They increased linearly and quadratically(P<0.04)with the increase of incubation time,and remained at a stabilized level from 24 to 32 days of incubation.The estimates of the optimal incubation time were 17 and 26 days based on the best fitted broken-line or quadratic models(P<0.0001)of the number and proportion of the area of mineralized nodules,respectively.These results indicate that the primary cultured tibial osteoblast model of broilers has been established successfully by the explant method,and it showed typical osteoblast morphology and characteristics of ALP activity and mineralization,and could maintain a relatively stabilized vitality from 4 to 32 days of incubation;and the optimal incubation time of primary tibial osteoblasts was 17 to 26 days.Therefore,it could be used to further study the underlying mechanisms of bone development and mineralization of broiler chicks.

Effects of Hypoxia on the Growth and Development of the Fetal Ovine Hepatocytes in Primary Culture

Objective To investigate the development and characterizations of the hepatocytes isolated from fetal ovine and to determine the effect of hypoxia on their growth and metabolism.Methods Fresh hepatocytes were isolated from the liver of fetal ovine at late gestation, cultured in specific media, and exposed to normoxia(21% O2) or hypoxia(2% O2).The cellular characteristics and population purity were identified by immunocytochemistry and flow cytometry(FCM).The effects of hypoxia on cell cycle and apoptosis of the hepatocytes were evaluated by FCM, whereas the cellular ultrastructure changes were examined with a transmission electron microscope.Results The cell purity of hepatocytes was over 95%.Under hypoxia exposure, the hepatocytes showed a gradual increase in proportion at the S phase and in proliferative index, followed with a compatible increase in apoptosis and progressively decreased cell viability.Additionally, the organelles of the hepatocytes demonstrated dramatic changes, including swelling of mitochondria, disorder in cristae arrangement, expansion of endoplasmic reticulum, and a large number of circular lipid droplets emerging in the cytoplasm.Conclusion Fetal ovine hepatocytes could be primarily cultured in a short-term culture system with a high purity of over 95% and with their preserved original characteristics.Hypoxia could induce changes in ultrastructural and inhibit the proliferation of cultured fetal ovine hepatocytes through apoptotic mechanisms.

Effects of Different Culture Condition in vitro on Growth of Cashmere Goat Primary Hair Follicles

[Objective] The aim of this study is to lay a foundation for illustrating the biological characteristics and growth regulation mechanism of hair follicles.[Method]Cashmere goat primary hair follicles were separated under aseptic condition and cultured in serum-free DMEM and serum-free Williams E media respectively;subsequently,the growth rate and morphological changes were observed under the inverted microscope.[Result]Hair follicles cultured in serum-free DMEM media showed a growth rate of 0.034 mm/d during the first 3 days,whose structure and morphological characteristics could maintian a stable status for a long time in the growth process.Hair follicles grew much faster in the serum-free Williams E media with a growth rate of 0.077 mm/d during the first 3 days.[Conclusion]There were significant differences(P<0.05)between the growth of cashmere goat hair follicles cultured in the 2 kinds of media.Serum-free Williams E medium was superior to serum-free DMEM medium.

Primary Culture of Bovine Mammary Epithelial Cells

[ Objective] To investigate the feasibility of the primary culture of bovine mammary epithelial cells in biochemical incubator. [ Method] In vitro, bovine mammary epithelial cells were isolated and cultured by the tissue explant method in order to investigate the optimal culture conditions. The morphology observation and identification of the cultured cells were performed by inverted microscope observation, Giemsa staining and cytokeratin immunohistochemistry. [ Result] Observed with inverted microscope, most of the bovine mammary epithelial cells were polygonal and displayed typical slabstone-like appearance. As it can be seen from cell staining results, the cell body was big and the nucleus was stained dark blue and was round or oval in shape, with clearly visible nucleoli, generally 2 -4 nucleoli. The tissue-specific expression of cytokeratin 14 and cytokeratin 18 genes in mammary epithelial cells was identified by cytokeratin immunohistochemistry. [ Conclusion] Primary bovine mammary epithelial cells were successfully cultured in biochemical incubator.

