Effect of ouabain on the breakdown of adenine nucleotides in glucose-depleted nucleated red blood cells. Characterization of ATPase

The present report confirms the presence of Na(+)-K(+)-Mg2+ ATPase in the erythrocyte membranes of the frog Rana balcanica (previously Rana ridibunda) (Schneider et al. 1993; Sofianidou et al. 1994). The Na(+)-K(+)-Mg2+ ATPase activity was 60% reduced by the presence of ouabain. The pH optimum was 8...

Full description

Saved in:

Bibliographic Details
Published in:	General physiology and biophysics Vol. 17; no. 2; pp. 143 - 156
Main Authors:	Kaloyianni, M, Tsikriktsi, O, Tsianopoulou, P
Format:	Journal Article
Language:	English
Published:	Slovakia 01-06-1998
Subjects:	Adenine Nucleotides - blood Adenosine Triphosphate - metabolism Animals Biophysical Phenomena Biophysics Blood Glucose - metabolism Enzyme Inhibitors - pharmacology Erythrocyte Membrane - enzymology Erythrocytes - drug effects Erythrocytes - metabolism Hydrogen-Ion Concentration In Vitro Techniques Kinetics Ouabain - pharmacology Ranidae - blood Sodium-Potassium-Exchanging ATPase - antagonists & inhibitors Sodium-Potassium-Exchanging ATPase - blood
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	The present report confirms the presence of Na(+)-K(+)-Mg2+ ATPase in the erythrocyte membranes of the frog Rana balcanica (previously Rana ridibunda) (Schneider et al. 1993; Sofianidou et al. 1994). The Na(+)-K(+)-Mg2+ ATPase activity was 60% reduced by the presence of ouabain. The pH optimum was 8.0, the optimum Mg2+:ATP concentration ratio was 2.2:1. The existence of an ATPase with a high K(m) for ATP (1.48 mmol/l) was postulated. At pH 7.4 and 8.0, the adenine nucleotide pattern of glucose-depleted erythrocytes showed a characteristic reduction in ATP contents. Adenine nucleotide concentrations were higher at pH 7.4 than at pH 8.0. Ouabain inhibited ATP breakdown at both pH values studied. The strongest inhibition was observed at pH 7.4. The decline of the total contents of adenine nucleotides appears to be determined by the rate of AMP breakdown.
Bibliography:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	0231-5882