What question did this study set out to answer?

To characterize the mechanisms and kinetics of beta-alanine transport across luminal membrane vesicles isolated from the convoluted and straight segments of the rabbit proximal tubule.

April 1, 1989The Journal of PhysiologyOpen Access

Demonstration of H+‐ and Na+‐coupled co‐transport of beta‐alanine by luminal membrane vesicles of rabbit proximal tubule.

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To characterize the mechanisms and kinetics of beta-alanine transport across luminal membrane vesicles isolated from the convoluted and straight segments of the rabbit proximal tubule.
Isolated luminal brush-border membrane vesicles from the rabbit proximal convoluted tubule (pars convoluta) and proximal straight tubule (pars recta).
Measured beta-alanine uptake in the presence and absence of sodium (Na+) and proton (H+) gradients, alongside competitive uptake assays with taurine and alpha-amino acids.
Vesicles from pars convoluta exhibited both a Na+-dependent system (half-saturation 2.7 mM) and an uphill, Na+-independent system driven by an outward-directed H+ gradient.
Vesicles from pars recta relied entirely on Na+ gradients via a dual transport system consisting of a high-affinity pathway (half-saturation 0.16 mM) and a low-affinity pathway (half-saturation 9.3 mM).
Na+-gradient-dependent uptake of beta-alanine was competitively inhibited by taurine in both segments, whereas alpha-amino acids caused no appreciable inhibition.

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Implication

In vitro study reveals distinct proton- and sodium-coupled beta-alanine transport across rabbit proximal tubule membranes, highlighting specialized pathways for renal beta-amino acid reabsorption.

Cite This Study

Jessen et al. (1989) studied this question.

synapsesocial.com/papers/6aa76bd5d395d5537273fa85 https://doi.org/10.1113/jphysiol.1989.sp017587

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Implication

In vitro study reveals distinct proton- and sodium-coupled beta-alanine transport across rabbit proximal tubule membranes, highlighting specialized pathways for renal beta-amino acid reabsorption.

Demonstration of H+‐ and Na+‐coupled co‐transport of beta‐alanine by luminal membrane vesicles of rabbit proximal tubule.

Key Points

Discussion

Implication

Cite This Study

Demonstration of H+‐ and Na+‐coupled co‐transport of beta‐alanine by luminal membrane vesicles of rabbit proximal tubule.

Key Points

Discussion

Implication

Cite This Study

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