Characterization of Whole Cell Chloride Conductances in a Mouse Inner Medullary Collecting Duct Cell Line mIMCD-3

1996 ◽  
Vol 149 (1) ◽  
pp. 21-31 ◽  
Author(s):  
M. Shindo ◽  
N.L. Simmons ◽  
M.A. Gray
Keyword(s):  
Cell Line ◽  
Collecting Duct ◽  
Duct Cell ◽  
Whole Cell ◽  
Inner Medullary Collecting Duct ◽  
Medullary Collecting Duct

Early transcriptional effects of aldosterone in a mouse inner medullary collecting duct cell line

2003 ◽  
Vol 285 (4) ◽  
pp. F664-F673 ◽  
Author(s):  
Michelle L. Gumz ◽  
Michael P. Popp ◽  
Charles S. Wingo ◽  
Brian D. Cain
Keyword(s):  
Cell Line ◽  
Cellular Response ◽  
Collecting Duct ◽  
Duct Cell ◽  
Immunoblot Analysis ◽  
Tissue Growth ◽  
Long Term Effects ◽  
Acid Base Balance ◽  
Inner Medullary Collecting Duct ◽  
Medullary Collecting Duct

The mineralocorticoid aldosterone is a major regulator of Na+ and acid-base balance and control of blood pressure. Although the long-term effects of aldosterone have been extensively studied, the early aldosterone-responsive genes remain largely unknown. Using DNA array technology, we have characterized changes in gene expression after 1 h of exposure to aldosterone in a mouse inner medullary collecting duct cell line, mIMCD-3. Results from three independent microarray experiments revealed that the expression of many transcripts was affected by aldosterone treatment. Northern blot analysis confirmed the upregulation of four distinct transcripts identified by the microarray analysis, namely, the serum and glucose-regulated kinase sgk, connective tissue growth factor, period homolog, and preproendothelin. Immunoblot analysis for preproendothelin demonstrated increased protein expression. Following the levels of the four transcripts over time showed that each had a unique pattern of expression, suggesting that the cellular response to aldosterone is complex. The results presented here represent a novel list of early aldosterone-responsive transcripts and provide new avenues for elucidating the mechanism of acute aldosterone action in the kidney.

H+ secretion is inhibited by clostridial toxins in an inner medullary collecting duct cell line

1997 ◽  
Vol 273 (6) ◽  
pp. F1054-F1057 ◽  
Author(s):  
Edward A. Alexander ◽  
Theodora Shih ◽  
John H. Schwartz
Keyword(s):  
Epithelial Cell ◽  
Cell Line ◽  
Collecting Duct ◽  
Duct Cell ◽  
Specific Protein ◽  
Proton Pumps ◽  
Renal Epithelial Cell ◽  
Inner Medullary Collecting Duct ◽  
Medullary Collecting Duct ◽  
Cell Acid

Renal epithelial cell H+secretion is an exocytic-endocytic phenomenon. In the inner medullary collecting duct (IMCD) cell line, which we have utilized as a model of renal epithelial cell acid secretion, we found previously that acidification increased exocytosis and alkalinization increased endocytosis. It is likely, therefore, that the rate of proton secretion is regulated by the membrane insertion and retrieval of proton pumps. There is abundant evidence from studies in the nerve terminal and the chromaffin cell that vesicle docking, membrane fusion, and discharge of vesicular contents (exocytosis) involve a series of interactions among so-called trafficking proteins. The clostridial toxins, botulinum and tetanus, are proteases that specifically inactivate some of these proteins. In these experiments we demonstrated, by immunoblot and immunoprecipitation, the presence in this IMCD cell line of the specific protein targets of these toxins, synaptobrevin/vesicle-associated membrane proteins (VAMP), syntaxin, and synaptosomal-associated protein-25 (SNAP-25). Furthermore, we showed that these toxins markedly inhibit the capacity of these cells to realkalinize after an acid load. Thus these data provide new insight into the mechanism for H+ secretion in the IMCD.

scholarly journals microRNA Regulation of endothelin-1 in an inner medullary collecting duct cell line

Life Sciences ◽  
2013 ◽  
Vol 93 (25-26) ◽  
pp. e37
Author(s):  
Mollie E./INS; Jacobs ◽  
Lauren A./INS; Jeffers ◽  
Amanda K./INS; Welch ◽  
Charles S./INS; Wingo ◽  
Brian D./INS; Cain
Keyword(s):  
Cell Line ◽  
Collecting Duct ◽  
Duct Cell ◽  
Microrna Regulation ◽  
Endothelin 1 ◽  
Inner Medullary Collecting Duct ◽  
Medullary Collecting Duct

scholarly journals Characterization of anion exchangers in an inner medullary collecting duct cell line.

