- Author:
- Shelley Fong <sfon036@UoA.auckland.ac.nz>
- Date:
- 2024-10-09 11:41:17+13:00
- Desc:
- Adding water information. Changing file suffix to RST
- Permanent Source URI:
- https://models.physiomeproject.org/workspace/be5/rawfile/6d28674dec5a0ea1dcccddf2e919aac3b8413798/exposure.rst
Kidney
====================
The kidney works by filtering out unwanted solutes from blood in order to make urine, and reabsorbs what is needed in order to maintain homeostasis. A kidney is made up of nephrons receiving blood via the renal artery, and returns the filtered blood to the renal veins.
Water is also reabsorbed through aquaporins along every stage of the nephron, to varying degrees.
The filtered-out urine flows towards the bladder through the ureters.
Pictures
===================
.. figure:: exposure/nephron_pic.png
:width: 50%
:align: center
:alt: nephron
Fig. 1. The nephron
.. csv-table:: Structural abbreviations
:header: Abbreviation, Name
:widths: 5, 9
CD, Collecting Duct
CNT, Connecting Tubule
DCT, Distal Convoluted Tubule
IMCD, Inner Medullary Collecting Duct
JGA, Juxtaglomerular Apparatus
OMCD, Outer Medullary Collecting Duct
PCT, Proximal Convoluted Tubule
TAL, Thick Ascending Limb
tDL, thin Descending Limb
Solute transport
===================
The following list contains the known membrane transporters along the nephron.
.. csv-table:: Transporters along the nephron
:header: Abbrev, Channel name, Location, Membrane, Direction
:widths: 5,6,8, 4, 10
AE1, Anion exchanger 1, PCT/OMCD, A (PCT)/B (OMCD), Cl\ :sup:`-` in/HCO\ :sub:`3`\ :sup:`-` out
CFTR, Cystic fibrosis transmembrane conductance regulator, DCT/CCD/IMCD, B, Cl\ :sup:`-` out
CLC-K, Kidney chloride channel, TAL/DCT/CD, B, Cl\ :sup:`-` out
Cldn 2/12/16/19, Claudin, PCT (Cldn 2/12)/TAL (Cldn 16/19), P, Ca\ :sup:`2+` out
ENaC, Epithelial sodium channel, CNT/CD, A, Na\ :sup:`+` in
Glut1, Glucose transporter 1, late PCT, B, glucose in
Glut2, Glucose transporter 2, early PCT, B, glucose in
H-ATPase, Hydrogen ATPase, PCT/CNT/CD, A, H\ :sup:`+` out
H-K-ATPase, Hydrogen/potassium ATPase, CNT/IMCD/OMCD, A, H\ :sup:`+` out/K\ :sup:`+` in
KCC, K/Cl cotransporter, PCT/TAL/IMCD, B, Cl\ :sup:`-` out/K\ :sup:`+` out
Na-Pi2, Sodium/phosphate cotransporter 2, PCT, A, Na\ :sup:`+` in/PO\ :sub:`4`\ :sup:`2+` in
NCC, Sodium chloride cotransporter, DCT/CNT, A, Na\ :sup:`+` in/Cl\ :sup:`-` in
`NCX1 <https://models.physiomeproject.org/e/bd8>`_, Sodium/calcium exchanger, CNT/DCT, B, Na\ :sup:`+` in/Ca\ :sup:`2+` out
NHE3, Sodium/hydrogen exchanger, PCT/TAL/DST, A, Na\ :sup:`+` in/H\ :sup:`+` out
NHE4, Sodium/hydrogen exchanger, PCT/TAL, A, Na\ :sup:`+` (or NH\ :sub:`4`\ :sup:`+`) in/H\ :sup:`+` out
`NKA <https://models.physiomeproject.org/e/bd7>`_, Sodium/potassium ATPase, throughout, B, 3Na\ :sup:`+` out/2K\ :sup:`+` (or NH\ :sub:`4`\ :sup:`+`) in
NKCC2, Sodium/potassium/chloride cotransporter, TAL, A, Na\ :sup:`+` in/2Cl\ :sup:`-` in\ :sup:`-`/K\ :sup:`+` (or NH\ :sub:`4`\ :sup:`+`) in
`PMCA <https://models.physiomeproject.org/e/bb1>`_, plasma membrane calcium ATPase, PCT/DCT/CNT, B, Ca\ :sup:`2+` out
ROMK, Renal outer medullary potassium channel, TAL/CNT, A, K\ :sup:`+` out
SGLT1, Sodium-glucose cotransporter 1, late PCT, A, Na\ :sup:`+` in/glucose in
SGLT2, Sodium-glucose cotransporter 2, early PCT, A, Na\ :sup:`+` in/glucose in
Solutes: Sodium Na\ :sup:`+`, chloride Cl\ :sup:`-`, potassium K\ :sup:`+`, hydrogen H\ :sup:`+`, bicarbonate HCO\ :sub:`3`\ :sup:`-`, ammonum NH\ :sub:`4`\ :sup:`+`, phosphate PO\ :sub:`4`\ :sup:`2+`
Membrane: **A** apical (to filtrate), **B** basolateral (to blood), **P** paracellular (to interstitial space).
Direction: movement of solute under normal physiological conditions.
Water transport
===================
The following list contains the known aquaporin (AQP) isoforms along the nephron, which transport water across the cell membrane.
.. csv-table:: Aquaporin along the nephron
:header: Location, AQP, Membrane, Direction, Reab
:widths: 6,4, 5, 5, 5
PCT, 1, A, in, " "
" ", 1, B, out, 70
PCT, 7, A, in, " "
tDL, 1, A, in, " "
" ", 1, B, out, 20
CD, 2, A, in, " "
" ", 3, B, out, " "
" ", 4, B, out, 0-9
'Reab' refers to the total water reabsorption amount of the section. 'Direction' is the movement of water relative to the cell the AQP is present in.
Literature
===================
.. csv-table:: For further reading
:header: Title, Author
:widths: 30, 15
"`A mathematical model of the inner medullary collecting duct of the rat: acid/base transport <https://pubmed.ncbi.nlm.nih.gov/6496750/>`_", "Weinstein"
"`Coupling of renal sodium and calcium transport: A modeling analysis <https://www.biorxiv.org/content/10.1101/2023.05.29.542749v1>`_", "Hakimi et al."
"`Renal water transport in health and disease <https://doi.org/10.1007%2Fs00424-022-02712-9>`_", "Feraille et al"
Existing models
===================
.. csv-table:: Link to other PMR workspaces or exposures
:header: "Title"
:widths: 30
"`Na+/H+ Exchanger (NHE3) Model <https://models.physiomeproject.org/e/2e2>`_"
"`Cl-/HCO3- Exchanger (AE1) Model <https://models.physiomeproject.org/e/2ff>`_"
"`H+/K+ ATPase (Weinstein, 1998) <https://models.physiomeproject.org/exposure/632a7aad8db50bce5adf03529cab93c2>`_"
