Muscle Potassium and Potassium Losses During Hypokinesia in Healthy Subjects

Abstract

Hypokinesia (HK) induces electrolyte losses in electrolyte-deficient tissue, yet the mechanisms of electrolyte losses in electrolyte-deficient tissue remain unknown. Mechanisms of electrolyte deposition could be involved. To determine the effect of prolonged HK on potassium (K+) deposition were measured muscle K+ content and K+ losses. Studies were conducted on 20 physically healthy male volunteers during 30 days pre-experimental period and 364 days experimental period. Subjects were equally divided into two groups: control subjects (CS) and experimental subjects (ES). The CS group was run average distances of 9.8±1.7 km day(-1) and the ES group was walked average distances of 2.7±0.6 km day(-1). Muscle K+ content decreased (p<0.05) and plasma K+ concentration, and K+ losses in urine and feces increased (p<0.05) in the ES group compared to their pre-experimental level and the values in their respective CS group. Muscle K+ content, plasma K+ level, and urine and fecal K+ losses did not show any changes in the CS group compared to their pre-experimental values. The conclusion was that K+ losses in K+-deficient muscle of healthy subjects could have been attributable to the less efficient K+ deposition inherently to prolonged HK.

Chronic head‐down‐tilt sleeping as physiological regulator of bone remodelling during diminished muscular activity in humans

“…The decreased total fluid volume is most detrimental to the body because it forces the body, particularly the vital organs, to work much harder than they normally would. Reduction in blood volume results in higher plasma electrolyte which leads to higher losses of electrolytes and electrolyte deficiency (Krotov, 1982;Volozhin, 1987;Zorbas et al, 1988aZorbas et al, , 1994Zorbas et al, , 1998Zorbas et al, , 2002aZorbas et al, , 2002bDeogenov et al, 2010;Federenko et al, 2010). To counteract these consequences, different preventive measures have been used which did not have significant benefits (Zorbas & Medvedev, 1986, 1987aZorbas et al, 1987bZorbas et al, , 1987cZorbas et al, , 1990Zorbas et al, , 1993aZorbas et al, , 1993b.…”

Non-Selective PDE4 Inhibition Induces a Rapid and Transient Decrease of Serum Potassium in Mice

“…In humans, as well as in experimental animals, hypothermia is frequently associated with hypokalemia due to an increased transcellular shift of serum potassium into cells [ 41 , 42 , 43 , 44 ]. Moreover, as muscle contractions cause a release of potassium from myocytes, differences in the animals’ motility may also affect serum potassium levels [ 45 , 46 , 47 ]. Thus, we wished to confirm that the observed reduction in serum potassium levels was not simply a consequence of PDE4 inhibitor-induced hypothermia and/or hypokinesia in the animals.…”