Stimulation of the Potassium Transport System in Low Potassium Type Sheep Red Cells by a Specific Antigen Antibody Reaction

Abstract

SOME sheep have high concentrations of potassium in their red blood cells (HK type) and some have low concentrations (LK type)¹. The gene for LK (Ka^L) is dominant to that for HK (ka^h). Rasmusen and Hall^2,3 reported an association between potassium type and an antigen (M) on the red cells of adult sheep. All HK type but only some LK type red cells were M-positive, that is, they were haemolysed by the isoantibody anti-M. They suggested that genes controlling potassium concentrations also controlled the M antigen, sheep homozygous for M (MM) being HK type (ka^hka^h), and sheep homozygous for m (mm) that is M-negative, being homozygous for the gene for LK (ka^Lka^L). The heterozygous LK sheep (ka^Lka^h) were also heterozygous for M (Mm). The red cells of all newborn lambs contain more potassium than those of adult HK type sheep^4,5, and in those lambs which carry the gene for M, the cells do not react fully with anti-M until adult potassium concentrations are reached^6,7. The conclusion was that the presence of M antigen per se was not essential for the maintenance of a high intracellular content of potassium, and it was suggested that if the hypothetical m factor could be identified, it might prove to be directly involved in active potassium transport. The work reported here sets out to test this hypothesis.