ELECTROLYTE METABOLIC CHANGES IN RATS DURING AND AFTER EXPOSURE TO HYPOKINESIA

The objective of this study was to determine fluid-electrolyte changes in male Wistar rats during 90 days of hypokinesia (decreased motor ac tivity) and 15 days posthypokinesia. The animals were divided into two groups: rats subjected to hypokinesia served as experimental animals and rats placed under vivarium conditions served as control animals. T he hypokinetic effect was carried out by keeping the experimental rats in small individual cages which restricted all their movements withou t hindering food and water intake. Determination was made of body weig ht, fluid consumed and eliminated in urine, sodium and potassium excre tion in urine, concentrations of sodium and potassium in urine, the he matocrit level and water content in blood, and plasma concentration of sodium and potassium. During the experimental period body weight, wat er intake, urinary sodium and potassium content, and water content in blood decreased significantly, while electrolyte excretion in urine, p lasma electrolyte concentration, hematocrit content and fluid excretio n in urine increased significantly in the hypokinetic animals when com pared with the control animals. During the initial seven days of the p ostexperimental period, water intake increased significantly while hem atocrit level, water content in blood, and electrolye plasma concentra tion remained markedly higher, and the fluid electrolyte excretion and electrolyte concentration thereof in urine decreased significantly. H owever, all these changes reverted back to the control level by the en d of the post-experimental period. It was concluded that prolonged hyp okinesia (HK) and the initial stages of post hypokinesia are associate d with significant sodium and potassium changes and water consumption and elimination disturbances.