ArticleBiology open2025
Ammonia transport mediated by urea transporter A isoforms.
Article in Biology open, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
4 authors.
Funding
Abstract
Urea transporters (UTs) are a family of urea-selective channel proteins that play an essential role in the urine-concentrating mechanism of the mammalian kidney. In addition to urea, UT-A2 and UT-A3 - the N- and C-terminal regions of full-length UT-A1, respectively - and UT-B transport water, and human UT-B transports water and ammonia (NH3). However, UT-A-mediated NH3 transport has not been evaluated. Given that regulated renal NH3/NH4+ transport by renal epithelial cells is essential to acid-base homeostasis and considering UT-A2 and UT-A3 localization in the inner medulla, where the transport of urea, water, and NH3 is important, it is plausible that UT-A-mediated NH3 transport could be physiologically relevant. The present study characterized the urea, water, and NH3 transport properties and solute pathways of murine UT-A2, UT-A3, and UT-B heterologously expressed in Lithobates catesbeianus oocytes. Control and UT-expressing oocytes were evaluated for surface protein expression through lysine-biotinylation and immunoblotting. Urea uptake was measured using radiolabeled urea, water permeability was assessed using video microscopy, and NH3 transport was monitored using a surface pH microelectrode. All UT-encoding cRNAs were translated, glycosylated, and inserted into the oocyte membrane. Wild-type UT-expressing oocytes displayed significantly higher urea, water, and NH3 transport than day-matched water-injected control cells. Pre-treating the oocytes with phloretin or mutating the urea pore threonines (Thr177 and Thr339 human UT-B numbering) to valines (Val) attenuated UT-mediated urea, water and NH3 transport to control oocyte values. Our study showed for the first time that UT-A2 and UT-A3 increase the membrane NH3 permeability. Thus, besides the critical role of UTs in urinary concentration, these proteins may also impact acid-base homeostasis and contribute to other processes associated with health and disease.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.