10.6084/m9.figshare.5484223.v1
Schmidt K.
Schmidt
K.
Ripper M.
Ripper
M.
Tegtmeier I.
Tegtmeier
I.
Humberg E.
Humberg
E.
Sterner C.
Sterner
C.
Reichold M.
Reichold
M.
Warth R.
Warth
R.
Bandulik S.
Bandulik
S.
Supplementary Material for: Dynamics of Renal Electrolyte Excretion in Growing Mice
Karger Publishers
2017
Genetically modified mice
Growing mice
Postnatal dynamics
Renal electrolyte excretion
2017-10-10 11:23:53
Journal contribution
https://karger.figshare.com/articles/journal_contribution/Supplementary_Material_for_Dynamics_of_Renal_Electrolyte_Excretion_in_Growing_Mice/5484223
<p>Genetically modified mice represent important models for elucidating
renal pathophysiology, but gene deletions frequently cause severe
failure to thrive. In such cases, the analysis of the phenotype is often
limited to the first weeks of life when renal excretory function
undergoes dramatic physiological changes. Here, we investigated the
postnatal dynamics of urinary ion excretion in mice. The profiles of
urinary electrolyte excretion of mice were examined from birth until
after weaning using an automated ion chromatography system. Postnatally,
mice grew about 0.4 g/day, except during two phases with slower weight
gain: (i) directly after birth during adaptation to extrauterine
conditions (P0-P2) and (ii) during the weaning period (P15-P21), when
nutrition changed from mother's milk to solid chow and water. During the
first 3 days after birth, remarkable changes in urinary Na<sup>+</sup>, Ca<sup>2+</sup>, Mg<sup>2+</sup>, and phosphate concentrations occurred, whereas K<sup>+</sup> and Cl<sup>-</sup> concentrations hardly changed. From days 4-14 after birth, Na<sup>+</sup>, Ca<sup>2+</sup>, Mg<sup>2+</sup>, K<sup>+</sup>, and Cl<sup>-</sup> concentrations remained relatively stable at low levels. Urinary concentrations of creatinine, NH<sub>4</sub><sup>+</sup>, phosphate, and sulfate constantly increased from birth until after weaning. Profiles of salt excretion in KCNJ10<sup>-/-</sup>
mice exemplified the relevance of age-dependent analysis of urinary
excretion. In conclusion, the most critical phases for analysis of renal
ion excretion during the first weeks of life are directly after birth
and during the weaning period. The age dependence of urinary excretion
varies for the different ions. This should be taken into consideration
when the renal phenotype of mice is investigated during the first weeks
of life.</p>