Effect of chronic lithium chloride on membrane adenosine triphosphatases in certain postural muscles of rats

• Published in: European journal of pharmacology Vol. 259; no. 1; pp. 7 - 13
• Main Authors: Adipudi, Vijayalakshmi, Reddy, V.Krishna
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 23.06.1994; Elsevier
• Subjects: Adenosine Triphosphatases - metabolism; Animals; ATPase; Biological and medical sciences; Ca(2+) Mg(2+)-ATPase - metabolism; Calcium - metabolism; Calcium-Transporting ATPases - metabolism; Cell Membrane - enzymology; chronic; Extensor digitorum longus; Li; Lithium Chloride - pharmacology; Male; Medical sciences; Miscellaneous; Mitochondria, Muscle - enzymology; Muscles - enzymology; Neuropharmacology; Pharmacology. Drug treatments; Plantaris; Rats; Rats, Wistar; Sodium-Potassium-Exchanging ATPase - metabolism; Soleus; Soleus; Extensor digitorum longus; Plantaris; Li; chronic; ATPase; Rat; Enzyme; Rodentia; Adenosinetriphosphatase; Electrophysiology; Lithium; Striated muscle; Long term; Biological activity; Posture; Vertebrata; Mammalia; Animal; Hydrolases; Antipsychotic; Mechanism of action; ATP
• ISSN: 0014-2999; 1879-0712
• DOI: 10.1016/0014-2999(94)90150-3

Lithium has been extensively used as an antidepressant in the treatment of manic depressive disorders requiring chronic administration. Here, we report a study of the effect of long-term lithium treatment on the activities of membrane adenosine triphosphatases (ATPases) in certain postural muscles of rat. Specifically, Ca 2+-ATPase, Na +,K +-ATPase and Mg 2+-ATPase activities were measured in the soleus, extensor digitorum longus and plantaris muscles following 6 weeks of treatment with LiCl. Increases were observed in the Na +,K +-ATPase activity whereas the Mg 2+-ATPase activity decreased with prolonged LiCl treatment. The most pronounced effect was a highly significant ( P<0.001) increase in the mitochondrial Ca 2+-ATPase and Na +,K +-ATPase activity to almost 50–100% above the control. The increases in the mitochondrial Ca 2+-ATPase activity of extensor digitorum longus and plantaris were 70% and 100%, respectively. The corresponding increases in the Na +,K +-ATPase activity were 127%, 99% and 87% for soleus, extensor digitorum longus and plantaris, respectively. Irrespective of the differences in the fiber pattern and physiological function, all three muscles responded in a similar way to Li +. The changes in the membrane ATPases reflect a deranged ATP turnover, thus affecting the overall energy state of the animal. Based on these results, we hypothesize that Li + produces its effects by interfering with cation transport processes. Since Li + affects the neural excitability of the cell it is suggested that the stimulation of the ATPases may be important in the psychotropic properties of the ion.