The Na+-HCO 3 ? cotransporter operates with a coupling ratio of 2 HCO 3 ? to 1 Na+ in isolated rabbit renal proximal tubule

1993 ◽  
Vol 425 (5-6) ◽  
pp. 409-416 ◽  
Author(s):  
G. Seki ◽  
S. Coppola ◽  
E. Fr�mter
Keyword(s):  
Proximal Tubule ◽  
Renal Proximal Tubule ◽  
Coupling Ratio

scholarly journals Rheogenic transport in the renal proximal tubule.

1983 ◽  
Vol 82 (6) ◽  
pp. 819-851 ◽  
Author(s):  
H Sackin ◽  
E L Boulpaep
Keyword(s):  
Cell Membrane ◽  
Proximal Tubule ◽  
Basolateral Membrane ◽  
Electrical Potential ◽  
Renal Proximal Tubule ◽  
Coupling Ratio ◽  
Electrical Equivalent Circuit ◽  
Nernst Potential ◽  
Intracellular Na Activity ◽  
Activity Measurements

The electrophysiology of the renal Na-K ATPase was studied in isolated perfused amphibian proximal tubules during alterations in bath (serosal) potassium. Intracellular and extracellular ionic activity measurements permitted continuous evaluation of the Nernst potentials for Na+, K+, and Cl- across the basolateral membrane. The cell membrane and transepithelial potential differences and resistances were also determined. Return of K to the basal (serosal) solution after a 20-min incubation in K-free solution hyperpolarized the basolateral membrane to an electrical potential that was more negative than the Nernst potential for either Na, Cl, or K. This constitutes strong evidence that at least under stimulated conditions the Na-K ATPase located at the basolateral membrane of the renal proximal tubule mediates a rheogenic process which directly transfers net charge across the cell membrane. Interpretation of these data in terms of an electrical equivalent circuit permitted calculation of both the rheogenic current and the Na/K coupling ratio of the basolateral pump. During the period between 1 and 3 min after pump reactivation by return of bath K, the basolateral rheogenic current was directly proportional to the intracellular Na activity, and the pump stoichiometry transiently exceeded the coupling ratio of 3Na to 2K reported in other preparations.

The Fine Structure of Rat Renal Microbodies and Cytoplasmic Bodies Following Perfusion Fixation

1973 ◽  
Vol 31 ◽  
pp. 620-621
Author(s):  
J. M. Barrett ◽  
P. M. Heidger
Keyword(s):  
Fine Structure ◽  
Proximal Tubule ◽  
Rat Kidney ◽  
Renal Proximal Tubule ◽  
Convincing Evidence ◽  
Cytoplasmic Bodies ◽  
Rat Renal Proximal Tubule ◽  
Renal Proximal Tubule Cells ◽  
Perfusion Fixation

Microbodies have received extensive morphological and cytochemical investigation since they were first described by Rhodin in 1954. To our knowledge, however, all investigations of microbodies and cytoplasmic bodies of rat renal proximal tubule cells have employed immersion fixation. Tisher, et al. have shown convincing evidence of fine structural alteration of microbodies in rhesus monkey kidney following immersion fixation; these alterations were not encountered when in vivo intravascular perfusion was employed. In view of these studies, and the fact that techniques for perfusion fixation have been established specifically for the rat kidney by Maunsbach, it seemed desirable to employ perfusion fixation to study the fine structure and distribution of microbodies and cytoplasmic bodies within the rat renal proximal tubule.

