Effects of high potassium chloride supplementation on water intake and bodyweight gains in pregnant and lactating mice

Thirty‐one ICR pregnant mice were assigned to a control or a potassium chloride (KCl) diet group to clarify the effects of KCl supplementation on water intake, bodyweight gains and serum components in pregnant and lactating mice, and 5% KCl was supplemented in KCl diets from 6.5 days post coitus to 1 or 14 days after parturition. Feed intake was not affected by treatment, but supplemental KCl decreased bodyweight gains of lactating mice and their neonatal mice. Water intake and urine volume of KCl supplemented mice were significantly higher than those of control mice during pregnancy and supplemental KCl decreased serum urea N in pregnant mice. Supplemental KCl increased water intake drastically in lactating mice immediately after parturition and increased serum K at 14 days after parturition. Histological alteration using hematoxylin–eosin was not found in the kidney of each mouse at 1 or 14 days after parturition. These results indicate that high KCl supplementation accelerates water intake in lactating mice and prevents bodyweight gains of maternal and neonatal mice during lactation.