Effects of Estradiol on Cashmere Goat Primary Hair Follicles Cultured in vitro

[Objective] The aim of this study was to preliminarily explore the effects of estradiol on morphology and growth of cashmere goat primary hair follicles. [Method] Cashmere goat primary hair follicles were cultured in serum-free Williams E media supplemented with different doses of 17 β-E2 (0, 0.1, 1.0, 10.0, 100.0 nmol/L), and their growth rates and morphological changes were observed. [Result] The growth rate of 0.1 nmol/L 17 β-E2 group was quite comparable with that of the control group(0 nmol/L), but the 17 β-E2 with concentrations of 1.0, 10.0 and 100.0 nmol/L displayed different degrees of inhibition on the growth of hair follicles. Different morphological changes of hair follicles could also be discovered in different concentration treatments. [Conclusion] The study laid a certain foundation for exploring the regulation mechanism of estrogen on growth of cashmere goat hair follicles.

Protective Effects of Quercetin on Cadmium-induced Cytotoxicity in Primary Cultures of Rat Proximal Tubular Cells

Objective To investigate the protective effects of quercetin on cadmium-induced cytotoxicity in primary cultures of rat proximal tubular （rPT） cells. Methods Primary cultures of rPT cells undergoing exponential growth were incubated with 1.0 ug/mL quercetin and/or cadmium （2.5, 5.0 umol/L）, in a serum-free medium at 37℃ at different time intervals. Commercial kits were used and flow cytometric analyses were performed on rPT cell cultures to assay apoptosis and oxidative stress. Results Exposure of rPT cells to cadmium acetate （2.5, 5.0 umol/L） induced a decrease in cell viability, caused an increase in apoptotic rate and apoptotic morphological changes. Simultaneously, elevation of intracellular reactive oxygen species, malondialdehyde and calcium levels, depletion of mitochondrial membrane potential and intracellular glutathione, and inhibition of Na＋, K＋ -ATPase, Ca2＋ -ATPase, glutathione peroxidase （GSH-Px）, catalase （CAT）, and superoxide dismutase （SOD） activities were revealed during the cadmium exposure of rPT cells. However, simultaneous supplementation with 1 ug/mL quercetin protected rPT cells against cadmium-induced cytotoxicity through inhibiting apoptosis, attenuating lipid peroxidation, renewing mitochondrial function and elevating the intracellular antioxidants （non-enzymatic and enzymic） levels. Conclusion The present study has suggested that quercetin, as a widely distributed dietary antioxidant, contributes potentially to prevent cadmium-induced cytotoxicity in rPT cells.

Isolation and primary culture of rat hepatocytes

Objective: To find out an optimal condition for isola-tion and primary culture of hepatocytes.Method: Rat hepatocytes were isolated by a two-stepcollagenase perfusion, and cultured in hepatozyme-SFM. The reduction of MTT to formazan salt was ex-amined. Supernatant medium was collected for analy-sis of alanine aminotransferase（ALT） and ureagene-sis.Results: The two-step collagenase perfusion yielded39±12×10;cells/g liver tissue with a viability of88%±2%. Fine morphology and stable urea synthesisfor one week could be achieved when hepatocytes werecultured in Hepatozyme-SFM.Conclusion: High yield of hepatocytes can be isolatedwith two-step collagenese perfusion. Hepatozyme-SFM is suitable for sustained growth of hepatocytes.

Oxidative damage of primary cultured hippocampal neurons Does androgen have an antagonistic effect?

