Abstract
The distinct phosphodiesterase isoenzyme activities in guinea-pig lung were identified and characterised. We demonstrate that protein kinase A catalyses the activation of lung Type V cyclic GMP phosphodiesterase. This occurs via a marked change in the Vmax for cyclic GMP hydrolysis. The sensitivity of the activated PDE to inhibition by zaprinast is also markedly reduced (zaprinast inhibits in PDE activity via a mixed mechanism). We suggest that activation of the PDE by protein kinase A involves a mechanism that leads to alteration in the regulatory action of a non-catalytic cyclic GMP binding site.
Original language | English |
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Pages (from-to) | 35-49 |
Number of pages | 15 |
Journal | Agents and actions. Supplements |
Volume | 43 |
Publication status | Published - 1993 |
Keywords
- 3',5'-Cyclic-GMP Phosphodiesterases
- animals
- catalysis
- enzyme activation
- Guinea Pigs
- isoenzymes
- lung
- muscle
- perfusion
- phosphoric diester hydrolases
- purinones
- pyrazines