Activation of Calcium-Dependent K Channels by Parathyroid Hormone in Rabbit Proximal Convoluted Tubules in Culture1

2015 ◽  
pp. 229-236
Author(s):  
Aiichiro Ogawa ◽  
Katsumasa Kawahara ◽  
Makoto Suzuki ◽  
Osamu Sakai
Keyword(s):  
Parathyroid Hormone ◽  
K Channels ◽  
Calcium Dependent ◽  
Convoluted Tubules ◽  
Proximal Convoluted Tubules

PTH inhibition of bicarbonate transport by proximal convoluted tubules

1980 ◽  
Vol 239 (2) ◽  
pp. F127-F134 ◽  
Author(s):  
T. D. McKinney ◽  
P. Myers
Keyword(s):  
Parathyroid Hormone ◽  
Cyclic Amp ◽  
Co2 Concentration ◽  
Bicarbonate Transport ◽  
Co2 Absorption ◽  
Fluid Absorption ◽  
Dibutyryl Cyclic Amp ◽  
Convoluted Tubules ◽  
Proximal Convoluted Tubules

These studies examined the effect of parathyroid hormone (PTH), dibutyryl cyclic AMP DBcAMP, and 8-bromo-cyclic AMP BrcAMP on HCO3- transport by rabbit superficial proximal convoluted tubules perfused in vitro. Bicarbonate was estimated as total CO2 measured microcalorimetrically. At slow perfusion rates with 25 mM HCO3- in the perfusate and bath, PTH (0.1 U/ml in the bath) caused the total CO2 in tubular fluid to rise from 10.2 to 19.9 mM. The hormone had no effect on the total CO2 concentration in tubules perfused with HCO3(-)-free perfusates. With HCO3(-) in the perfusate and bath, PTH reduced the rates of fluid and total CO2 absorption to 57 and 48% of control values, respectively. PTH had no effect on the rates of fluid absorption and total CO2 secretion when HCO3(-)-free perfusates were used. The effects of DBcAMP and BrcAMP (10(-7) M in the bath) were similar to those of PTH. 5'-AMP (10(-6) M in the bath) did not alter the total CO2 concentration of tubular fluid when the tubules were perfused at slow rates with HCO3- in the perfusate and bath. Ouabain (10(-5) M in the bath) caused the total CO2 concentration in tubules perfused at slow rates with HCO3--free perfusates to rise from 8.9 to 12.7 mM. PTH caused no further change in the total CO2 concentration in the presence of ouabain.

Patch clamp study on primary culture of isolated proximal convoluted tubules

1988 ◽  
Vol 413 (1) ◽  
pp. 51-61 ◽  
Author(s):  
J. Merot ◽  
M. Bidet ◽  
B. Gachot ◽  
S. Le Maout ◽  
M. Tauc ◽  
...  
Keyword(s):  
Patch Clamp ◽  
Primary Culture ◽  
Clamp Study ◽  
Convoluted Tubules ◽  
Proximal Convoluted Tubules

The effect of short term exposures to 100% oxygen on the fine structure of proximal convoluted tubules

1970 ◽  
Vol 26 (10) ◽  
pp. 1124-1125 ◽  
Author(s):  
R. T. Hess ◽  
D. B. Menzel
Keyword(s):  
Fine Structure ◽  
Short Term ◽  
Convoluted Tubules ◽  
Proximal Convoluted Tubules

scholarly journals 1085 ESTIMATION OF INTRACELLULAR MACROMOLECULAR OSMOTIC PRESSURE OF RENAL PROXIMAL CONVOLUTED TUBULES (PCT)

1978 ◽  
Vol 12 ◽  
pp. 544-544
Author(s):  
Michael A Linshaw ◽  
F Bruder Stapleton
Keyword(s):  
Osmotic Pressure ◽  
Convoluted Tubules ◽  
Proximal Convoluted Tubules

Lipoid Substance in the Cells of Proximal Convoluted Tubules of the Kidneys of Young Rats on a Choline-deficient Diet

Science ◽  
1947 ◽  
Vol 105 (2725) ◽  
pp. 315-315 ◽  
Author(s):  
W. S. HARTROFT ◽  
C. H. BEST
Keyword(s):  
Deficient Diet ◽  
Young Rats ◽  
Convoluted Tubules ◽  
Proximal Convoluted Tubules

Organic solutes in fluid absorption by renal proximal convoluted tubules

1976 ◽  
Vol 231 (2) ◽  
pp. 627-637 ◽  
Author(s):  
M Burg ◽  
C Patlak ◽  
N Green ◽  
D Villey
Keyword(s):  
Epithelial Cell ◽  
Organic Solutes ◽  
Fluid Absorption ◽  
Transepithelial Voltage ◽  
Convoluted Tubules ◽  
Proximal Convoluted Tubules

