Potassium loss with tissue potassium deficiency in rats during hypokinesia

This study aims at showing the effect of hypokinesia (HK) on tissue potassium (K(+)) loss with different tissue K(+) depletion and tissue K(+) deficiency with different K(+) intake. To this end, tissue K(+) content, plasma K(+) level, and K(+) loss with and without K(+) supplements during HK were measured.

Studies were conducted on male Wistar rats during a pre-experimental and an experimental period. Animals were equally divided into four groups: unsupplemented vivarium control rats (UVCR), unsupplemented hypokinetic rats (UHKR), supplemented vivarium control rats (SVCR), and supplemented hypokinetic rats (SHKR). SVCR and SHKR were supplemented daily with 2.50 mEq potassium chloride (KCl).

Gastrocnemius muscle and right femur bone K(+) content reduced significantly, whereas plasma K(+) level and urine and fecal K(+) loss increased significantly in SHKR and UHKR compared with their pre-experimental values and the values in their respective vivarium controls (SVCR and UVCR). Bone and muscle K(+) content decreased more significantly, and plasma K(+) level and urine and fecal K(+) loss increased more significantly in SHKR than in UHKR.

The greater tissue K(+) deficiency with higher than lower K(+) intake shows that the risk of higher tissue K(+) deficiency is directly related to K(+) intake. The higher K(+) loss with higher tissue K(+) deficiency and the lower K(+) loss with lower K(+) tissue deficiency shows that the risk of greater K(+) loss is directly related to tissue K(+) deficiency. Tissue K(+) deficiency increases more when the K(+) intake is higher and K(+) loss increases more with higher than lower tissue K(+) deficiency indicating that, during HK, tissue K(+) deficiency is due to the inability of the body to use K(+) but not to K(+) shortage in the diet.