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Hypertensive state, independent of hypertrophy, exhibits an attenuated decrease in systolic function on cardiac
Craig Bolte1, Gilbert Newman, Jo El J Schultz
1Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.
American Journal of Physiology. Heart and Circulatory Physiology
|February 3, 2009
Summary
Hypertension alters the body's opioid system, affecting heart function. This study found changes in beta-endorphin levels and reduced cardiac response to kappa-opioid agonists in hypertensive hamsters.
Area of Science:
- Cardiovascular Physiology
- Neuroendocrinology
- Pharmacology
Background:
- Opioids are used to manage symptoms in advanced heart failure.
- The impact of cardiac disease on the myocardial opioidergic system requires investigation.
Purpose of the Study:
- To evaluate the effect of prolonged hypertension on myocardial opioidergic activity.
- To determine how hypertension alters cardiac response to opioid receptor agonists.
Main Methods:
- Utilized a hamster model of spontaneous hypertension at pre-hypertensive and hypertensive stages.
- Assessed plasma and cardiac opioid peptide levels (beta-endorphin, dynorphin A, enkephalins).
- Examined cardiac function response to selective opioid receptor agonists (kappa, delta, mu) in ex vivo working hearts.
Main Results:
- Plasma beta-endorphin was decreased in both pre-hypertensive and hypertensive states.
- No changes in cardiac beta-endorphin, dynorphin A, or enkephalins were detected.
- Kappa- and delta-opioid receptor agonists decreased cardiac function; this effect was attenuated in hypertensive hearts.
Conclusions:
- Hypertension is associated with altered peripheral and myocardial opioid expression and signaling.
- The opioidergic system's modulation of cardiac function is impaired in hypertension.
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