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The Importance of PKC in the
Generation of Ischemic Contracture
in Spontaneously Hypertensive
Rats (Shr): Relationship with the
Postischemic Recovery

Mosca, Susana María; Salas, Margarita Ana;
Cingolani, Horacio Eugenio

Centro de Investigaciones Cardiovasculares, Facultad de
Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina

Our objective was to characterize the role of the protein-kinase (PKC) against ischemic and reperfusion injury in SHR animals. Isolated perfused hearts of SHR and Wistar (W) normotensive rats of equal age were submitted to the following protocols: I) 10 min of stabilization (S); II) 10 min of S and 20 min of global ischemia (Is); III) 10 min of S, 20 min of Is and 30 min of reperfusion and IV) was repeated the protocol III in presence of PKC blocker, chelerythrine (Ch). The ischemic contracture (IC) and the postischemic recovery were assessed through the left ventricular end diastolic pressure (LVEDP) and developed pressure (LVDP), respectively. At the end of I and II protocols PKC-e (the most abundant isoform in rat) localization by immunofluorescence was determined. IC was significantly greater in SHR than in W (LVEDP= 39 ± 4 vs. 27 ± 3 mmHg, p < 0.05). The PKC inhibition diminished IC in SHR but did not modified it in W (LVEDP= 10 ± 4 and 21 ± 7 mmHg in SHR and W, respectively). In control conditions the postischemic recovery was similar in both strains (LVDP= 66 ± 12% in SHR and 61 ± 6 % in W). In presence of Ch the postischemic recovery decreased (LVDP= 26 ± 12% and 35± 8% in SHR and W, respectively). During S, PKC-e staining was observed in intercalated disks and perinuclear zone being its distribution similar in both strains. At the end of ischemia only in SHR PKC-e staining increased in these zones and cytoplasmic distribution was also evident.

The present results show that although PKC activation induced by ischemia improves the postischemic recovery in a similar manner in hypertensive and normotensive animals, IC is exacerbated only in SHR, where PKC-e is detected at level of intercalated disks and cytoplasm.

 

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2nd Virtual Congress of Cardiology

Dr. Florencio Garófalo
Steering Committee
President
Dr. Raúl Bretal
Scientific Committee
President
Dr. Armando Pacher
Technical Committee - CETIFAC
President
fgaro@fac.org.ar
fgaro@satlink.com
rbretal@fac.org.ar
rbretal@netverk.com.ar
apacher@fac.org.ar
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