THE EFFECT OF LITHIUM TREATMENT ON ERYTHROCYTE MEMBRANE ATPase ACTIVITIES AND ERYTHROCYTE ION CONTENT

Abstract

ATPase activities were studied in erythrocyte membranes prepared from blood of patients suffering from affective disorders. Long‐term (9–12 months) administration of lithium led to an increase in the erythrocyte membrane Na/K ATPase activity (54%) when studied on an age and sex matched basis or when the patients were studied before and after treatment. The Mg ATPase activity was also increased (38%) but there was no consistent effect of lithium treatment on Ca stimulated ATPase activity in the membranes. It is suggested that the effect of lithium treatment on Na/K ATPase was due to recovery of the patients rather than an effect of the drug. MgATPase activity increased regardless of clinical condition. Short‐term lithium treatment (2–4 weeks) led to increased Mg ATPase activity (43%). These results suggest that lithium treatment itself causes an increase in Mg ATPase activity and that this effect is not dependent on changes in protein synthesis. Lithium treatment (long‐term) increased the erythrocyte sodium content by 15%. No effect on plasma sodium, magnesium, potassium or erythrocyte magnesium and potassium was observed.

Correlation between cyanide-induced decreases in ocular Ca²⁺-ATPase and lenticular opacification

“…15 The assay mixture contained 0.1ml of 1mm EDTA; 0.4ml of 30mM MgCl 2 ; 0.4ml of 5mm CaCl 2 ; 0.3ml of 160mM tris buffer, pH 7.4 and 0.4ml of 0.3mM disodium ATP. Reaction was started by the addition of 0.4ml tissue homogenate.…”

Combined arsenic and di-(2-ethylhexyl) phthalate exposure elicits responses in brain ATPases different from hepatic and renal activities in rats

“…The assay of the Na + /K + -ATPase activities followed the procedure of Hesketh et al (1978) and the inorganic phosphate Tris-HCl (pH 7.4), and 8.0 mM ATP-Na2. The reaction was initiated with the addition of 0.2 ml of tissue homogenate and the mixture incubated at 37°C for 1 h. The reaction was terminated by adding 0.8 ml of ice-cold 10% (w/v) trichloroacetic acid and the resultant mixture was allowed to stand for 20 min at 4°C before it was centrifuged at 4,000 g for 5 min.…”

Respiratory Surveillance and Ca²⁺-ATPase Enzyme Activity Studies of <i>Clarias gariepinus </i>Exposed to Acute Toxicity of Cyanide

“…The homogenate was then transferred into a vial and preserved in a refrigerator at 4 O C. All tissue extracts were analysed within 24 hours. Ca 2+ -ATPase activity was measured by estimating the amount of inorganic phosphate liberated following incubation of aliquots of tissue homogenate with disodium ATP (Heskett et al, 1978). The assay mixture contained 0.1ml of 1mm EDTA; 0.4ml of 30mM MgCl 2 ; 0.4ml of 5mm CaCl 2 ; 0.3ml of 160mM tris buffer, pH 7.4 and 0.4ml of 0.3mM disodium ATP.…”