BACKGROUND： Evidence illustrates that androgen has a neuroprotective role. However, whether androgen also has the protective effect on hippocampal neurons during free radical mediated injury remains unclear. OBJECTIVE： To investigate the neuroprotective effect of androgen on hippocampal neurons during free radical damage. DESIGN, TIME AND SETTING： A controlled in vitro experiment was performed at the Department of Human Anatomy, Cell Culture Lab, and Neuroendocrinology Lab, Basic Medical School, Hebei Medical University from February to June 2009. MATERIALS： Testosterone was provided by Tianjin Jinyao Amino Acid Company, China. METHODS： Primary cultured neurons from 24 Sprague Dawley rats were randomly assigned into four groups： control, H202, testosterone, and testosterone （pre-added） plus H2O2 groups. MAIN OUTCOME MEASURES： The positive cell ratio of microtubule associated protein-Ⅱ and neuron specific enolase was determined by immunocytochemistry. Neuronal morphology was observed by hematoxylin-eosin staining and Nissl staining. Cell vitality and viability were determined using an inverted phase contrast microscope. The content of nitric oxide synthase, malondialdehyde, and superoxide dismutase were measured with a spectrophotometer. RESULTS： As compared with the control group, cell vitality and viability, and superoxide dismutase level were significantly decreased in the H202 group （P 〈 0.05）, while nitric oxide synthase and malondialdehyde levels were significantly increased （P 〈 0.05）. Neuronal vitality and viability as well as superoxide dismutase level in the testosterone plus H2O2 group were significantly greater than in the H2O2 group （P 〈 0.05）, and nitric oxide synthase and malondialdehyde levels were significantly less than in the H2O2 group （P〈 0.05）. CONCLUSION： Androgen partially reversed H2O2-induced neuronal damage and protected neurons.

Establishment of primary cultures of craniopharyngioma cells

Craniopharynigoma samples were collected from 36 patients. Out of the 36 samples, 29 achieved successful sub-culturing, with a success rate of 80.6%. Immunohistochemistry staining showed that cytokeratin-7 was positively expressed in the cytomembrane and cytoplasm of craniopharyngioma cells at 6-8 passages, confirming that all cultured cells were squamous epithelial cells. The doubling time of craniopharyngioma cells was 3 days, as confirmed by the 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide assay. In this study, craniopharyngioma cells cultured in vitro were established; however, establishment of immortalized craniopharyngioma cell lines requires further research.

Transplantation of primary cultured embryonic mesencephalic neural precursor cells for treating Parkinsonian rats

BACKGROUND： Choosing proper donor cells is one of keys in experimental and clinical studies on cell replacement therapy （CRT） for treating Parkinson disease （PD）. Embryonic mesencephalic precursor cells （MPCs） can stably differentiate into dopaminergic neuron after in vitro proliferated culture. As compared with embryonic stem cell and neural stem cell strains, cell composition of embryonic MPCs after primary culture is also the most close to that of embryonic mesencephalic ventral cell suspension without proliferated culture. Successful experience accumulated in the latter suggests that primary cultured embryonic MPCs might be the most potential donor cells in clinical application with CRT for treating PD so far. OBJECTIVE： To investigate the feasibility of primary cultured embryonic precursor cells cultured primarily as donor cells in CRT for treating PD in rats. DESIGN ： A randomized and controlled trial taking SD rats as experimental animals.SETTING： Department of Neurosurgery, Huashan Hospital Affiliated to Fudan University.MATERIALS： This experiment was carried out at the Institute of Neuroscience, Shanghai Institute for Biological Science, Chinese Academy of Sciences from July 2003 to June 2004. Totally 26 female SD rats, with body mass of 200 to 220 g, were provided by Shanghai Experimental Animal Center of Chinese Academy of Sciences. METHODS ： Stereotaxic injection of 6-hydroxydopamine into the medial forebrain bundle were perfored to develop PD model rat. Among 26 SD rats, 20 rats achieved a more than 5 turns/min in apomorphine induced rotation test, reaching the standard of PD model rats. Immunohistochemical detection was performed on 1 out of 20 model rats after execution, and the other 19 rats were randomly divided into control group （n=5）, sham transplantation group （n=5）and cell grafted group （n=9）. Primary cultured E12 MPC cell suspension （1.2×10^11 L^-1）were used as donor cells. 4μL primary cultured E12 MPC cell suspension prepared freshly was injected into the lesioned corpus striatum of rats in cell grafted group, and 4μL D-Hank＇s solution was injected in sham transplantation group in the same way. There was no injection in control group. Apomorphine-induced rotation rate of PD rats were recorded respectively in cell grafted group and sham transplantation group pre-operation （initial value） and at postoperative 2, 4, 6 and 16 weeks. Apomorphine-induced rotation rate of PD rats was recorded in control group at postoperative 2 months （initial value） and following 2,4,6 and 16 weeks. To determine TH antigen with immunohistological ABC method （DAB developing） at 6 months post-transplantation to investigate the differentiation and survival of donor cells in the host body.MAIN OUTCOME MEASURES： Apomorphine-induced rotation behavior before and after transplantation and the survival and differentiation of implanted cells in the host body at 6 months post-transplantation. RESULTS： Among 19 model rats, one rat died after transplantation respectively in the cell grafted group and sham transplantation group; finally 17 model rats entered the stage of result analysis. Relative apomorphine-induced rotation rate was significantly decreased in the cell grafted group as compared with that before transplantation , with significant difference （P 〈 0.01 .P 〈 0.05）;the mean value of relative apomorphine-induced rotation rate was significantly decreased at postoperative 16 weeks in cell grafted group as compared with that of corresponding relative rotation rate in control group , also with significant difference （P 〈 0.05）.Immunohistological results showed that donor cells could differentiate into large and multi-polar dopaminergic neurons in the host body. CONCLUSION ： Primary cultured embryonic MPCs can be used as the donor cells in CRT for treating PD.

