Age-Associated Changes in the Vascular Renin-Angiotensin System in Mice

Yoon, Hye Eun,Kim, Eun Nim,Kim, Min Young,Lim, Ji Hee,Jang, In-Ae,Ban, Tae Hyun,Shin, Seok Joon,Park, Cheol Whee,Chang, Yoon Sik,Choi, Bum Soon Hindawi Publishing Corporation 2016 Oxidative medicine and cellular longevity Vol.2016 No.-

<P><I>Background</I>. This study evaluated whether the change in the renin-angiotensin system (RAS) is associated with arterial aging in mice.<I> Methods</I>. Histologic changes and expressions of transforming growth factor-<I>β</I> (TGF-<I>β</I>), collagen IV,<I> fibronectin</I>, angiotensin II (Ang II), angiotensin-converting enzyme (ACE), angiotensin-converting enzyme 2 (ACE2), angiotensin II type 1 receptor (AT1R), angiotensin II type 2 receptor (AT2R), prorenin receptor (PRR), Mas receptor (MasR), endothelial nitric oxide synthase (eNOS), NADPH oxidase 2 and oxidase 4 (Nox2 and Nox4), 8-hydroxy-2′-deoxyguanosine (8-OHdG),<I> 3-nitrotyrosine</I>, and superoxide dismutase 1 and dismutase 2 (SOD1 and SOD2) were measured in the thoracic aortas from 2-month-old, 12-month-old, and 24-month-old C57/BL6 mice.<I> Results</I>. Twenty-four-month-old mice showed significantly increased aortic media thickness and expressions of TGF-<I>β</I>, collagen IV, and fibronectin, compared to 2-month-old and 12-month-old mice. The expressions of PRR, ACE, and Ang II, and AT1R-positive area significantly increased, whereas expressions of ACE2 and MasR and AT2R-positive area decreased with age. The expressions of phosphorylated serine<SUP>1177</SUP>-eNOS, SOD1, and SOD2 decreased, and the 8-OHdG-positive area and the 3-nitrotyrosine-positive area increased with age. The expression of Nox2 significantly increased with age, but that of Nox4 did not change.<I> Conclusions</I>. The enhanced PRR-ACE-Ang II-AT1R axis and reduced ACE2-MasR axis were associated with arterial aging in mice. </P>

건강신념모델에 근거한 노인 대상 식품안전·영양교육 프로그램 효과 평가

최정화(Jung-Hwa Choi),이은실(Eun-Sil Lee),이윤진(Yoon-Jin Lee),이혜상(Hye-Sang Lee),장혜자(Hye-Ja Chang),이경은(Kyung-Eun Lee),이나영(Na-Young Yi),안윤(Yoon Ahn),곽동경(Tong-Kyung Kwak) 한국식품영양과학회 2016 한국식품영양과학회지 Vol.45 No.9

