Adenosine deaminase in stroma-free hemoglobin solution is not responsible for coronary vasoconstriction.
Erythrocytes contain a high concentration of cytosolic adenosine deaminase and this enzyme activity is present in preparations of stroma-free hemoglobin (SFHS). The documented vasoconstrictor activity of SFHS preparations does not appear to be due to interference with endogenous adenosine-mediated mechanisms, because removal of greater than 80% of adenosine deaminase activity failed to affect the vasoconstrictor potency of SFHS preparations. We have also demonstrated the presence of a contractility-depressant activity in SFHS when the latter was added to aqueous buffer perfusing rat Langendorff-hearts. This activity is diminished in phosphocellulose-purified preparations with reduced adenosine deaminase activity but is not necessarily causally related to this enzyme.
Department of Biochemistry, University of Ottawa, Ontario, Canada.
K
K
Lawless
P J
PJ
Anderson
G P
GP
Biro
D000243:Adenosine Deaminase / Q000097:blood* / Q000502:physiology; D000818:Animals; D001794:Blood Pressure; D003331:Coronary Vessels / Q000502:physiology*; D006321:Heart / Q000502:physiology*; D006454:Hemoglobins / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D009700:Nucleoside Deaminases / Q000097:blood*; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains; D014661:Vasoconstriction
D006454:Hemoglobins; D009700:Nucleoside Deaminases; D000243:Adenosine Deaminase