Bis(7)-Tacrine, a Promising Anti-Alzheimer's Agent,Attenuates Glutamate-Induced Cell Injury in Primary Cultured Cerebrocortical Neurons of Rats

The effects of bis(7) tacrine, a novel dimeric acetylcholinesterase (AChE) inhibitor, on glutamate induced cell injury were investigated in primary cerebral cortical neurons of rats. Exposure of cultured neurons (12 days after plating) to 0.5 mmol/L glutamate for 30 min resulted in significant cell damage. Pretreatment with bis(7) tacrine (0.03 1.0 μmol/L) reduced the glutamate induced neurotoxicity in a concentration dependent manner and the maximal response was seen at 1 μmol/L with approximately 30% protection. A receptor binding assay showed that bis(7) tacrine can completely displace MK 801 binding to rat cortical membrane with an IC 50 of 0.57 μmol/L. These findings suggest that bis(7) tacrine can directly interact with N methyl D aspartate receptor channel complex, which may contribute to the inhibitor's protective effects against glutamate induced excitotoxicity. Thus, it is possible that anti glutamate/anti AChE synergism is responsible for potentially better Alzheimer's therapy of bis(7) tacrine relative to tacrine.

Manganese enhances the expression of the manganese superoxide dismutase in cultured primary chick embryonic myocardial cells

In the present study, the effect of manganese（Mn） on antioxidant status and the expression of the manganese superoxide dismutase（MnSOD） gene in cultured primary myocardial cells collected from the chick embryos was investigated. The hypothesis that Mn supplementation would enhance the expression of MnSOD in cultured primary myocardial cells of chick embryos was tested. Eggs collected from Mn-depleted Arbor Acres laying breeder hens were incubated for 10 days and then myocardial cells were isolated and cultivated for 8 days. The embryonic myocardial cells on day 6 were treated with Mn in the cell culture medium at different time points when the proportion of cells showing spontaneous contraction was over 95% after the 3-day primary culture. A completely randomized design involving a 3 Mn levels（0, 0.5 and 1.0 mmol L^（-1））×3 incubation time points（12, 24 and 48 h） factorial arrangement of treatments（n=6） was used in the current experiment. The results showed that MnSOD activity and m RNA expression level were induced by Mn and increased with incubation time, which supported the hypothesis that Mn would enhance the expression of the MnSOD gene, and thus might protect myocardial cells from oxidative stress during the chick embryonic development.

Primary Culture of Alveolar Epithelial Type Ⅱ Cells and Its Bionomic Study

To establish a better method of primary culture for alveolar epithelial type Ⅱ cells （AEC Ⅱ ） and to study its bionomics, alveolar epithelial type Ⅱ cells were isolated by digestion with trypsin and collagenase, which were then purified by plated into culture flask coated with rat immunoglobulin （i The purified AEC Ⅱ were identified by alkaline phosphatase staining, electron mi- croscopy, immunocytochemical staining of pulmonary surfactant protein A （SPA）. The SPA expression and transfection characteristics were compared with those of A549 cell line. The results showed that AEC Ⅱ could be isolated by digestion with trysin and collagenase and purified by adhesive purification by using IgG, with a yield of about 2-3 × 10^7, and a purity of about 75%-84 %. Cells could be quickly identified with AKP staining. AEC Ⅱ were different from A549 cell line in terms of SPA expression and transfection characteristics. It is concluded that adhesive purification with IgG can improve the purity of AEC Ⅱ, and AKP staining is simple in cell identification. AEC Ⅱ can not be completely replaced by A549 cells in some studies because the differences between them, such as SPA expression.

