Cardiac intracellular regulation: exercise effects on the cAMP system and A-kinase.
The effects of acute and chronic exercise on 3'5'-adenosine monophosphate (cAMP) concentration, adenylate cyclase activity, cAMP-phosphodiesterase (PDE), and cAMP-dependent protein kinase (A-kinase) activity are reviewed. During very mild- to moderate-intensity exercise with durations of up to 1 h, the cAMP concentration within the myocardium is related to the intensity of exercise. At higher intensities or during very long-duration exercise, this does not seem to be the case. The mode of exercise does not seem to be a significant factor in altering cardiac cAMP concentration. Duration is more important than intensity in determining cAMP-PDE activity. Post-exercise increases in cAMP-PDE are very similar in trained animals, independent of duration and intensity of work. These increases are attenuated and less variable as compared with untrained animals. The activity of A-kinase seems to increase with exercise training. The extent of the increase in A-kinase activity is likely dependent on the duration (and perhaps the intensity) of training and is of greater magnitude than the changes in the other enzymes of the cAMP system.
Dunbar
C C
CC
Department of Physical Education, Brooklyn College, City University of New York, Brooklyn 11210.
Kalinski
M I
MI
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D009206:Myocardium / Q000201:enzymology* / Q000378:metabolism; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D010805:Physical Conditioning, Animal; D005082:Physical Exertion / Q000502:physiology*; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D013997:Time Factors
D011494:Protein Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D010727:Phosphoric Diester Hydrolases; D000262:Adenylyl Cyclases