Roles of Renal Proximal Tubule Transport in the Pathogenesis of Hypertension

2013 ◽  
Vol 9 (2) ◽  
pp. 148-155 ◽  
Author(s):  
Shoko Horita ◽  
George Seki ◽  
Hideomi Yamada ◽  
Masashi Suzuki ◽  
Kazuhiko Koike ◽  
...  
Keyword(s):  
Proximal Tubule ◽  
Renal Proximal Tubule

scholarly journals Renal Proximal Tubule Cell Cannabinoid-1 Receptor Regulates Bone Remodeling and Mass via a Kidney-to-Bone Axis

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 414
Author(s):  
Saja Baraghithy ◽  
Yael Soae ◽  
Dekel Assaf ◽  
Liad Hinden ◽  
Shiran Udi ◽  
...  
Keyword(s):  
Bone Mass ◽  
Proximal Tubule ◽  
Bone Remodeling ◽  
Kidney Function ◽  
Bone Cells ◽  
Critical Role ◽  
Renal Proximal Tubule ◽  
Proximal Tubule Cell ◽  
Protective Effects ◽  
Cannabinoid 1 Receptor

The renal proximal tubule cells (RPTCs), well-known for maintaining glucose and mineral homeostasis, play a critical role in the regulation of kidney function and bone remodeling. Deterioration in RPTC function may therefore lead to the development of diabetic kidney disease (DKD) and osteoporosis. Previously, we have shown that the cannabinoid-1 receptor (CB1R) modulates both kidney function as well as bone remodeling and mass via its direct role in RPTCs and bone cells, respectively. Here we employed genetic and pharmacological approaches that target CB1R, and found that its specific nullification in RPTCs preserves bone mass and remodeling both under normo- and hyper-glycemic conditions, and that its chronic blockade prevents the development of diabetes-induced bone loss. These protective effects of negatively targeting CB1R specifically in RPTCs were associated with its ability to modulate erythropoietin (EPO) synthesis, a hormone known to affect bone mass and remodeling. Our findings highlight a novel molecular mechanism by which CB1R in RPTCs remotely regulates skeletal homeostasis via a kidney-to-bone axis that involves EPO.

scholarly journals Generation and characterization of iPSC-derived renal proximal tubule-like cells with extended stability

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vidya Chandrasekaran ◽  
Giada Carta ◽  
Daniel da Costa Pereira ◽  
Rajinder Gupta ◽  
Cormac Murphy ◽  
...  
Keyword(s):  
Proximal Tubule ◽  
Retinoic Acid Receptor ◽  
Renal Proximal Tubule ◽  
Whole Body ◽  
Proper Function ◽  
Genome Wide ◽  
Glomerular Filtrate ◽  
Proximal Tubular ◽  
Induced Pluripotent

AbstractThe renal proximal tubule is responsible for re-absorption of the majority of the glomerular filtrate and its proper function is necessary for whole-body homeostasis. Aging, certain diseases and chemical-induced toxicity are factors that contribute to proximal tubule injury and chronic kidney disease progression. To better understand these processes, it would be advantageous to generate renal tissues from human induced pluripotent stem cells (iPSC). Here, we report the differentiation and characterization of iPSC lines into proximal tubular-like cells (PTL). The protocol is a step wise exposure of small molecules and growth factors, including the GSK3 inhibitor (CHIR99021), the retinoic acid receptor activator (TTNPB), FGF9 and EGF, to drive iPSC to PTL via cell stages representing characteristics of early stages of renal development. Genome-wide RNA sequencing showed that PTL clustered within a kidney phenotype. PTL expressed proximal tubular-specific markers, including megalin (LRP2), showed a polarized phenotype, and were responsive to parathyroid hormone. PTL could take up albumin and exhibited ABCB1 transport activity. The phenotype was stable for up to 7 days and was maintained after passaging. This protocol will form the basis of an optimized strategy for molecular investigations using iPSC derived PTL.

Effects of TCDD and estradiol-17β on the proliferation and Na+/glucose cotransporter in renal proximal tubule cells

2005 ◽  
Vol 19 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Ho Jae Han ◽  
Min Jin Lim ◽  
Yun Jung Lee ◽  
Eun Jung Kim ◽  
Young Jin Jeon ◽  
...  
Keyword(s):  
Proximal Tubule ◽  
Renal Proximal Tubule ◽  
Proximal Tubule Cells ◽  
Tubule Cells ◽  
Renal Proximal Tubule Cells ◽  
Estradiol 17Β
Sign in / Sign up

Export Citation Format

Share Document