Regulation of cAMP phosphodiesterases by cyclic nucleotides in rat parotid gland.
Approximately 88% of the total cAMP phosphodiesterase (PDE) activity was detected in the supernatant fraction of the rat parotid homogenate. Mono Q ion-exchange chromatography revealed five main peaks (PDE I, PDE II, PDE III, PDE IV and unknown). A high concentration of cGMP (> 1 microM) was necessary to activate PDE II, whereas PDE III was inhibited by cGMP at a concentration that was 1,000 times lower (100 pM). PDEs III and IV were activated by treatment with a catalytic subunit of cAMP-dependent protein kinase (A kinase), and H-8, a A kinase inhibitor, inhibited the activation. Treatment of parotid slices with 1 microM isoproterenol stimulated PDE activity by approximately 120%, and 10 microM propranolol inhibited the activation.
Imai
A
A
Department of Oral Biochemistry, Nippon Dental University, Niigata, Japan.
Nashida
T
T
Shimomura
H
H
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000378:metabolism*; D000818:Animals; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D006868:Hydrolysis; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D009712:Nucleotides, Cyclic / Q000502:physiology*; D010306:Parotid Gland / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D017208:Rats, Wistar
D009712:Nucleotides, Cyclic; D017868:Cyclic AMP-Dependent Protein Kinases; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D007545:Isoproterenol