Pawinee PiyachaturawatSuparporn MuchimapuraSamaisukh SophasanSurawat JariyawatChumpol PholpramoolJutamaad SatayavivadHitoshi EndouMahidol UniversityKyorin University2018-09-072018-09-071999-04-26Clinical and Experimental Pharmacology and Physiology. Vol.26, No.4 (1999), 323-329030518702-s2.0-0032945463https://repository.li.mahidol.ac.th/handle/20.500.14594/253441. Alterations in skeletal muscle function of chronically K+-depleted male and female rats were investigated in isolated soleus muscles. 2. By 16 weeks K+ deficiency, plasma K+ concentrations in both male and female rats were reduced to approximately 2 mEq/L, which was accompanied by an approximate 50% reduction in muscle K+ content and a marked increase in muscle Na+ content. These changes were similar in both males and females. 3. Plasma creatine phosphokinase activity progressively increased with time in K+-depleted male rats, whereas only a slight increase was observed in female rats. 4. Maximum isometric twitch tension (Pt) and tetanic tension (Po) of K+-depleted soleus muscles from male rats was markedly suppressed; this was not seen for soleus muscles obtained from female rats. 5. After exposure to insulin in low-K+ solution, the contractile tension of soleus from the K+- depleted male rats was suppressed to a greater extent. 6. All alterations in muscle function during chronic K+ depletion were restored to normal after 2 weeks K+ repletion. 7. The results suggest that there is a preponderance for male over female rats in developing alterations in skeletal muscle function during chronic K+ deficiency. The changes may be associated with abnormalities of muscle membrane permeability and cellular function.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyMedicinePharmacology, Toxicology and PharmaceuticsArticleSCOPUS10.1046/j.1440-1681.1999.03036.x