Synthesis of adenosine triphosphate at the expense of downhill cation movements in intact human red cells - PubMed (original) (raw)

Synthesis of adenosine triphosphate at the expense of downhill cation movements in intact human red cells

I M Glynn et al. J Physiol. 1970 Apr.

Abstract

1. When red cells that have been starved for about 6 hr are loaded with inorganic phosphate and incubated in high-sodium potassium-free media, the ouabain-sensitive efflux of potassium from the cells is accompanied by a ouabain-sensitive incorporation of inorganic phosphate into ATP.2. The magnitude of the incorporation varies roughly linearly with the concentration of sodium in the medium. The ratio (ouabain-sensitive potassium efflux)/(ouabain-sensitive ATP synthesis) is probably not much less than 2 nor much greater than 3.3. Potassium in the medium inhibits the ouabain-sensitive incorporation of phosphate. The concentration of potassium necessary for half-maximal inhibition is about the same as the concentration at which, under similar conditions, ouabain-sensitive potassium influx and the stimulation of ouabain-sensitive potassium efflux are both half-maximal.4. These observations suggest that the ouabain-sensitive efflux of potassium from red cells incubated in high-sodium potassium-free media is associated with a reversal of the entire pump cycle. In media containing sufficient potassium to saturate the pump, the efflux appears to involve the reversal of only part of the cycle.

PubMed Disclaimer

Similar articles

Cited by

References

    1. J Physiol. 1967 Sep;192(1):237-56 - PubMed
    1. Lancet. 1958 Apr 12;1(7024):766-9 - PubMed
    1. J Physiol. 1970 Apr;207(2):371-91 - PubMed
    1. J Gen Physiol. 1969 Jul 1;54(1):289-305 - PubMed
    1. Biochem J. 1951 Aug;49(3):286-92 - PubMed

MeSH terms

Substances

LinkOut - more resources