노인은 면역취약집단으로 다른 인구 집단보다 만성질환과 식품매개 질병에 걸릴 위험이 크며 식행동은 오랜 세월 굳어져 왔기 때문에 변화하기가 쉽지 않다. 노인을 대상으로 건강신념모델을 적용하여 식품안전・영양교육 프로그램을 시범 적용하고 그 효과를 평가하였다. 식품안전·영양 시범 교육은 서울 마포, 충북 청주, 경북 의성, 충북 진천의 노인복지관을 이용하는 65세 이상 노인을 대상으로 2011년 7월 28일부터 9월 9일까지 총 5주간 매주 1회, 35~40분씩 교육을 시행하였다. 교육 전후 조사가 완료된 최종 연구대상은 교육군이 5회 교육 중 3회 이상 교육에 참여하고 교육 전후 평가를 마친 대상자로 137명, 대조군은 사후 설문조사를 하지 않거나 불성실한 응답자를 제외한 83명으로 총 220명이었다. 교육은 건강신념모델을 적용하여 노인들이 식습관을 변화하지 않을 경우 질병 가능성을 알려 심각성을 인지하도록 하였으며 노인들이 식행동 수정 시 얻게 되는 이들을 알려주고 행동을 실행할 수 있도록 자아효능감을 제공해주고자 하였다. 교육 후 식품안전·영양지식은 모든 항목에서 향상을 보였으며, 식품안전 영역 5문항 중 4문항, 영양 영역 3문항 중 2문항에서는 유의적인 향상을 보였다. 식행동은 교육군에서 ‘고기, 생선류는 조리 시 속까지 완전히 익힌다’를 제외한 모든 항목에서 유의적인 향상을 보였다. 건강신념은 식품안전의 영역에서는 인지된 심각성과 자아효능감, 영양 영역에서는 인지된 민감성, 인지된 장애, 자아효능감에서 유의적인 향상을 보였다. 지식, 식행동, 건강신념 변화량의 상관관계를 분석한 결과 건강신념의 변화량과 식행동의 변화 가능성 간의 유의적인 상관관계를 보였다(P<0.001). 본 연구의 참여 대상자들이 일반 재가 노인보다 복지관에서 봉사하거나 활동하는 노인이었기 때문에 표본의 대표성이 떨어져 결과를 일반화하기에 어려움이 있다. 또한, 교육기간이 5주로 비교적 짧았기 때문에 오랜 기간에 걸쳐 형성된 식행동이 쉽게 변화하거나 개선되기 어려우므로 장기간에 걸친 반복교육이 필요할 것으로 생각한다. 본 연구에서 개발된 교육 프로그램을 향후 보건소나 복지관 등을 통해 지속해서 시행된다면 노인의 식품안전・영양에 대한 인식을 높이고 바람직한 식행동 변화에 긍정적인 기여를 할 수 있을 것으로 생각된다. Most elderly have difficulties in managing food safety and nutrition by themselves. Various nutrition educations for the elderly have been developed, but food safety and nutrition education program and educational tools for the elderly are very limited. The aim of the study was to evaluate a food safety and nutrition education program based on the Health Belief Model (HBM) for the elderly. Education program was implemented for 220 seniors (137 educated group and 83 control group) aged over 65 years at senior welfare community centers. The intervention study was carried out on a weekly basis during each of 5 weeks, and each session lasted about 35 or 40 minutes. The effectiveness of the program was assessed with a questionnaire before and after education. Education program consisted of a 5 week program, and topics were ‘Dietary changes for the elderly"s healthy life’, ‘Prevention of food poisoning in everyday life’, ‘Safe food handling for my health’, ‘Healthy dietary life to prevent chronic disease’, and ‘Safety! nutrition! healthy dietary life’. Education program materials such as slides, handouts, videos, leaflet, and booklets were developed. As a result, there were score improvements in knowledge, dietary behaviors, and health belief after intervention in the intervention group, which were higher than those of the control group. In particular, there was a meaningful interrelation between dietary behavior and health belief (r=0.520, P<0.001). This finding suggests that changing beliefs is very important to make desirable dietary behavioral changes. For this reason, we can conclude HBM theory is an effective model to educate nutrition and food safety for the elderly. Furthermore, food safety and nutrition education programs are implemented and delivered continuously at various settings such as a health center or community welfare center, and those will contribute significantly to enhance perception and change their desirable dietary behaviors for the elderly.

암세포 증식에 대한 YB-1 안티센스 올리고핵산염의 영향

김명성 ( Myung Sung Kim ),이완식 ( Wan Sik Lee ),박창환 ( Chang Hwan Park ),주영은 ( Young Eun Joo ),김현수 ( Hyun Soo Kim ),최성규 ( Sung Kyu Choi ),유종선 ( Jong Sun Rew ),정영도 ( Young Do Jung ),김세종 ( Sei Jong Kim ),안봉환 대한내과학회 2006 대한내과학회지 Vol.71 No.3

