Membrane-bound Phosphodiesterases in Rat Myocardium
| Autor: | Jorma J. Ohisalo, Allen Kaasik |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Inotrope
Siguazodan Blotting Western Pharmaceutical Science In Vitro Techniques 030204 cardiovascular system & hematology Biology Isozyme 03 medical and health sciences 0302 clinical medicine Western blot medicine Animals Rolipram 030304 developmental biology Pharmacology 0303 health sciences medicine.diagnostic_test Phosphoric Diester Hydrolases Myocardium Cell Membrane Phosphodiesterase Chromatography Ion Exchange Precipitin Tests Rats Isoenzymes Kinetics Biochemistry 3' 5'-Cyclic-AMP Phosphodiesterases biology.protein Indicators and Reagents Rat myocardium Antibody medicine.drug |
| Zdroj: | Journal of Pharmacy and Pharmacology. 48:962-964 |
| ISSN: | 2042-7158 0022-3573 |
| DOI: | 10.1111/j.2042-7158.1996.tb06012.x |
| Popis: | Isoenzyme-specific phosphodiesterase (PDE) inhibitors are potential positive inotropic drugs. For evaluating such drugs in experimental models and to understand the physiological roles of the different isoenzymes, it is necessary to know what isoenzymes are present in the tissues studied. Rat myocardium has been reported to be devoid of the particulate cGMP-inhibited cAMP-PDE (type III isoenzyme). Here we re-evaluate the isoenzyme profile of rat myocardium. The cAMP-PDE isoenzyme patterns were studied by ion-exchange chromatography using siguazodan and rolipram, specific inhibitors of type III and IV isoenzymes, respectively. In contrast to earlier reports, type III isoenzyme was abundant in the particulate fraction. PDE III-specific antibodies depressed PDE activity and stained bands in Western blot with molecular masses 64 and 71 kDa. Type III isoenzyme of myocardial membranes was found to be unstable at 37°C which may explain why earlier investigators have failed to demonstrate its presence. The data presented in this paper show that rat heart particulate fraction contains two low Km PDE isoenzymes, type III and type IV, in equal activities. Thus, in contrast to previous reports, this paper clearly shows the presence of considerable amounts of membrane-bound type III PDE isoenzyme in rat myocardium. |
| Databáze: | OpenAIRE |
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