Effect of age and day time on the adenosine modulation of basal and insulin-stimulated glucose transport in rat adipocytes.
1. The relationship between the activity of adenosine metabolizing enzymes 5'nucleotidase (5'N), adenosine kinase (A.K.) and adenosine deaminase (A.D.) with basal and insulin-stimulated glucose transport in isolated fat cells from young and old animals was studied at 08:00 and 16:00 hr. 2. In cells from young animals a larger insulin-stimulation of glucose transport was observed at 16:00 hr than at 08:00 hr. Also at 16:00 hr small changes in 5'N, A.K. and A.D. activities suggest a decrease in adenosine formation. 3. In the cells from old animals no effect of insulin was observed at any time, while a 3-5-fold increase in 5'N indicated a predominance of adenosine formation at both times studied. 4. An inverse relationship was observed in the changes of adenosine metabolism and insulin action.
Bush
P
P
Departamento de Bioenergética, Universidad Nacional Autónoma de México, D.F. México.
Souness
J E
JE
Chagoya de Sánchez
V
V
D000241:Adenosine / Q000378:metabolism*; D000375:Aging / Q000378:metabolism* / Q000502:physiology; D000818:Animals; D001693:Biological Transport, Active; D002940:Circadian Rhythm; D005947:Glucose / Q000493:pharmacokinetics*; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D007328:Insulin; D005947:Glucose; D000241:Adenosine