Mazenot C, Gobeil F, Ribuot C, Regoli D, Godin-Ribuot D. Delayed myocardial protection induced by endotoxin does not involve kinin B(1)-receptors.
Br J Pharmacol 2000;
131:740-4. [PMID:
11030723 PMCID:
PMC1572378 DOI:
10.1038/sj.bjp.0703619]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Endotoxin is known to confer a delayed protection against myocardial infarction. Lipopolysaccharide (LPS) treatment also induces the de novo synthesis of kinin B(1)-receptors that are not present in normal conditions. The aim of this study was to evaluate whether LPS-induced B(1)-receptors are implicated in the reduction of infarct size brought about by LPS. Rabbits were submitted to a 30-min coronary artery occlusion and 3-h reperfusion sequence. Six groups were studied: pretreated or not (control animals) with LPS (5 microgram kg(-1) i.v.) 24 h earlier and treated 15 min before and throughout ischaemia - reperfusion with either the B(1)-antagonist R-715 (1 mg kg(-1) h(-1)), the B(1)-agonist Sar-[D-Phe(8)]-des-Arg(9)-bradykinin (15 microgram kg(-1) h(-1)) or vehicle (saline). Infarct size and area at risk were assessed by differential staining and planimetric analysis. The presence of B(1)-receptors in LPS-pretreated animals was confirmed by a decrease in mean arterial pressure in response to B(1) stimulation. LPS-pretreatment significantly reduced infarct size (6.4+/-1.7%, of area at risk vs 24.1+/-2.5% in control animals, P<0.05). This protection was not modified by B(1)-receptor antagonism (7.4+/-2.2%, NS) or stimulation (5.2+/-1.2%, NS). Neither antagonist nor agonist modified infarct size in control animals. In conclusion, these data suggest that LPS-induced myocardial protection in the rabbit is not related to concomitant de novo B(1)-receptor induction.
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