목적: YB-1은 PCNA, DNA 중합효소 및 MDR 유전자 등의 전사인자로 작용한다. YB-1 유전자는 정상 어른의 간에서는 발현되지 않지만 태아의 간이나 재생 중인 간에서는 발현이 현저히 증가되어서 세포의 증식과 밀접한 관련이 있음이 보고되었다. 본 연구에서는 YB-1 유전자의 안티센스 올리고핵산염을 이용하여 YB-1의 발현을 억제함으로써 암세포 증식을 차단 할 수 있는지를 실험하고 암치료를 위한 유전자 요법으로서의 가능성을 알아보았다. 방법: 세포주로는 Chang liver, HepG2, CT-26 세포를 사용하였고, 사람의 정상세포로는 섬유아세포와 내피세포가 혼재된 조직을 사용하였다. YB-1 유전자의 안티센스 올리고핵산염으로는 YB-1 cDNA의 변역 시작 부위에 상보적인 21mer 올리고핵산염을 제작하여 사용하였다. 세포의 성장은 MTT assay를 이용하였고, 유전자 발현은 Northern blot으로 분석하였으며, 세포주기 변화는 propidium iodide로 염색하여 유식세포분석기로 분석하였다. 동물실험에서는 CT-26 세포를 1.0×10(5)개씩 Balb/c 생쥐의 피하에 접종하여 종양을 유도하였다. 종양이 유도된 Balb/c 생쥐에 YB-1 안티센스 올리고핵산염을 꼬리정맥이나 종양조직에 주사한 후 종양의 크기를 측정하여 종양억제 효과를 관찰하였다. 결과: YB-1 안티센스 올리고핵산염은 CT-26 세포에서는 50 nM 이상 농도에서 Chang liver와 HepG2 세포에서는 10 nM 이상 농도에서 세포주의 성장을 강하게 억제하였지만 정상 조직세포의 성장에는 아무런 영향을 미치지 않았다. 안티센스 올리고핵산염을 DOTAP에 담지한 경우 세포성장 억제에 미치는 효과가 안티센스 올리고핵산염 단독 처치 보다 강하였다. 이때 YB-1의 발현은 증식이 억제된 세포주(Chang liver 및 CT-26)에서는 감소하였으나 정상조직세포에서는 변화가 없었다. 증식이 억제된 세포주에서 세포주기를 살펴보면 초기에 S phase가 감소함을 관찰 할 수 있었다. 꼬리정맥이나 종양조직에 YB-1 안티센스 올리고핵산염을 주입 시 종양의 크기가 유의하게 감소하였다. 결론: 이상의 실험 결과 YB-1 안티센스 올리고핵산염은 암세포의 성장을 저해하며 종양 동물모델에서 종양의 성장을 억제할 수 있음을 시사하였다. Background: Human YB-1 is a transcription factor that binds to the inverted CCAAT box in the promoter region of a variety of genes such as PCNA, DNA polymerase and MDR. In this study we evaluated the effect of YB-1 antisense oligonucleotides on tumor cell growth. Methods: Chang liver, HepG2 and CT-26 cells were cultured as immortalized cell lines. The MTT (3-[4,5-dimethylthiazol-2-yl] 2,5-diphenyltetrazolium bromide) assay, Northern blot and flow cytometric analyses were used to determine cell growth, gene expression and cell cycle changes. In an animal model, CT-26 cells were injected into Balb/c mice to induce tumor; YB-1 antisense oligonucleotides were injected into the tail vein or tumor tissue of the mice; change of tumor size was then measured. Results: Phosphorothioated YB-1 antisense oligonucleotides suppressed the proliferation of the immortalized liver cells (Chang liver cells) and a variety of cancer cells (HepG2 and CT-26 cells); however, it did not inhibit normal cell growth. The DOTAP/antisense oligonucleotide mixture showed stronger effects on cell proliferation than did the antisense oligonucleotide alone. The YB-1 antisense oligonucleotide decreased specific expression of the YB-1 mRNA in the immortalized cancer cell lines. Flow cytometric analysis revealed that the inhibition of cell proliferation might have been due to a decrease in the S phase of the cell cycle. We found that in an animal tumor model, the administration of the YB-1 antisense oligonucleotide, in the vein or tumor tissues, decreased the tumor size significantly. Conclusions: These results suggest that the YB-1 antisense oligonucleotide may inhibit growth of a variety of cancer cells.(Korean J Med 71:293-301, 2006)

