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Real-time Imaging of Ca-handling in Intact Renal Glomeruli Using Confocal Microscopy. 用共聚焦显微镜观察完整肾小球钙处理的实时成像。

Medical hypotheses and research : MHR Pub Date : 2009-07-01

Muhammad Nabeel Ghayur, Luke Jeffrey Janssen

{"title":"Real-time Imaging of Ca-handling in Intact Renal Glomeruli Using Confocal Microscopy.","authors":"Muhammad Nabeel Ghayur, Luke Jeffrey Janssen","doi":"","DOIUrl":"","url":null,"abstract":"Glomeruli are filtering units in the kidneys. Being multicellular and complex in structure, many aspects of glomerular function are yet to be elucidated. Most studies use glomerular cells in culture, which may exhibit altered physiology compared to native cells. Confocal microscopy has opened new avenues in exploring in situ glomerular function and physiology. In this report, we propose experimenting with glomerular cells in renal cortical slices and isolated intact glomeruli for Ca(2+)-handling studies. Cortical slices (100 μm thick) were obtained from mice while intact glomeruli were isolated from rats using the sieving method. These were loaded with fluo-4 and then placed in a confocal microscope. Fluo-4 was excited using a 488 nm photodiode laser and images were collected at 1 frame/sec. Changes in average fluorescence intensity (AFI) were interpreted as changes in [Ca(2+)](i). AFI increased to 37.1 ± 6.7% and 84.3 ± 20.9% with Ang II (0.01 and 0.1 μM respectively). Norepinephrine (10 μM), arginine vasopressin (0.1 μM) and K(+) (30 mM) also elevated AFI by 26.5 ± 6.8%, 22.3 ± 1.0% and 39.8 ± 10.3% respectively in the glomerular cells. Likewise in isolated glomeruli, Ang II (0.1-10 μM), K(+) (30-90 mM) and endothelin-1 (0.01-1 μM), all showed elevation in [Ca(2+)](i). These results give an impetus for future studies examining Ca(2+)-handling by confocal microscopy in glomerular cells using renal cortical slices and isolated intact glomeruli. The results support the utility of this system for study of glomerular physiology and pharmacology.","PeriodicalId":89600,"journal":{"name":"Medical hypotheses and research : MHR","volume":"5 1/2","pages":"47-56"},"PeriodicalIF":0.0,"publicationDate":"2009-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3266942/pdf/nihms2041.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30421551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

CONTRACTILITY OF THE RENAL GLOMERULUS AND MESANGIAL CELLS: LINGERING DOUBTS AND STRATEGIES FOR THE FUTURE. 肾小球和系膜细胞的收缩性：挥之不去的疑问和未来的策略。

Medical hypotheses and research : MHR Pub Date : 2008-01-01

Muhammad N Ghayur, Joan C Krepinsky, Luke J Janssen

{"title":"CONTRACTILITY OF THE RENAL GLOMERULUS AND MESANGIAL CELLS: LINGERING DOUBTS AND STRATEGIES FOR THE FUTURE.","authors":"Muhammad N Ghayur, Joan C Krepinsky, Luke J Janssen","doi":"","DOIUrl":"","url":null,"abstract":"Kidneys can be divided into four components: glomeruli, tubules, interstitium and blood vessels. The renal glomerulus consists of a network of capillaries covered with epithelial cells called podocytes. The entire glomerular tuft is structurally supported by mesangial cells which are contractile in nature and resemble vascular smooth muscle cells. Mesangial cells are secretory, producing growth factors and matrix proteins which have a role in both normal glomerular development and in pathologic states. They have also been shown to take the role of macrophages. The importance of mesangial cell contraction to glomerular physiology remains debated. It is postulated that mesangial cell contraction can attenuate the glomerular filtration rate by decreasing the renal ultrafiltration coefficient through a decrease in capillary surface area and capillary permeability. The physiology of mesangial cell contraction has been studied primarily utilizing cultured cells. The physiological status of receptors and ion channels may be doubtful, however, given the phenotypic changes cells are known to acquire in culture conditions. The contractility of renal glomeruli has been less well studied. In this report, we review the available data regarding the contractility of mesangial cell and of renal glomeruli. Moreover, we suggest newer techniques that can be used with whole glomeruli, thereby improving upon the data collected using previous techniques and cultured cells.","PeriodicalId":89600,"journal":{"name":"Medical hypotheses and research : MHR","volume":"4 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3266944/pdf/nihms2040.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30421550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0