N-ethyl-N-nitrosourea mutagenesis produced a small number of mice with altered plasma electrolyte levels

Here, we retrospectively evaluated the use of the plasma electrolytes calcium, chloride, inorganic phosphorus, potassium and sodium in the Munich ENU mouse mutagenesis project where clinical chemical blood analysis was carried out on more than 20,000 G1 and G3 offspring of chemically mutagenized inbred C3H mice to detect dominant and recessive mutations leading to deviations in various plasma parameter levels.We identified a small number of animals consistently exhibiting altered plasma electrolyte values. Transmission of the phenotypic deviations to the subsequent generations led to the successful establishment of mutant lines for the parameters calcium and potassium. Published data from other phenotype-driven ENU projects also included only a small number of mutant lines which were generated according to altered plasma electrolyte levels.Thus, use of plasma electrolytes detected few mouse mutants in ENU projects compared to other clinical chemical blood parameters.Clinical chemical plasma analyses are often used in the medical examination of patients for the diagnosis of the involvement of various organs as well as for the evaluation of therapeutic strategies in multifactorial and polygenic human diseases. Electrolytes including calcium, chloride, inorganic phosphorus, potassium and sodium are routine parameters in these analyses. The diagnostic impact of plasma electrolyte values includes the general maintenance of osmotic pressure, water distribution and acid-base equilibrium (Na, Cl, K) as well as tissue-specific metabolism and organ function, especially of bone and kidney. Comparison of intracellular versus extracellular distribution of the electrolytes reveals that K is the chief intracellular cation, therefore, measured plasma K values are increased in the case of hemolysis or cellular stress like muscle trauma (Table 1). Together with the results of other diagnostic parameters, plasma electrolytes contribute to the identification of the impaired organ funct