Rheology of Decamethylceclopentasiloxane (cyclomethicone) W/O Emulsion System

Choi, Min-Hyung,Jeong, So-Ra,Nam, Sang-In,Shim, Sang-Eun,Chang, Yoon-Ho The Polymer Society of Korea 2009 Macromolecular Research Vol.17 No.12

A highly dispersed W/O emulsion of silicone oil (cyclomethicone)/water system was prepared with a nonionic surfactant. The surface and interfacial tension between the oil and water were characterized in terms of the droplet size distribution and viscosity change of the emulsion. When the dispersed phase concentration was relatively high, the viscosity of the emulsion was rapidly increased and the droplet size of the emulsion was decreased. The rheological behavior of the emulsion system showed non-Newtonian and shear thinning phenomena depending upon the content of the dispersed phase. The droplet size of the emulsion was decreased with increasing surfactant content and water concentration. The relative viscosity of the emulsion was better predicted with the Choi-Schowalter model than with the Taylor model. The value of the complex modulus increased with increasing surfactant concentration. The linear viscoelastic region was expanded with a dispersed phase concentration. According to the change in the viscosity, the behavior was classified into three distinct regions: [I] linear viscoelastic, [II] partially viscoelastic, and [III] viscous. The creep/recovery behaviors in each region were characterized.

Poly(ether-b-ester) Thermoplastic Elastomers : Synthesis and Properties

Choi, Sei Young,Choi, Kyo Chang,Lee, Eun Kyoung 청주대학교 산업과학연구소 2001 産業科學硏究 Vol.18 No.2

디메틸 테레프탈레이트 (DMT), 1,4-부탄디올 (1,4-BD) 그리고 분자량이 2000인 폴리테트라 메틸렌에테르 글리콜 (PTMG)로 부터 폴리에스터계 열가소성 탄성체 (TPEE)를 합성할 수 있었다. 고온에서의 열적 안정성및 기계적 물성을 증대시킬 목적으로 열처리를 하였으며, 이에 따라 결정성 hard segmen의 보다 규칙적인 배열로 인한 향상된 물성을 확인 할 수 있었다 본 실험에서 합성된 공중합체는 soft segment의 함량이 증가함에 따라 융점및 결정화도가 감소함을 보여 주었다. 기계적 물성의 경우, soft segment의 함량이 35%인 공중합체가 soft segment와 hard segment간 최적의 물리적 가교점 형성으로 인하여 가장 우수함이 관찰 되었다. The poly(ether-b-ester) thermoplastic elastomers (TPEEs) were synthesized by melt polymerization using dimethyl terephthalate (DMT), 1,4-butanediol (1,4-BD) and poly (tetramethylene ether) glycol (PTMG) in the molecular weight of 2000 (g/㏖). The copolymers were prepared with a constant PBT mass ratio of 100; the content of PTMG was changed. To improve thermal stability at elevated temperatures and mechanical properties, the final copolymers were annealed. The chemical structure and thermal properties of them were examined by utilizing FT-IR and DSC. For a better understanding of the structure and property relationships, SEM and a three-point loading system (UTM) were used. The rheological characteristics of them involving the changes of viscosity with the increasing shear rate were also studied. From this experiment, it was shown that as the proportion of soft segment increases melting temperature and degree of crystallinity of TPEEs decrease constantly and the lamella structure was found to be less fine in shape. Meanwhile, in case of flexural strength and flexural elastic modulus, 35-PTMG^(2000) indicates the highest values. As the shear rate increases thixotropy (shear thinning), one of the non-newtonian flows, is found. The results of melt flow properties seem tc be similar to those of strength and elastic modulus in flexure, and 35-PTMG^(2000) shows the viscosity higher than others. A11 of the properties of the copolymers synthesized in this work were found to be improved by thermal treatment.

6-OHDA가 흰쥐 등쪽솔기핵내 도파민성 신경세포와 별아교세포에 미치는 영향

홍은석(Eun Seog Hong),남성안(Seong Ahn Nam),조승묵(Seung Mook Jo),강태천(Tae-Cheon Kang),원무호(Moo Ho Won),최창도(Chang Do Choi) 대한해부학회 1999 Anatomy & Cell Biology Vol.32 No.4

신경독성물질인 6-hydroxydopamine (6-OHDA)이 중추신경계통 내 도파민성 신경세포에 미치는 영향과 이에 따른 별아교 세포들의 반응을 형태학적으로 규명하고자 본 연구를 시행하였다. 흰쥐의 가쪽뇌실에 6-OHDA를 투여한 후 면역조직화학 염색을 시행하여 광학현미경 하에서 등쪽솔기핵 내 도파민성 신경세포에 나타나는 퇴행성변화와 주위 별아교세포들의 반응양상 등을 경시적으로 제 3일, 제 5일, 제10일 및 제20일에서 관찰하였던 바 아래와 같은 결과를 얻었다. 6-OHDA에 의한 도파민성 신경세포의 퇴행성변화는 약물투여후 제 3일군에서 세포돌기가 팽대되고, 제 5일군과 제 10일군에서는 세포돌기의 소실과 함께 세포체가 위축되었고, 제20일군에서는 세포체가 소실되었다. 또한 6-OHDA에 의해 도파민성 신경세포들의 손상이 진행되면서 별아교세포들의 반응양상은 제 5일에서 대조군에 비해 급격하게 증가하였으며, 제20일에 이르러 최고값을 보였다. 이상의 결과로부터 6-OHDA가 중추신경계통 내 도파민성 신경세포들에 선택적이고 강한 세포독성을 유발하여 퇴행성 변화가 진행되고, 세포 손상이 시간 경과에 따라 진행되면서 주위의 별아교세포들이 지속적으로 증가된 활동을 보인다는 사실을 알게 되었다. This study was designed to clarify the cytotoxic effects of 6-hydroxydopamine (6-OHDA) on the dopaminergic neurons and astrocytes in the dorsal raphe nucleus (DRN), and to investigate neurodegenerative changes by immunohistochemistry. Adult male rats (Sprague-Dawley strain) weighing from 250 to 350 g were used as experimental animals. 6-OHDA (100 μg dissolved in 0.1% ascorbic acid) was injected into the lateral ventricle of the rat brain with the Hamilton syringe. The control rats were treated with the similar volume of 0.1 % ascorbic acid. The rats were sacrificed at the 3rd, 5th, 10th and 20th day, respectively, after the injection of 6-OHDA. The cytotoxicity of 6-OHDA resulted in severe neurodegeneration of the dopaminergic neurons in the DRN. In the 3rd day, the dopaminergic fibers were dilated. In the 5th and 10th days, the dopaminergic fibers were depleted, and dopaminergic cell bodies were shrunken. In the 20th day, the dopaminergic cell bodies were almost completely disappeared. Astroglial reactions induced by 6-OHDA were also observed in the DRN. In the 5th day, astrocytes were significantly increased as compared with that of the control value. The value were reached at its maximum by the 20th day. Based on the present results, it suggests that 6-OHDA may act as a specific neurotoxin to dopaminergic neurons in the DRN, and induce severe neurodegenerative changes. Also, it suggests that the astroglial reaction in the DRN is gradually activated during the neurodegerative changes

Surface Morphology Control of Polymer Films by Electron Irradiation and Its Application to Superhydrophobic Surfaces

Lee, Eun Je,Jung, Chan-Hee,Hwang, In-Tae,Choi, Jae-Hak,Cho, Sung Oh,Nho, Young-Chang American Chemical Society 2011 ACS APPLIED MATERIALS & INTERFACES Vol.3 No.8

