Transport of Cimetidine across the Basolateral Membrane of Rabbit Kidney Proximal Tubules: Interaction with Organic Anions

Pharmacology ◽  
1992 ◽  
Vol 45 (4) ◽  
pp. 231-240 ◽  
Author(s):  
E. Brändle ◽  
J. Greven
Keyword(s):  
Basolateral Membrane ◽  
Organic Anions ◽  
Proximal Tubules ◽  
Rabbit Kidney ◽  
Kidney Proximal Tubules

Basis for heterogeneity of para-aminohippurate secretion in rabbit proximal tubules

1981 ◽  
Vol 240 (5) ◽  
pp. F430-F436 ◽  
Author(s):  
A. Shimomura ◽  
A. M. Chonko ◽  
J. J. Grantham
Keyword(s):  
Basolateral Membrane ◽  
Proximal Tubules ◽  
Rabbit Kidney ◽  
Passive Component ◽  
Maximal Rate ◽  
Michaelis Constant ◽  
Slope Analysis ◽  
High Concentrations ◽  
The Relationship ◽  
Membrane Density

Para-aminohippurate (PAH) is secreted at different rates in S1, S2, and S3 segments of isolated perfused proximal tubules of rabbit kidney. To characterize PAH transport we determined the maximal rate of secretion (Vmax) and the apparent Michaelis constant (Km) for each segment by examining the relationship between bath concentration of PAH and net PAH secretion (Jb leads to lPAH) transposed for Lineweaver-Burk analysis. The passive component of secretion for all segments was estimated by slope analysis at relatively high concentrations of PAH, by the component of PAH secretion insensitive to inhibition by probenecid, and, additionally, in S2 segments, from PAH efflux from lumen to bath. Subtraction of the passive component from Jb leads to lPAH (probenecid method) gave Vmax values for S1, S2, and S3 segments of 1,097 +/- 336 (n = 6), 7,430 +/- 1,338 (n = 6), 1,647 +/+ 138 (n = 8) X 10(-15) mol.min-1.mm-1 (+/- SE) and apparent Km values of 139 +/– 37 (n = 6), 195 +/- 37 (n = 6), and 113 +/- 16 (n = 6) X 10(-6) M, respectively. Thus, Vmax for S2 greater than S3 congruent to S1, whereas apparent Km was not consistently different among the segments. On the basis of these results we suggest that axial heterogeneity of PAH secretion may reflect an increased basolateral membrane density of PAH transporters of common affinity in the S2 segment of the proximal tubule.

Intracellular potentials in rabbit proximal tubules perfused in vitro

1981 ◽  
Vol 240 (3) ◽  
pp. F200-F210 ◽  
Author(s):  
B. Biagi ◽  
T. Kubota ◽  
M. Sohtell ◽  
G. Giebisch
Keyword(s):  
Membrane Potential ◽  
Basolateral Membrane ◽  
Proximal Tubules ◽  
Rabbit Kidney ◽  
Electrical Measurements ◽  
Proximal Tubular ◽  
The Mean ◽  
Number Of Cells ◽  
Basolateral Membrane Potential

Conventional microelectrodes were used to measure the basolateral membrane potential (VBL) in isolated perfused superficial proximal convoluted (sPCT) and superficial proximal straight (sPST) tubules of the rabbit kidney. Stable recordings for periods up to 2 h can be obtained. The mean +/- SE (n = number of cells) values of VBL were sPCT = -51.0 +/- 1.63 (24) and sPST = -47.0 +/- 0.97 (94) mV. Inhibitors of active transport, ouabain (10(-5) M) and low bath potassium (0.1 mM), caused a significant depolarization of VBL in sPST. In contrast, short-duration bath cooling (10 degrees C) had no significant effect. Removal of luminal glucose caused a larger hyperpolarization in sPCT (-13.9 +/- 1.77 (9) mV) than in sPST (-3.8 +/- 1.02 (5) mV). Removal of luminal glucose and alanine resulted in an even larger hyperpolarization of VBL in sPCT (-19.0 +/- 0.44 (6) mV). Perfusion of the lumen with a solution resembling late proximal tubular fluid in sPST resulted in hyperpolarization of VBL (-4.3 +/- 0.85 (4) mV). Reducing bath pH to 6.7 depolarized VBL (39.9 +/- 1.77 (13) mV). This effect can be associated with a decrease in the relative potassium permeability of the basolateral membrane. These results demonstrate the feasibility of using intracellular electrical measurements to determine both luminal and basolateral membrane characteristics in isolated proximal tubular segments.

Localization of NaPi-1, a Na-Pi cotransporter, in rabbit kidney proximal tubules

1993 ◽  
Vol 424 (3-4) ◽  
pp. 203-209 ◽  
Author(s):  
Maria Custer ◽  
Felix Meier ◽  
Eberhard Schlatter ◽  
Rainer Greger ◽  
Arlyn Garcia-Perez ◽  
...  
Keyword(s):  
Proximal Tubules ◽  
Rabbit Kidney ◽  
Kidney Proximal Tubules

Localization of NaPi-1, a Na/Pi cotransporter, in rabbit kidney proximal tubules

1993 ◽  
Vol 424 (3-4) ◽  
pp. 210-215 ◽  
Author(s):  
J. Biber ◽  
M. Custer ◽  
A. Werner ◽  
B. Kaissling ◽  
H. Murer
Keyword(s):  
Proximal Tubules ◽  
Rabbit Kidney ◽  
Kidney Proximal Tubules
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