Sodium-dependent dicarboxylate transport in rat renal basolateral membrane vesicles

1984 ◽  
Vol 401 (3) ◽  
pp. 254-261 ◽  
Author(s):  
Gerhard Burckhardt
Keyword(s):  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Basolateral Membrane Vesicles ◽  
Dicarboxylate Transport ◽  
Sodium Dependent

Decreased transport in renal basolateral membrane vesicles from hypertaurinuric mice

1988 ◽  
Vol 255 (1) ◽  
pp. F88-F95 ◽  
Author(s):  
S. Mandla ◽  
C. R. Scriver ◽  
H. S. Tenenhouse
Keyword(s):  
Inbred Mouse ◽  
Basolateral Membrane ◽  
Inbred Mouse Strain ◽  
Membrane Vesicles ◽  
Temperature Sensitive ◽  
Basolateral Membrane Vesicles ◽  
Sodium Dependent ◽  
Interstrain Difference ◽  
Taurine Uptake

Basolateral membrane vesicles were prepared from mouse kidney by use of a Percoll density gradient method. The preparation was enriched ninefold in Na+-K+-ATPase with minimal contamination by other cellular membranes. The basolateral membranes were a mixture of sealed inside-out and right-side-out vesicles (30%) and leaky vesicles or sheets (70%). Taurine uptake into basolateral membrane vesicles was osmotically sensitive, sodium dependent, temperature sensitive, inhibited by beta-alanine, and saturable (apparent Km, 360 microM; Vmax, 25.4 pmol.mg protein-1.15 s-1), indicating transport by a carrier-mediated process. The function of this transporter was examined in an inbred mouse strain, C57BL/6J, which has selective hypertaurinuria, presumably a result of decreased basolateral membrane permeability to taurine [Rozen et al., Am. J. Physiol. 244 (Renal Fluid Electrolyte Physiol. 13): F150-F155, 1983]. The sodium-dependent component of taurine uptake was significantly lower in C57BL/6J vesicles relative to control (C3H/HeJ strain): 2.9 +/- 0.7 vs. 9.4 +/- 0.3 (SE) pmol.mg protein-1.15 s-1, respectively; P less than 0.001. The interstrain difference in uptake was specific for taurine and could not be ascribed to differences in vesicle purification, integrity, orientation, or size. These findings indicate that the renal basolateral membrane is the site of a transport defect, which explains decreased net taurine reabsorption in vivo in the C57BL/6J strain, and corroborate earlier observations in the renal cortical slice preparation.

Depression of calcium pump activity in renal cortex of vitamin D-deficient rats with secondary hyperparathyroidism

1990 ◽  
Vol 123 (4) ◽  
pp. 438-444 ◽  
Author(s):  
Yusuke Tsukamoto ◽  
Teiichi Tamura ◽  
Michiyo Saitoh ◽  
Yumiko Takita ◽  
Toshiaki Nakano
Keyword(s):  
Vitamin D ◽  
Secondary Hyperparathyroidism ◽  
Hormonal Regulation ◽  
Serum Calcium Level ◽  
Renal Cortex ◽  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Calcium Pump ◽  
Basolateral Membrane Vesicles ◽  
Pump Activity

Abstract. To examine the hormonal regulation of the ATP-dependent Ca2+ pump in the kidneys, the ATP-dependent Ca2+ uptake by the basolateral membrane vesicles in the renal cortex was measured using radioactive calcium (45Ca2+) in rats with vitamin D deficiency or rats undergoing thyroparathyroidectomy. The Vmax of the Ca2+ pump activity was increased not only by administering calcitriol, but also by normalizing the serum calcium level in vitamin D-deficient rats. PTH suppressed the Ca2+ pump activity in normocalcemic vitamin D-deficient rats. Thyroparathyroidectomy did not affect the Ca2+ pump activity in the kidneys of normal rats. It was concluded that the ATP-dependent Ca2+ pump activity was depressed by secondary hyperparathyroidism in vitamin D-deficient rats.

scholarly journals Characterization of sodium-dependent and sodium-independent nucleoside transport systems in rabbit brush-border and basolateral plasma-membrane vesicles from the renal outer cortex

1989 ◽  
Vol 264 (1) ◽  
pp. 223-231 ◽  
Author(s):  
T C Williams ◽  
A J Doherty ◽  
D A Griffith ◽  
S M Jarvis
Keyword(s):  
Brush Border ◽  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Nucleoside Transport ◽  
Transport Systems ◽  
Facilitated Diffusion ◽  
Basolateral Membrane Vesicles ◽  
Plasma Membrane Vesicles ◽  
Outer Cortex ◽  
Overshoot Phenomenon