<P>A simple and controllable one-step method to fabricate superhydrophobic surfaces on poly(tetrafluoroethylene) (PTFE) films is developed on the base of electron irradiation. When the thickness of PTFE films is higher than the penetration depth of electron beams, electrical charging occurs at the surface of the films because of the imbalance between the accumulation of incident electrons and the emission of secondary electrons. Local inhomogeneity of charge distribution due to this electrical charging results in the nonuniform decomposition of PTFE molecular bonds. As electron fluence increases, surface morphology and surface roughness of the films are dramatically changed. An extremely rough surface with micrometer-sized pores is produced on the surface of PTFE films by electron irradiation at a fluence higher than 2.5 × 10<SUP>17</SUP> cm<SUP>–2</SUP>.Because of high surface roughness, the irradiated PTFE films exhibit superhydrophobic property with a water contact angle (CA) greater than 150° at fluences ranging from 4 × 10<SUP>17</SUP> to 1 × 10<SUP>18</SUP> cm<SUP>–2</SUP>. The surface morphology and corresponding water CA can be controlled by simply changing the electron fluence. This electron irradiation method can be applicable to the fabrication of superhydrophobic surfaces using other low-surface-energy materials including various fluoropolymers.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2011/aamick.2011.3.issue-8/am200464a/production/images/medium/am-2011-00464a_0004.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am200464a'>ACS Electronic Supporting Info</A></P>

Effect of 2-Deoxy-D-Glucose on Metabolic Status, Proliferative Capacity and Growth Rate of FSall Tumor

Hyesook Chang(장혜숙) , Eun Kyung Choi최은경) , Jeong Gill Cho(조정길) , Tae-Hwan Lim(임태환) , Tae-Keun Lee(이대근) ,Yun Yi(이윤) ,Young Joo Cho(조영주) , Gon Sup Kim(김곤섭) 대한방사선종양학회 1991 Radiation Oncology Journal Vol.9 No.1

2-DDG가 쥐의 섬유육종(FSall)에 미치는 영향에 대한 연구로 에너지 신진대사는 체내에서의 ³¹P - 자기공명 분광기를 이용하여 관찰하였고 세포 증식 능력은 유세포 분석기를 사용하여 연구하였다. 성장속도는 개의 세포를 C₃Hj/Sed 쥐의 발등에 이식한 후 3차원적으로 측정하여 관찰하였다. 2-DDG를 투여한 경우에는 이식후 12일에 복강내로 주사하였다. 이식후 12일의 종양의 평균 크기는 250㎣이었다. FSall 종양의 성장속도는 semilog graph의 기울기와 종양의 doubling time으로 측정하였다. 2-DDG를 투여한 후 성장속도가 감속되었다. 5~12일 사이의 성장속도의 기울기가 0.828, 종양의 Idubling time이 0.84일이고 대조군에서는 13~28일 사이의 기울기가 0.218, doubling time이 3.2일인 반면 2-DDG 투여군에서는 성장속도의 기울기가 0.135이고 doubling time이 5.1일이었다. ³¹P-자기공명 분광기를 이용하여 2-DDG의 영향을 분석해 본 결과 2-DDG 투여후 종양증식 속도의 감속과 더불어 phosphomonester (PME)와 inorganic phosphate (Pi)의 증가속도가 감소하였다. 이것은 2-DDG 투여후 세포의 괴사가 감소하였다는 의미가 있다. 유세포 분석기를 이용하여 종양의 증식 능력을 분석한 결과는 2-DDG 투여후 S-phase와 G₂+M phase의 DNA 분포가 크게 증가하였다. 이것은 2-DDG 투여후 세포가 좀더 방사선에 민감한 cycle로 진행함을 의미하는 것으로 해석할 수 있다. 이에 저자들은 2-DDG가 FSall 종양세포에 미치는 흥미있는 결과를 토대로 방사선 치료에 미치는 영향과 실제 이용 가능성에 대하여 더 연구하고자 한다. The effect of 2-deoxy-d-glucose (2-DDG) on C₃H mouse fibrosarcoma(FSall) was studied, Metabolic status, especially for energy metabolism, was studied using in vivo P-MRS, prolifer-ative capacity was observed on flow cytometry(FC) and growth rate was measured after trans-plantation of viable tumor cells in the dorsum of foot of C₃Hf/Sed mice. One gram of 2-DDG per kg of body weight was injected intraperitoneally on 12th day of implantation. Average tumor size on 12th day of implantion was 250㎣. Growth rate of FSall tumor was measured by tumor doubling time and slope on semilog plot. After 2-DDG injection, growth rate slowed down. Tumor doubling time between tumor age 5-12 days was 3.2 days with slope 0.218 in control group. After 2-DDG injection, tumor doubling time was elongated to 5.1 days with slope 0.136. The effect of 2-DDG studied in vivo P-MRS suggested that the increase of phosphomonoes-ter (PME) and inorganic phosphate (Pi) by increasing size of tumor, slowed down after 2-DDG injection. Flow cytometry showed significantly increased S-phase and G₂ + M phase fraction suggesting increased proliferative capacity of tumor cells in the presence of 2-DDG. Authors observed an interesting effect of 2-DDG on FSall tumor and attempt to utilize as an adjunct for radiotherapy.

