Early and delayed protection by capsaicin against reperfusion injury in rat hearts.
OBJECTIVE
To study early or delayed cardioprotection afforded by pretreatment with capsaicin.


METHODS
The isolated rat heart was perfused in a Langendorff model. Heart rate, coronary flow, left ventricular pressure, and its first derivative (+/- dp/dtmax) were recorded, and the calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) and the release of creatine kinase (CK) were measured.


RESULTS
Capsaicin (50 mg.kg-1, s.c.) improved the recovery of cardiac function and decreased the release of CK. CK was (2.12 +/- 0.40) and (0.26 +/- 0.04) u.min-1.g-1(wet wt) for ischemia-reperfusion (I/R) and capsaicin + I/R, respectively (P < 0.05). Capsaicin treatment caused an increase in the concentration of CGRP-LI in plasma. CGRP-LI was (135 +/- 12) and (304 +/- 45) ng.L-1 for vehicle + I/R and capsaicin + I/R, respectively (P < 0.05). After pretreatment with capsaicin to deplete the sensory nerve transmitter content, the cardioprotection and the increased level of CGRP by capsaicin were abolished. A delayed protection was shown in the hearts obtained from the rats pretreated with capsaicin 24 h or 48 h before the experiments.


CONCLUSIONS
Pretreatment with capsaicin induces the early and delayed cardioprotection, which may be related to stimulation of CGRP release in the rat.
Department of Pharmacology, Hunan Medical University, Changsha 410078, China.
F W
FW
Zhou
Y J
YJ
Li
H W
HW
Deng
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000097:blood; D002211:Capsaicin / Q000494:pharmacology*; D003402:Creatine Kinase / Q000097:blood; D006334:Heart Function Tests; D066298:In Vitro Techniques; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D003402:Creatine Kinase; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin