Maximal activities of enzymes involved in adenosine metabolism in muscle and adipose tissue of rats under conditions of variations in insulin sensitivity.
The maximal activities of 5'-nucleotidase, adenosine deaminase and adenosine kinase were measured in quadriceps or soleus muscle from animals in which the sensitivity to insulin was changed. Most conditions caused no effect on the activities but exercise-training increased the activity of adenosine deaminase and cold exposure increased the activity of 5'-nucleotidase in soleus muscle: in addition, ageing decreased markedly the activities of all three enzymes in both muscles. When the activities are based on mg protein they are much higher in both white and brown adipose tissue than in muscle, suggesting that changes in adenosine concentration may be important in changing insulin sensitivity in adipose tissue whereas changes in adenosine receptor number may be more important in muscle.
Newsholme
E A
EA
Blomstrand
E
E
Newell
J
J
Pitcher
J
J
D015720:5'-Nucleotidase; D000241:Adenosine / Q000378:metabolism*; D000243:Adenosine Deaminase / Q000378:metabolism; D000248:Adenosine Kinase / Q000378:metabolism; D000273:Adipose Tissue / Q000378:metabolism*; D000315:Adrenalectomy; D000367:Age Factors; D000818:Animals; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D009132:Muscles / Q000378:metabolism*; D009708:Nucleotidases / Q000378:metabolism; D009765:Obesity / Q000378:metabolism; D005082:Physical Exertion; D051381:Rats; D011924:Rats, Zucker
D007328:Insulin; D000248:Adenosine Kinase; D009708:Nucleotidases; D015720:5'-Nucleotidase; D000243:Adenosine Deaminase; D000241:Adenosine