Altered Regulation of Renal Acid Base Transporters in Response to Ammonium Chloride Loading in Rats

Kim, Eun-Young,Choi, Joon-Seok,Lee, Ko-Eun,Kim, Chang-Seong,Bae, Eun-Hui,Ma, Seong-Kwon,Kim, Suhn-Hee,Lee, Jong-Un,Kim, Soo-Wan The Korean Society of Pharmacology 2012 The Korean Journal of Physiology & Pharmacology Vol.16 No.2

The role of the kidney in combating metabolic acidosis has been a subject of considerable interest for many years. The present study was aimed to determine whether there is an altered regulation of renal acid base transporters in acute and chronic acid loading. Male Sprague-Dawley rats were used. Metabolic acidosis was induced by administration of $NH_4Cl$ for 2 days (acute) and for 7days (chronic). The serum and urinary pH and bicarbonate were measured. The protein expression of renal acid base transporters [type 3 $Na^+/H^+$ exchanger (NHE3), type 1 $Na^+/{HCO_3}^-$ cotransporter (NBC1), Na-$K^+$ ATPase, $H^+$-ATPase, anion exchanger-1 (AE-1)] was measured by semiquantitative immunoblotting. Serum bicarbonate and pH were decreased in acute acid loading rats compared with controls. Accordingly, urinary pH decreased. The protein expression of NHE3, $H^+$-ATPase, AE-1 and NBC1 was not changed. In chronic acid loading rats, serum bicarbonate and pH were not changed, while urinary pH was decreased compared with controls. The protein expression of NHE3, $H^+$-ATPase was increased in the renal cortex of chronic acid loading rats. These results suggest that unaltered expression of acid transporters combined with acute acid loading may contribute to the development of acidosis. The subsequent increased expression of NHE3, $H^+$-ATPase in the kidney may play a role in promoting acid excretion in the later stage of acid loading, which counteract the development of metabolic acidosis.

Analysis of Research Trends in Nitrous Oxide Emissions from Upland in Korea

Sun-Il Lee,Chang-Kyu Lee,Gun-Yeob Kim,Hyo-Suk Gwon,Jong-Sik Lee,Eun-Jung Choi,Joung-Du Shin 한국토양비료학회 2019 한국토양비료학회지 Vol.52 No.4

Global climate change, especially global warming is considered as threat to our future and posterity. Increasing concentrations of greenhouse gas such as carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O) are the main causes of global warming. The Korean government has set a goal to cut the carbon emissions by 37% based on business-as-usual levels by 2030. According to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), agricultural sector is an important source of greenhouse gas emissions. In this regard, it is common belief that reducing of such emission is of great significance to global climate change. In Korea, upland is one of the main sources of agricultural N₂O emission. In order to analyze domestic research trends related to N₂O emissions in the upland, 53 academic publications from 2009 to September 2019 were critically reviewed. The results were classified according to the research purposes. Reduction technologies of N₂O emission account for approximately 28.3%. N₂O characteristics and assessment for 24.5%, development of N₂O emission factors for 22.6%, and N₂O inventory assessment for 20.8% etc. Biochar, green manure, no tillage, and inhibitor were studied as a means of reducing N₂O release. The optimum technologies to reduce N₂O emission in Korea were discussed and proposed through the previous researches.