کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2840630 1165341 2012 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Recent experiments towards a model for fluid secretion in Rhodnius Upper Malpighian Tubules (UMT)
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک دانش حشره شناسی
پیش نمایش صفحه اول مقاله
Recent experiments towards a model for fluid secretion in Rhodnius Upper Malpighian Tubules (UMT)
چکیده انگلیسی

Three different methods have been used to improve a model for fluid secretion in Upper Malpighian Tubules (UMT) of the blood sucking insect Rhodnius prolixus. (I) In the first, UMT double perfusions in 5th instar Rhodnius were used to measure their fluid secretion rate. They were stimulated to secrete with 5-HT. Double perfusions allowed access separately to the basolateral and the apical cell membranes with pharmacological agents known to block different ion transport functions, namely ATPases, cotransporters and/or countertransporters and ion and water channels: ouabain, bafilomycin A1, furosemide, bumetanide, SITS, acetazolamide, amiloride, DPC, BaCl2, pCMBS and DTT. The basic assumption is that changes in water movement reflect changes in ion transport mechanisms. (II) Intracellular Na+ concentrations were measured with a fluorometric method in dissected R. prolixus UMT, under several experimental conditions. (III) ATPase activities were measured in R. prolixus UMT. A tentative model for the function of the UMT cell is presented. We find that (a) at the basolateral cell membrane, fundamental is a Na+–K+–2Cl− cotransporter; of intermediate importance are the Na+–K+-ATPase and a ouabain-insensitive Na+-ATPase, ion channels and Rp-MIP water channels. (b) At the apical cell membrane, most important are a V-H+-ATPase; and a K+ and/or Na+–H+ exchanger.

Figure optionsDownload as PowerPoint slideHighlights
► Rhodnius malpighian tubule secretion, [Na+]i, and ATPase activity were assayed.
► The effects of different transporter and channel blockers were tested.
► At the basolateral membrane, a Na+–K+–2Cl− cotransporter is fundamental.
► A V-H+-ATPase and a K+/Na+–H+ exchanger are most important at the apical membrane.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Insect Physiology - Volume 58, Issue 4, April 2012, Pages 543–550
نویسندگان
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