The purine nucleotide cycle activity in renal cortex and medulla.
Formation of adenine nucleotides, IMP, malate + fumarate, ammonia, adenosine, and inosine + hypoxanthine + uric acid were measured in cytosolic extracts from renal cortex and medulla. The order of substrate addition was IMP, then 2-deoxyglucose, then P-creatine. Compared with cortex, medulla showed greater rates of formation of adenosine triphosphate (ATP) from P-creatine, of adenosine monophosphate (AMP) from 2-deoxyglucose, and of total adenine nucleotides from IMP. These results suggest that the purine nucleotide cycle is more active in medulla than in cortex. This cycle may provide a mechanism in medulla for storing purine nucleotides which can be used to restore ATP pools in the relatively hypoxic conditions of this part of the kidney.
Stepiński
J
J
Department of Clinical Biochemistry, Medical Academy, Gdańsk, Poland.
Bizon
D
D
Piec
G
G
Angielski
S
S
D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D005650:Fumarates / Q000378:metabolism; D066298:In Vitro Techniques; D007291:Inosine Monophosphate / Q000378:metabolism; D007672:Kidney Cortex / Q000378:metabolism*; D007679:Kidney Medulla / Q000378:metabolism*; D008293:Malates / Q000378:metabolism; D011685:Purine Nucleotides / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D005650:Fumarates; D008293:Malates; D011685:Purine Nucleotides; D007291:Inosine Monophosphate; D001224:Aspartic Acid; D000249:Adenosine Monophosphate; C030298:malic acid; C032005:fumaric acid; D000255:Adenosine Triphosphate