Related Experiment Videos
Morphine-induced alterations in plasma and tissue cholesterol levels
Life Sciences
|August 3, 1987
Summary
Morphine administration in rats increased harmful cholesterol levels, including low-density lipoprotein (LDL) and very-low-density lipoprotein (VLDL), and decreased protective high-density lipoprotein (HDL). Naltrexone prevented these adverse effects on cholesterol metabolism.
Area of Science:
- Pharmacology
- Cardiovascular Science
- Metabolic Research
Background:
- Opiates, like morphine, are widely used for pain management.
- Dyslipidemia, characterized by abnormal blood lipid levels, is a significant risk factor for cardiovascular disease.
- The impact of chronic opiate administration on lipid profiles and atherosclerosis remains incompletely understood.
Purpose of the Study:
- To investigate the effects of chronic morphine administration on lipid metabolism and aortic cholesterol deposition in rats.
- To determine if naltrexone, an opioid antagonist, can prevent morphine-induced alterations in cholesterol levels.
- To assess whether observed changes are linked to hyperphagia or liver toxicity.
Main Methods:
- Rats were fed either a standard diet or a cholesterol-cholic acid supplemented diet.
- Morphine pellets (75 mg) were implanted to provide sustained drug delivery.
- Plasma lipid profiles (total cholesterol, LDL+VLDL, HDL) and aortic cholesterol content were measured.
- Naltrexone (1.0 mg/kg, sc) was administered daily to a subset of morphine-treated rats.
Main Results:
- Morphine pellet implantation significantly elevated total plasma cholesterol and LDL+VLDL cholesterol while lowering HDL cholesterol in rats on a supplemented diet.
- Atherogenic index increased, correlating with enhanced aortic cholesterol deposition.
- These dyslipidemic effects and aortic changes were abolished by naltrexone treatment.
- Morphine also increased total and LDL+VLDL cholesterol in rats on a normal diet, independent of hyperphagia or hepatotoxicity.
Conclusions:
- Chronic morphine administration induces hypercholesterolemia and promotes aortic cholesterol accumulation in rats.
- Opioid antagonism with naltrexone effectively mitigates these adverse metabolic effects.
- The findings suggest a direct role of opiate action in dyslipidemia, with potential implications for cardiovascular risk in patients using opioid analgesics.