title: Changes from high potassium (hk) to low potassium (lk) in bovine red cells.
abstract: Red cells of newborn calves contain 105-110 mmole K(+) and 1-5 mmole Na(+) per liter of cells. As the animals age the K(+) content decreases to a value of 25-30 mmole/liter of cells after about 60 days. At approximately the same time, the sodium content reaches a value of 60-70 mmole/liter. The time required for half change (t((1/2))) is 35-37 days for both Na(+) and K(+). The activity of (Na + K)-adenosine triphosphatase (ATPase) and the influx of K(42) and Rb(86) into the red cells are high at birth and are reduced to 5 and 15% of their original values, respectively, in mature animals. t((1/2)) for both is of the order of 30-35 days. The membrane Mg-ATPase activity is also high at birth and is reduced with a t((1/2)) of 28-32 days to a final value of about 20% of its activity at birth. Separation of red cells according to their age showed that, in animals at the age of transition, newly formed red cells contain a higher K/Na ratio and a higher active transport capacity than older red cells of the same animal. It is suggested that the changes observed are a reflection of the average age of the red cell population as the animal grows.
mesh_terms: D000251:Adenosine Triphosphatases / Q000097:blood; D000818:Animals; D001693:Biological Transport, Active; D002417:Cattle / Q000502:physiology*; D002462:Cell Membrane / Q000201:enzymology; D002499:Centrifugation, Density Gradient; D004912:Erythrocytes / Q000032:analysis* / Q000201:enzymology / Q000378:metabolism; D005260:Female; D005319:Fetal Hemoglobin / Q000096:biosynthesis; D006207:Half-Life; D006454:Hemoglobins / Q000096:biosynthesis; D066298:In Vitro Techniques; D008297:Male; D010455:Peptides / Q000097:blood; D010743:Phospholipids / Q000097:blood; D011188:Potassium / Q000097:blood* / Q000378:metabolism; D011194:Potassium Isotopes; D012156:Reticulocytes; D012413:Rubidium / Q000378:metabolism; D012964:Sodium / Q000097:blood
chemical_list: D006454:Hemoglobins; D010455:Peptides; D010743:Phospholipids; D011194:Potassium Isotopes; D005319:Fetal Hemoglobin; D012964:Sodium; D000251:Adenosine Triphosphatases; D012413:Rubidium; D011188:Potassium