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Full-Text Articles in Medicine and Health Sciences
On The Mechanism Of Parathyroid Hormone Stimulation Of Calcium Uptake By Mouse Distal Convoluted Tubule Cells, F A. Gesek, A. Friedman
On The Mechanism Of Parathyroid Hormone Stimulation Of Calcium Uptake By Mouse Distal Convoluted Tubule Cells, F A. Gesek, A. Friedman
Dartmouth Scholarship
PTH stimulates transcellular Ca2+ absorption in renal distal convoluted tubules. The effect of PTH on membrane voltage, the ionic basis of the change in voltage, and the relations between voltage and calcium entry were determined on immortalized mouse distal convoluted tubule cells. PTH (10(-8) M) significantly increased 45Ca2+ uptake from basal levels of 2.81 +/- 0.16 to 3.88 +/- 0.19 nmol min-1 mg protein-1. PTH-induced 45Ca2+ uptake was abolished by the dihydropyridine antagonist, nifedipine (10(-5) M). PTH did not affect 22Na+ uptake. Intracellular calcium activity ([Ca2+]i) was measured in cells loaded with fura-2. Control [Ca2+]i averaged 112 +/- 21 nM. …
Mechanism Of Calcium Transport Stimulated By Chlorothiazide In Mouse Distal Convoluted Tubule Cells., Frank A. Gesek, Peter A. Friedman
Mechanism Of Calcium Transport Stimulated By Chlorothiazide In Mouse Distal Convoluted Tubule Cells., Frank A. Gesek, Peter A. Friedman
Dartmouth Scholarship
Thiazide diuretics inhibit Na+ and stimulate Ca2+ absorption in renal distal convoluted tubules. Experiments were performed on immortalized mouse distal convoluted tubule (MDCT) cells to determine the mechanism underlying the dissociation of sodium from calcium transport and the stimulation of calcium absorption induced by thiazide diuretics. Control rates of 22Na+ uptake averaged 272 +/- 35 nmol min-1 mg protein-1 and were inhibited 40% by chlorothiazide (CTZ, 10(-4) M). Control rates of 36Cl- uptake averaged 340 +/- 50 nmol min-1 mg protein-1 and were inhibited 50% by CTZ. CTZ stimulated 45Ca2+ uptake by 45% from resting levels of 2.86 +/- 0.26 …
Differential Regulation Of Collagenase Gene Expression By Retinoic Acid Receptors--Alpha, Beta And Gamma, Luying Pan, Stephen H. Chamberlain, David T. Auble, Constance E. Brinckerhoff
Differential Regulation Of Collagenase Gene Expression By Retinoic Acid Receptors--Alpha, Beta And Gamma, Luying Pan, Stephen H. Chamberlain, David T. Auble, Constance E. Brinckerhoff
Dartmouth Scholarship
The mechanisms involved in retinoic acid (RA)-mediated regulation of the collagenase gene in a rabbit synovial fibroblast cell line (HIG82) were investigated. When HIG82 cells are cotransfected with expression vectors containing cDNAs for retinoic acid receptor (RAR) α1, β2, or γ1 and collagenase promoter-driven CAT reporter constructs, only RAR-γ1 represses basal CAT expression upon RA treatment, while RAR-α1, β2, and γ1 all suppress phorbol-induced CAT expression. Thus, transcriptional regulation of collagenase by RA is mediated by RARs in an RAR-type specific manner. Using mutatlonal and deletional analysis, we find that interaction between elements within 182 bp collagenase promoter plays an …
Differentiation Of Renal Beta-Intercalated Cells To Alpha-Intercalated And Principal Cells In Culture., Geza Fejes-Tóth, Aniko Náray-Fejes-Tóth
Differentiation Of Renal Beta-Intercalated Cells To Alpha-Intercalated And Principal Cells In Culture., Geza Fejes-Tóth, Aniko Náray-Fejes-Tóth
Dartmouth Scholarship
