In:
Circulation, Ovid Technologies (Wolters Kluwer Health), Vol. 104, No. 6 ( 2001-08-07), p. 705-710
Abstract:
Background — Phosphodiesterase III inhibitors (PDEIII-Is) improve the hemodynamic status of heart failure via inotropic/vasodilatory effects attributable to the increase in intracellular cAMP level. Direct cardioprotection by PDEIII-Is and its underlying mechanisms, however, have not been identified. We tested the infarct size–limiting effect of PDEIII-Is and the roles of cAMP, protein kinase (PK) A, PKC, and mitogen-activated protein kinase (MAPK) families in open-chest dogs. Methods and Results — Milrinone, olprinone (PDEIII-Is), or dibutyryl-cAMP (db-cAMP) was injected intravenously 30 minutes before 90-minute ischemia, followed by 6 hours of reperfusion. Olprinone was also examined with an intracoronary cotreatment with a PKA inhibitor (H89), a PKC inhibitor (GF109203X), an extracellular signal–regulated kinase kinase (MEK) inhibitor (PD98059), or a p38 MAPK inhibitor (SB203580) throughout the preischemic period. Either PDEIII-Is or db-cAMP caused substantial hemodynamic changes, which returned to control levels in 30 minutes. Collateral flow and percent risk area were identical for all groups. Both PDEIII-Is and db-cAMP increased myocardial p38 MAPK activity during the preischemic period, which was blocked by H89, but not by GF109203X. Both PDEIII-Is and db-cAMP reduced infarct size (19.1±4.1%, 17.5±3.3%, and 20.3±4.8%, respectively, versus 36.1±6.2% control, P 〈 0.05 each). Furthermore, the effect of olprinone was blunted by either H89 (35.5±6.4%) or SB203580 (32.6±5.9%), but not by GF109203X or PD98059. H89, GF109203X, PD98059, or SB203580 alone did not influence infarct size. Conclusions — Pretreatment with PDEIII-Is has cardioprotective effects via cAMP-, PKA-, and p38 MAPK–dependent but PKC-independent mechanisms in canine hearts.
Type of Medium:
Online Resource
ISSN:
0009-7322
,
1524-4539
DOI:
10.1161/hc3201.092216
Language:
English
Publisher:
Ovid Technologies (Wolters Kluwer Health)
Publication Date:
2001
detail.hit.zdb_id:
1466401-X
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