The transport of uridine into rabbit renal outer-cortical brush-border and basolateral membrane vesicles was compared at 22 degrees C. Uridine was taken up into an osmotically active space in the absence of metabolism for both types of membrane vesicles. Uridine influx by brush-border membrane vesicles was stimulated by Na+, and in the presence of inwardly directed gradients of Na+ a transient overshoot phenomenon was observed, indicating active transport. Kinetic analysis of the saturable Na+-dependent component of uridine flux indicated that it was consistent with Michaelis-Menten kinetics (Km 12 +/- 3 microM, Vmax. 3.9 +/- 0.9 pmol/s per mg of protein). The sodium:uridine coupling stoichiometry was found to be consistent with 1:1 and involved the net transfer of positive charge. In contrast, uridine influx by basolateral membrane vesicles was not dependent on the cation present and was inhibited by nitrobenzylthioinosine (NBMPR). NBMPR-sensitive uridine transport was saturable (Km 137 +/- 20 microM, Vmax. 5.2 +/- 0.6 pmol/s per mg of protein). Inhibition of uridine flux by NBMPR was associated with high-affinity binding of NBMPR to the basolateral membrane (Kd 0.74 +/- 0.46 nM). Binding of NBMPR to these sites was competitively blocked by adenosine and uridine. These results indicate that uridine crosses the brush-border surface of rabbit proximal renal tubule cells by Na+-dependent pathways, but permeates the basolateral surface by NBMPR-sensitive facilitated-diffusion carriers.

Urate transport in the proximal tubule: in vivo and vesicle studies

1985 ◽  
Vol 249 (6) ◽  
pp. F789-F798 ◽  
Author(s):  
A. M. Kahn ◽  
E. J. Weinman
Keyword(s):  
Proximal Tubule ◽  
Brush Border ◽  
Anion Exchanger ◽  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Transport Processes ◽  
Basolateral Membrane Vesicles ◽  
Urate Transport ◽  
Rat Proximal Tubule

The transport of urate in the mammalian nephron is largely confined to the proximal tubule. Depending on the species, net reabsorption or net secretion is observed. The rat, like the human and the mongrel dog, demonstrates net reabsorption of urate and has been the most extensively studied species. The unidirectional reabsorption and secretion of urate in the rat proximal tubule occur via a passive and presumably paracellular route and by a mediated transcellular route. The reabsorption of urate, and possibly its secretion, can occur against an electrochemical gradient. A variety of drugs and other compounds affect the reabsorption and secretion of urate. The effects of these agents depend on their site of application (luminal or blood), concentration, and occasionally their participation in transport processes that do not have affinity for urate. Recent studies with renal brush border and basolateral membrane vesicles from the rat and brush border vesicles from the dog have determined the mechanisms for urate transport across the luminal and antiluminal membranes of the proximal tubule cell. Brush border membrane vesicles contain an anion exchanger with affinity for urate, hydroxyl ion, bicarbonate, chloride, lactate, p-aminohippurate (PAH), and a variety of other organic anions. Basolateral membrane vesicles contain an anion exchanger with affinity for urate and chloride but not for PAH. Both membrane vesicle preparations also permit urate translocation by simple diffusion. A model for the transcellular reabsorption and secretion of urate in the rat proximal tubule is proposed. This model is based on the vesicle studies, and it can potentially explain the majority of urate transport data obtained with in vivo techniques.

K-Cl transport systems in rabbit renal basolateral membrane vesicles

1987 ◽  
Vol 252 (5) ◽  
pp. F883-F889 ◽  
Author(s):  
J. Eveloff ◽  
D. G. Warnock
Keyword(s):  
Carboxylic Acid ◽  
Renal Cortex ◽  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Chloride Conductance ◽  
Transport Systems ◽  
Basolateral Membrane Vesicles ◽  
Transport Pathways ◽  
System A ◽  
Potassium Gradient

The transport pathways for chloride in basolateral membrane vesicles from the rabbit renal cortex were investigated. 36Cl uptake was stimulated by the presence of potassium in the uptake media compared with sodium or N-methyl-D-glucamine. In addition, potassium (86Rb) uptake was stimulated more by chloride than by nitrate or gluconate. Neither of these processes was further stimulated by potassium gradients plus valinomycin, suggesting the presence of an electrically neutral K-Cl cotransport system. A magnesium-induced chloride conductance was also found in the basolateral membrane vesicles. In the absence of magnesium, the chloride conductance was low; valinomycin and an inwardly directed potassium gradient did not stimulate 36Cl uptake, anthracene-9-carboxylic acid did not inhibit 36Cl uptake, and valinomycin did not stimulate chloride-dependent 86Rb uptake. However, in the presence of 1 mM magnesium, opposite results were obtained; valinomycin and an inwardly directed potassium gradient stimulated 36Cl uptake, anthracene-9-carboxylic acid inhibited 36Cl uptake, and valinomycin stimulated chloride-dependent 86Rb uptake. Therefore, an electrically neutral K-Cl cotransport and magnesium-induced chloride conductance were found in renal cortical basolateral membrane vesicles prepared from the rabbit renal cortex.

Sign in / Sign up

Export Citation Format

Share Document