HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Lant, A. F. Articles by Whittam, R. Search for Related Content PubMed PubMed Citation Articles by Lant, A. F. Articles by Whittam, R.

1. The ionic composition of human red cell ghosts and suspending Ringer solutions have been varied independently. Measurements were made of the incorporation of [³²P]o-phosphate (³²P_i) into ATP associated with different concentration gradients of Na and K across the membrane.

2. Some incorporation of ³²P_i was always found irrespective of the ionic composition of ghosts or media. However, additional labelling of energy-rich phosphate occurred when low Na, high K ghosts were incubated in a high Na, K-free medium. This did not occur when there was only a gradient of either Na or K. Downhill movements of both Na into and K out of the ghosts were needed for the extra labelling.

3. Even in the presence of suitable ionic gradients, the extra incorporation was prevented by ouabain or by adding a small amount of external K sufficient to facilitate normal operation of the Na pump.

4. Increase in internal P_i stimulated the incorporation.

5. The results show that the conditions for forward and backward running of the ATPase system associated with the Na pump are such that both reactions cannot proceed optimally at the same time.