Exercise and the cAMP system in rat adipose tissue II. Nucleotide catabolism.
In this study the effect of exercise training on the adenosine 3',5'-cyclic monophosphate (cAMP) system of rat adipose tissue has been investigated. The basal amount of cAMP for the exercising rats was 0.179 +/- 0.021 nmol/10(6) cells, the same value as for the controls. Phosphodiesterase activities (low and high Km) remained unaffected as a result of the program of treadmill running. Kinetic constants for the low- and high-Km phosphodiesterases revealed that the affinity of the enzymes for substrate (cAMP) was unaltered by physical training. Finally, ethyleneglycol-bis(beta-aminoethylether)-N,N'-tetraacetic acid, possibly through its effect on calmodulin, stimulated or inhibited (depending on concentration) phosphodiesterase activity in the same direction and to a similar extent in extracts of adipose tissue from runners and controls. Taken together, these data clearly demonstrate the exercise training has no effect on the cAMP system of adipose tissue in male rats.
D000273:Adipose Tissue / Q000201:enzymology*; D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D005082:Physical Exertion; D051381:Rats
D000242:Cyclic AMP; D010727:Phosphoric Diester Hydrolases