<i>N</i>–nitrosodiethylamine cytochrome P450 induction and cytotoxicity evaluation in primary cultures of rat hepatocytes

The primary routes of potential human exposure to N-nitrosodiethylamine (NDEA) are ingestion, inhalation, and dermal contact. Air, diet and smoking contribute to potential human exposure at levels of a few μg of NDEA/day. Potential exposure depends on the ability of the nitrosamines to migrate from the product into the body. The first step in the metabolic degradation of NDEA by cytochrome oxidase (CYPs) enzymes is the introduction of a hydroxyl group and in human esophage and liver CYP2A3 and CYP2E1 participate on this metabolism. Measuring cytotoxicity in female rat primary hepatocytes cultures, were used to understand the CYP induction and metaboli-zation correlated with low NDEA concentrations. We observed that NDEA at different concentrations in the absence of CYPs inducers, was able to induce CYP2B1, CYP2B2, CYP2E1, CYP3A1 and CYP4A3. A positive NDEA synergistic effect on the levels of mRNA, was observed in the presence of pyrazole (300 μM) for CYP2B1 and CYP2B2 and for pregnenolone 16- carbonitrile (0.15 μM) for CYP2E1. Negative NDEA synergistic effects were observed for ethanol (0.3%) for CYP3A1, pyrazol (300 μM) for CYP2A1 and CYP2E1, and phenobarbital (1 mM) for CYP2A1. These facts are extremally important once that these metabolites can be directly related to the primary DNA lesions. We consider that studies to elucidate the biological factors that determine the shape of the dose-response curve are crucial for low-dose extrapolations of risk.

The study of selective primary culture and determination of a breast cancer cell line in vitro

Objective The successful establishment of a tumor cell bank is based on the premise that the target cells can be cultured by a legitimate approach.In this experiment,we used primary culture to select and detect breast cancer cells in vitro,which can provide experimental ideas and methods for the establishment of a living tumor tissue cell bank.Methods Fifty-two specimens were collected over a two-year period from people with breast cancer who needed surgical treatment in our hospital.Cells were isolated and used to establish successful cell culture.Cell activity and cell purity were measured before liquid nitrogen cryopreservation.Results(1)At the initial culture stage,cells grew with adherence.Cell multiplication could be seen after the cell medium was exchanged three times.Cell viability was above 86%,while the viability of the target cells was above 75%,as detected by hematoxylin and eosin(HE)staining.(2)The number of breast cancer cells decreased,while the number of fibroblasts increased after five rounds of passage.(3)The success rate was 73.08%,which did not include polluted cells and those that were not successfully cryopreserved.Conclusion(1)breast cancer cells could be selected from primary culture in vitro through an appropriate method.(2)Exchange of the cell medium and further cell passage improved cell multiplication.(3)The experimental results could be monitored using trypan blue and HE staining.(4)The success of breast cancer cell culture in vitro could be used as a reference for other cell culture,so as to establish a tumor tissue cell bank.

Cytotoxicity of Modified Nonequilibrium Plasma with Chlorhexidine Digluconate on Primary Cultured Human Gingival Fibroblasts

The aim of this study was to investigate the cytotoxicity of modified nonequilibrium plasma with chlorhexidine digluconate（CHX） on human gingival fibroblasts（HGFs）, and to evaluate the biosecurity of modified nonequilibrium plasma with 2% CHX as a new method of root canal treatment. Tissue samples taken from human gingiva were primarily cultured and passaged. Cells from passages 3–7 were used. HGFs were treated by modified nonequilibrium plasma with 2% CHX for 0 min（control group）, 30 s, 1 min, 1.5 min, 3 min, 5 min, and 10 min, respectively, and then they were incubated for 0, 24, and 48 h. After that, cell counting kit-8（CCK-8） assay was applied to analyze the cytotoxicity of modified nonequilibrium plasma with 2% CHX on HGFs. There was no significant difference between the 0 h group treated with the modified nonequilibrium plasma for 1 min and the control group（P〉0.05）. However, there were significant differences between all the other treated groups and the control group（P〈0.05）. When treated for 1.5 min or shorter, the cell viability was obviously increased; while treated for 3 min or longer, it was obviously reduced. Moreover, when successively cultured for 0, 24, and 48 h, cell viability was decreased at first and then increased in the 3-min-treated and 5-min-treated groups. The modified nonequilibrium plasma with 2% CHX was of no influence on cell viability in 1.5 min treatment, and it could be safely used on root canal treatment.

