title: Diurnal variation of erythrocyte sodium-lithium countertransport rate and intracellular cation concentrations.
abstract: Differences in erythrocyte sodium-lithium countertransport rate and erythrocyte potassium concentration were found between 0900 h and 2100 h in ten healthy individuals. Sodium-lithium countertransport rates were lowest at 0900 h (x: 0.34 mmol/l per h; SD: 0.15) and highest at 1200 h (x: 0.42 mmol/l per h; SD: 0.16). Erythrocyte potassium concentrations increased progressively during the day, while erythrocyte sodium concentrations did not change significantly during the day. For comparative and epidemiological studies of erythrocyte sodium-lithium countertransport rate blood samples should be taken at the same time of the day.
authors.affiliation: Department of Medicine, Wellington School of Medicine, New Zealand.
authors.forename: R W
authors.initials: RW
authors.lastname: Siebers
authors.forename: T J
authors.initials: TJ
authors.lastname: Maling
mesh_terms: D017920:Antiporters; D001826:Body Fluids / Q000378:metabolism*; D002352:Carrier Proteins / Q000097:blood*; D002940:Circadian Rhythm / Q000502:physiology*; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007424:Intracellular Fluid / Q000378:metabolism*; D008297:Male; D011188:Potassium / Q000097:blood
chemical_list: D017920:Antiporters; D002352:Carrier Proteins; C045885:sodium-lithium countertransporter; D011188:Potassium; D006854:Hydrocortisone