Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2002-5-14
pubmed:abstractText
Activation of peripheral cannabinoid CB(1) receptors contributes to hemorrhagic hypotension, and endocannabinoids produced by macrophages and platelets may be mediators of this effect. A number of studies have provided evidence that functional links exist in the mechanisms of action of cannabinoids and opioid peptides; and opioids too play an important role in the pathophysiology of hemorrhagic hypotension and shock. On the other hand, melanocortin peptides, which are the main endogenous functional antagonists of opioid peptides, have an antishock effect in animals and humans. Thus, we investigated whether an interaction exists between endocannabinoids and the endogenous opioid/antiopioid system also in a condition of hemorrhagic shock and, particularly, whether the blockade of cannabinoid CB(1) receptors potentiates the antishock effect of melanocortins. Urethane-anesthetized rats were stepwise bled until mean arterial pressure decreased to, and stabilized at, 21-23 mm Hg. In this model of hemorrhagic shock, which caused the death of all control rats within 30 min after vehicle (tween 80, 5% in saline) injection, the intravenous (i.v.) bolus injection of the cannabinoid CB(1) receptor antagonist N-piperidino-5-[4-chlorophenyl]-1-[2,4 dichlorophenyl]-4-methyl-3-pyrazolecarboxamide (SR141716A) increased mean arterial pressure, pulse pressure, respiratory rate and survival rate in a dose-related manner (0.1-3 mg/kg), an almost complete recovery of mean arterial pressure, pulse pressure and respiratory rate, and 100% survival at the end of the observation period (2 h), occurring with the dose of 3 mg/kg. The melanocortin ACTH-(1-24) (adrenocorticotropin) also produced in a dose-related manner (0.02-0.16 mg/kg i.v.) a restoration of cardiovascular and respiratory functions, and increased survival rate, an almost complete recovery and 100% survival at the end of the observation period (2 h) occurring with the dose of 0.16 mg/kg. When a subactive dose of SR141716A (0.2 mg/kg; 30% survival) was associated with a subactive dose of ACTH-(1-24) (0.02 mg/kg; 12% survival), a complete reversal of the shock condition was obtained with 100% survival at the end of the 2-h observation period. The present results show that the concurrent inhibition of both endogenous opioid and cannabinoid systems produces a reversal of hemorrhagic shock more effective than that produced by the inhibition of either of them. These data suggest that functional interactions between endocannabinoids and opioid/antiopioid are at work also in the pathophysiology of hemorrhagic shock.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0014-2999
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
441
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
91-7
pubmed:dateRevised
2007-10-17
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Cannabinoid CB(1) receptor blockade enhances the protective effect of melanocortins in hemorrhagic shock in the rat.
pubmed:affiliation
Section of Pharmacology, Department of Biomedical Sciences, University of Modena and Reggio Emilia, via G. Campi 287, 41100 Modena, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't