Primary culture and identify of cerebral cortical astrocytes from Sprague-Dawley rats

OBJECTIVE To establish a method for primary cultured and iden-tified Sprague-Dawley(SD) rats cerebral cortical astrocytes. METHODS Cerebral co-rtex of SD neonatal rats within 24 h was taken with stereo microscope and was cut topieces(1 mm^3),digested by Accutase and 0.1% DNAase(37℃,15 min),anddispersed cell suspension was made by mechanical method and filtered. The fibroblast cells and microglia were removed through differential adhesion and sha-ke. Passaged cells were identified by immunofluorescent with anti-Glial fibrillaryacidic protein(GFAP) antibody. RESULTS The astrocytes of rats cerebral cortex were cultured in this method,which had a large number of cells,good activity,high purity,abundant and elongated cell processes,and were interwoven into a network,showing a typical and good growth state. The third generation of the cel s comprised >95% astrocytes. CONCLUSION This simple and reliable cultivation method of astrocyte from rat cerebral tissue is established with high purity,and in a good growth condition.

Effects of L-THP on Ca^(2+) Overload of Cultured Rat Cardiomyocytes during Hypoxia and Reoxygenation

The effects of L-tetrahydropalmatine (L-THP) on the cultured rat cardiomyocytes during hypoxia and reoxygenation and the mechanism of L-THP treating reperfusion-arrythmias were stud- ied. The concentration of intracellular free calcium ([Ca2+]i) of single cultured ventricular myocyte was determined by using EPC-9 light-electricity measurement system. It was found that L-THP (100μmol/L) could reduce the [Ca2+]i augmentation in single cultured ventricular myocyte during hypoxia and reoxygenation. Verapamil (10 μmol/L ) had the similar effect. It was concluded that L- THP could inhibit the Ca2+ overload of cultured rat cardiomyocytes during hypoxia and reoxygena- tion.

Effect of the gene silencing of phosphorus transporters on phosphorus absorption across primary cultured duodenal epithelial cell monolayers of chick embryos

The aim of the study was to investigate whether phosphorus(P) transporters, type IIb sodium-dependent phosphate cotransporter(NaP-IIb) and inorganic phosphate transporter 2(PiT2), were directly involved in P absorption across primary cultured duodenal epithelial cell monolayers of chick embryos. The siRNAs against NaP-IIb or PiT2 were designed, synthesized and transfected into primary cultured duodenal epithelial cells of chick embryos. Then, the inhibitory efficiency of siRNAs against NaP-IIb or PiT2 was analyzed, and the most efficacious siRNAs were selected to be used for subsequent P absorption experiments. Briefly, primary cultured duodenal epithelial cells of chick embryos were transfected with either NaP-IIb or PiT2 siRNAs and grown in confluent monolayers on transwell plates. The untransfected or transfected cell monolayers were then incubated in an uptake medium containing 0 or 0.25 mmol L^(–1) of P as KH_(2) PO_(4) to measure the P absorption across duodenal epithelial cell monolayers. The results showed that among the siRNAs designed, si-1372 and si-890 were demonstrated to be the most effective in inhibiting the NaPIIb and PiT2 expressions, respectively. Supplemental P increased(P=0.065) the protein abundance of PiT2 and enhanced(P<0.0001) P absorption in primary cultured duodenal epithelial cell of chick embryos. Furthermore, NaPIIb silencing decreased(P=0.07) P absorption across duodenal epithelial cell monolayers, while PiT2 silencing had no effect(P=0.345). It is concluded that the NaP-IIb, but not PiT2, might be directly involved in the P absorption of chick duodenal epithelial cells.