Abstract | BACKGROUND: MATERIALS AND METHODS: Using the rabbit Langendorff model, the functional recovery of control hearts (following 2 h of global ischemia) was compared to hearts pretreated with delta antagonist NTB (1 microM) or kappa antagonist, nor-BNI (1 microM). Measures included percentage of return of isovolumetric developed pressure (LVDP), myocardial oxygen consumption (MVO(2)) and coronary flow (CF). In additional studies, untreated hearts were harvested at baseline, following ischemia, or following 5 or 45 min of reflow. Tissue concentrations of met-enkephalin and dynorphin B were measured by RIA. RESULTS: After 45 min of reflow, hearts pretreated with either NTB or nor-BNI showed impaired functional recovery by a decrease in LVDP (P < 0.05); however, MVO(2) or CF were unaffected. RIA data shows that baseline levels of both peptides are similar and increase significantly during ischemia, but reflow dynorphin levels drop far below baseline, while met-enkephalin returns to baseline. CONCLUSION: Antagonism of both delta and kappa opioid receptor subtypes equally contributes to impaired left ventricular function, independent of altered perfusion or metabolic rate. Endogenous kappa-receptor agonists may contribute primarily during ischemia or early reflow, since low late reflow dynorphin content did not correlate with altered functional recovery.
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Authors | Matthew A Romano, Elisabeth M Seymour, Jennifer A Berry, Robert A McNish, Steven F Bolling |
Journal | The Journal of surgical research
(J Surg Res)
Vol. 118
Issue 1
Pg. 32-7
(May 01 2004)
ISSN: 0022-4804 [Print] United States |
PMID | 15093714
(Publication Type: Journal Article)
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Chemical References |
- Endorphins
- Narcotic Antagonists
- Receptors, Opioid, delta
- Receptors, Opioid, kappa
- norbinaltorphimine
- Enkephalin, Methionine
- Naltrexone
- Dynorphins
- rimorphin
- naltrindole
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Topics |
- Animals
- Dynorphins
(metabolism)
- Endorphins
(metabolism)
- Enkephalin, Methionine
(metabolism)
- In Vitro Techniques
- Ischemic Preconditioning, Myocardial
- Naltrexone
(analogs & derivatives, pharmacology)
- Narcotic Antagonists
(pharmacology)
- Rabbits
- Receptors, Opioid, delta
(antagonists & inhibitors)
- Receptors, Opioid, kappa
(antagonists & inhibitors)
- Recovery of Function
- Ventricular Function, Left
(drug effects)
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