Proximal convoluted tubules were dissected from rabbit kidneys and perfused with artificial solutions in vitro. The effect of various organic solutes on rate of fluid absorption and transepithelial voltage was tested by removing solutes from or adding them to perfusate and/or bath. Omission of albumin from the bath caused rate of fluid absorption to descrease 33% without any change in voltage. Omission of glucose, lactate, alanine, and citrate from the bath had no effect. In contrast, when they were removed from perfusate, rate of fluid absorption fell by 45-75% (depending on whether they were replaced by NaCl or mannitol and NaCl), and voltage (normally negative in lymen) decreased to near zero. Adding glucose or alanine individually to perfusate caused a small increase in rate of fluid absorption and a relatively large increase in voltage. alpha-Methyl-D-glucoside and cycloleucine (which are transported but not metabolized) had effects similar to glucose and alanine, except that voltage changes were not as great. Phlorizin (10(-5) M in perfusate) had the same effect as removing glucose from perfusate. When glucose and alanine were added to perfusate, epithelial cell swelled significantly. Lactate and citrate also caused rate of fluid absorption to increase when they were added to perfusate, but they did not affect transepithelial voltage nor did they cause cells to swell significantly. Possible mechanisms of these effects and the role of organic solutes in fluid absorption by proximal convoluted tubules are discussed.

Calcium-Dependent Intracellular Degradation of Parathyroid Hormone: A Possible Mechanism for the Regulation of Hormone Stores12

Endocrinology ◽  
1975 ◽  
Vol 97 (2) ◽  
pp. 431-441 ◽  
Author(s):  
JOEL F. HABENER ◽  
BYRON KEMPER ◽  
JOHN T. POTTS
Keyword(s):  
Parathyroid Hormone ◽  
Calcium Dependent ◽  
Intracellular Degradation

scholarly journals HISTOCHEMICAL STUDIES ON THE UPTAKE OF HORSERADISH PEROXIDASE BY RAT KIDNEY SLICES

1965 ◽  
Vol 27 (2) ◽  
pp. 305-312 ◽  
Author(s):  
A. T. Miller ◽  
D. M. Hale ◽  
K. D. Alexander
Keyword(s):  
Horseradish Peroxidase ◽  
Intracellular Transport ◽  
Rat Kidney ◽  
Kidney Slices ◽  
Metabolic Conditions ◽  
Peroxidase Uptake ◽  
Free Media ◽  
Energy Dependent ◽  
Convoluted Tubules ◽  
Proximal Convoluted Tubules

When rat kidney slices were incubated in the presence of horseradish peroxidase, there was an energy-dependent uptake of the protein by the cells of the kidney tubules. The uptake was greatest in the proximal convoluted tubules and in the thick ascending limbs of the loops of Henle; it was abolished by cold, anoxia, 2,4-dinitrophenol, and fluoroacetate, and was more readily depressed by unfavorable metabolic conditions in the proximal convoluted tubules than in the thick ascending limbs. Protein uptake was inhibited when the kidney slices were incubated in electrolyte-free media. In sodium chloride solutions, uptake was reduced as sodium was progressively replaced by choline, and ouabain inhibited uptake in the proximal convoluted tubules, but not in the thick ascending limbs. To a limited extent, lithium could replace sodium in the incubation medium with no depression of peroxidase uptake. These results suggest that a sodium-stimulated, ouabain-sensitive ATPase may be involved in the uptake of protein by cells of the kidney tubule. The intracellular transport of peroxidase in cells of the proximal convoluted tubules was abolished by cold, anoxia, and 2,4-dinitrophenol, but it was not affected by concentrations of ouabain which inhibited the uptake of the protein.

scholarly journals The Receptor for Parathyroid Hormone and Parathyroid Hormone-Related Peptide Is Hydrolyzed and Its Signaling Properties Are Altered by Directly Binding the Calpain Small Subunit

Endocrinology ◽  
2005 ◽  
Vol 146 (5) ◽  
pp. 2336-2344 ◽  
Author(s):  
Masako Shimada ◽  
Matthew J. Mahon ◽  
Peter A. Greer ◽  
Gino V. Segre
Keyword(s):  
Parathyroid Hormone ◽  
Fluorescent Protein ◽  
Yellow Fluorescent Protein ◽  
Small Subunit ◽  
Hek293 Cells ◽  
Calpain Inhibitor ◽  
Dependent Manner ◽  
Intact Cells ◽  
Calcium Dependent

Abstract We show calcium-dependent, direct binding between the N-terminal portion of the PTH/PTHrP receptor (PTH1R) C-terminal intracellular tail and the calpain small subunit. Binding requires, but may not be limited to, amino acids W474, S475, and W477. The wild-type, full-length rat (r) PTH1R, but not rPTH1R with W474A/W477A substitutions, copurifies with the endogenous calpain small subunit in HEK293 cells. Calpain hydrolyzes ΔNt-rPTH1R, a receptor with a 156-amino acid N-terminal deletion, in a calcium-dependent manner in vitro and in intact cells. Most importantly, PTH stimulation increases the cleavage of ΔNt-rPTH1R and rPTH1R-yellow fluorescent protein in HEK293 cells, and of talin in HEK293 cells expressing rPTH1R-yellow fluorescent protein and in ROS17/2.8 osteoblast-like cells that express rPTH1R endogenously. The absence of calpain in Capn4-null embryonic fibroblasts and the lowered calpain activity in MC3T3-E1 osteoblastic cells due to stable expression of the calpain inhibitor, calpastatin, reduce PTH-stimulated cAMP accumulation. The calpain small subunit is the second protein, in addition to the sodium-hydrogen exchanger regulatory factor, and the first enzyme that binds the PTH1R; PTH1R bound to both of these proteins results in altered PTH signaling.

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