1998 ◽  
Vol 9 (5) ◽  
pp. 746-754
Author(s):  
G Obrador ◽  
H Yuan ◽  
T M Shih ◽  
Y H Wang ◽  
M A Shia ◽  
...  
Keyword(s):  
Cell Line ◽  
Anion Exchanger ◽  
Collecting Duct ◽  
Basolateral Membrane ◽  
Disulfonic Acid ◽  
Kidney Cortex ◽  
Intercalated Cells ◽  
Rat Stomach ◽  
Inner Medullary Collecting Duct ◽  
Medullary Collecting Duct

Although the inner medullary collecting duct (IMCD) plays a major role in urinary acidification, the molecular identification of many of the specific components of the transport system in this nephron segment are lacking. A cultured line of rat IMCD cells was used to characterize the mediators of cellular HCO3 exit. This cell line functionally resembles alpha-intercalated cells. Physiologic experiments document that HCO3- transport is a reversible, electroneutral, Cl dependent, Na+-independent process. It can be driven by Cl-gradients and inhibited by stilbenes such as 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid. Immunohistochemical analysis, using a rabbit polyclonal antibody against the carboxy-terminal 12 amino acids of anion exchanger 1 (AE1), revealed a distribution of immunoreactive protein that is consistent with a basolateral localization of AE in cultured cells and in alpha-intercalated cells identified in sections of rat kidney cortex. Immunoblot revealed two immunoreactive bands (approximately 100 and 180 kD in size) in membranes from cultured IMCD cells, rat renal medulla, and freshly isolated IMCD cells. The mobility of the lower molecular weight band was similar to that of AE1 in red blood cell ghosts and kidney homogenate and therefore probably represents AE1. The mobility of the 180-kD band is similar to that for rat stomach and kidney AE2 and therefore probably represents AE2. Selective biotinylation of the apical or basolateral membrane proteins in cultured IMCD cells revealed that both AE1 and AE2 are polarized to the basolateral membrane. Northern blot analysis documented the expression of mRNA for AE1 and AE2 but not AE3. Furthermore, the cDNA sequence of AE1 and AE2 expressed by these cells was found to be virtually identical to that reported for kidney AE1 and rat stomach AE2. It is concluded that this cultured line of rat IMCD cells expresses two members of the anion exchanger gene family, AE1 and AE2, and both of these exchangers probably mediate the electroneutral Cl--dependent HCO3-transport observed in this cell line.

Characterization of the urea transporter in outer medullary descending vasa recta

1994 ◽  
Vol 267 (1) ◽  
pp. R260-R267 ◽  
Author(s):  
T. L. Pallone
Keyword(s):  
Collecting Duct ◽  
Urea Transporter ◽  
Maximal Inhibition ◽  
Sodium Permeability ◽  
Inner Medullary Collecting Duct ◽  
Vasa Recta ◽  
Order Of Magnitude ◽  
Thiourea Concentration ◽  
Medullary Collecting Duct

Partially because of facilitated transport of urea, urea permeability (Pu) of the outer medullary descending vasa recta (OMDVR) frequently exceeds sodium permeability by more than an order of magnitude. This study characterizes the OMDVR urea transporter. Application of the urea analogue thiourea (200 mM) to the abluminal surface of microperfused OMDVR inhibited Pu by 33%. When osmolarity due to thiourea was balanced by addition of mannitol or thiourea, similar results were obtained. Thiourea produced graded inhibition of Pu from 343 +/- 54 (SE) to 191 +/- 43 x 10(-5) cm/s as concentration was increased from 0 to 100 mM. The thiourea concentration needed for half-maximal inhibition was 19 mM. The abilities of urea analogues to reduce Pu were compared by addition of 50 mM concentrations to the bath and perfusate. Thiourea and methylurea produced 32 and 34% inhibition of Pu, respectively, whereas urea and acetamide produced only 3 and 11% inhibition, respectively. The transporter showed negligible saturation as the transmural urea gradient was increased from 0 to 200 mM. Phloretin and p-chloromercuribenzenesulfonate inhibited Pu in a concentration-dependent fashion. It is concluded that a transporter confers high Pu to OMDVR. Pu is equally high when measured by urea influx or efflux. Properties of the transporter are similar to those expressed by the inner medullary collecting duct.

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