Volume regulation of muscle cells in the carp Cyprinus carpio in response to hypernatremia

Abstract

BACKGROUND: Hypernatremia supports the movement of water from the intracellular to the intercellular space. This shift leads to cells shrinkage and disruption of intracellular processes, representing risk factors of morbidity and mortality in clinical circumstances. On the other hand, hypernatremia triggers protective mechanisms that counteract damage of cells. OBJECTIVES: To determine in experiments in vivo the ranges of sodium content regulation in the blood plasma of carp characterizing the norm and hypernatremia. To identify the patterns volume regulation of skeletal muscles cells in response to hypernatremia. METHODS: Carps were acclimating for 3 weeks to a different salinity in the range of 0-12 g/L. In the plasma and muscle tissue the concentration of sodium, potassium, calcium and magnesium was determined by the method of fl ame spectrophotometry. Water content in the muscles has been additionally determined. RESULTS: Carps acclimated in the salinity range of 0-6 g/L, maintained the concentration of sodium in blood plasma within of the range of 129-135 mmol/L (normonatremia). In the salinity zone of 6-12 g/L concentration of sodium in the blood plasma of fi sh has increased to 207 mmol/L (hypernatremia). Hypernatremia was causing the increase of the sodium, potassium, calcium and magnesium content in carp muscles and the drop of water level. CONCLUSIONS: Muscle tissue of carp adapts to hypernatremia by means of increasing inorganic ions by 70.8 % and organic osmolytes by 29.2 % (Fig. 2, Ref. 51).

Goldfish as a model for studying the effect of hypernatremia on blood plasma lipoproteins

“…Goldfi sh tolerates water salinity to 6.0 g/L without pronounced signs of stress (29). At water salinity in the range of 8.0-10.0 g/L and up to the upper limit of tolerable salinity (CS), the concentration of Na + in the plasma of goldfi sh and other freshwater Teleostei rises from ~ 150 to 200 mmol/kg, the level of cortisol in the blood is elevated, signs of muscle dehydration appear, along with a decreased locomotor activity and growth rates, decreased urine volume, and increased water consumption (18,19,20,21,27,28,29,30,31,32,33).…”

“…The range of plasma sodium concentration in freshwater teleosts is comparable to that of mammals (18,19). In the conditions of extremely high critical water salinity (CS) tolerated by fi sh, the sodium concentration in their plasma increases to ~190 -206 mmol/kg (10,18,20).…”

Regulation ranges and patterns of adaptation to hyponatremia by cells of various organs and tissues of vertebrate animals

“…Based on the summarized data, it has been demonstrated that the concentration of sodium in the blood plasma of healthy people is maintained within the range of 130-145 mmol/L (3). With regard to the norm, the concentration of sodium in the blood plasma of hospitalized patients decreased to 110 mmol/L (8), 108 mmol/L (6,9), 106 mmol/L (5), 104 mmol/L (7), 98 mmol/L (4), 96 mmol/L (19), or 93 mmol/L (13).…”