The renal collecting duct is a heterogenous epithelium consisting of intercalated cells (ICC) and principal cells (PC). The origin of this cellular heterogeneity is not clear. To test the hypothesis that the two cell types might originate from one another, pure populations of ICC (beta subtype) and PC were isolated by fluorescence-activated cell sorting and grown on permeable supports. After the monolayers reached confluence, the expression of ICC- and PC-specific functions and antigens was monitored. Cultures of sorted beta-ICC, in addition to expressing ICC-specific functions (such as an electrogenic H+ secretion) and antigens, progressively acquired PC functions (amiloride-sensitive Na+ transport …
Cytolytic T Lymphocytes Specific For Tumors And Infected Cells From Mice With A Retrovirus-Induced Immunodeficiency Syndrome., Jennifer G. Erbe, Kathy A. Green, Karen M. Crassi, Herbert C. Morse, W R. Green
Cytolytic T Lymphocytes Specific For Tumors And Infected Cells From Mice With A Retrovirus-Induced Immunodeficiency Syndrome., Jennifer G. Erbe, Kathy A. Green, Karen M. Crassi, Herbert C. Morse, W R. Green
Dartmouth Scholarship
LP-BM5 retrovirus complex-infected C57BL/6 mice develop immunodeficiency, somewhat analogous to AIDS, termed murine AIDS (MAIDS). After secondary stimulation with syngeneic B-cell lymphomas from LP-BM5-infected mice, C57BL/6 mice produced vigorous CD8+ cytotoxic T lymphocytes specific for MAIDS-associated tumors. An anti-LP-BM5 specificity was suggested because spleen and lymph node cells from LP-BM5-infected mice served as target cells in competition assays, and cells from LP-BM5, but not ecotropic, virus-infected mice functioned as secondary in vitro stimulators to generate cytotoxic T lymphocytes to MAIDS tumors.
Transformation Of A Continuous Rat Embryo Fibroblast Cell Line Requires Three Separate Domains Of Simian Virus 40 Large T Antigen., Jiyue Zhu, Philip W. Rice, Lisa Gorsch, Marina Abate, Charles N. Cole
Transformation Of A Continuous Rat Embryo Fibroblast Cell Line Requires Three Separate Domains Of Simian Virus 40 Large T Antigen., Jiyue Zhu, Philip W. Rice, Lisa Gorsch, Marina Abate, Charles N. Cole
Dartmouth Scholarship
Mouse C3H 10T1/2 cells and the established rat embryo fibroblast cell line REF-52 are two cell lines widely used in studies of viral transformation. Studies have shown that transformation of 10T1/2 cells requires only the amino-terminal 121 amino acids of simian virus 40 (SV40) large T antigen, while transformation of REF-52 cells requires considerably more of large T antigen, extending from near the N terminus to beyond residue 600. The ability of a large set of linker insertion, small deletion, and point mutants of SV40 T antigen to transform these two cell lines and to bind p105Rb was determined. Transformation …
Adenosine Regulates A Chloride Channel Via Protein Kinase C And A G Protein In A Rabbit Cortical Collecting Duct Cell Line., Erik M. Schwiebert, Katherine H. Karlson, Peter A. Friedman, Paul Dietl, William S. Spielman, Bruce Stanton
Adenosine Regulates A Chloride Channel Via Protein Kinase C And A G Protein In A Rabbit Cortical Collecting Duct Cell Line., Erik M. Schwiebert, Katherine H. Karlson, Peter A. Friedman, Paul Dietl, William S. Spielman, Bruce Stanton
Dartmouth Scholarship
We examined the regulation by adenosine of a 305-pS chloride (Cl-) channel in the apical membrane of a continuous cell line derived from rabbit cortical collecting duct (RCCT-28A) using the patch clamp technique. Stimulation of A1 adenosine receptors by N6-cyclohexyladenosine (CHA) activated the channel in cell-attached patches. Phorbol 12,13-didecanoate and 1-oleoyl 2-acetylglycerol, activators of protein kinase C (PKC), mimicked the effect of CHA, whereas the PKC inhibitor H7 blocked the action of CHA. Stimulation of A1 adenosine receptors also increased the production of diacylglycerol, an activator of PKC. Exogenous PKC added to the cytoplasmic face of inside-out patches also stimulated …