title: Opioid receptor agonists may favorably affect bone mechanical properties in rats with estrogen deficiency-induced osteoporosis.
abstract: The results of epidemiological, clinical, and in vivo and in vitro experimental studies on the effect of opioid analgesics on bone are inconsistent. The aim of the present study was to investigate the effect of morphine (an agonist of opioid receptors), buprenorphine (a partial μ opioid receptor agonist and κ opioid receptor antagonist), and naloxone (an antagonist of opioid receptors) on the skeletal system of female rats in vivo. The experiments were carried out on 3-month-old Wistar rats, divided into two groups: nonovariectomized (intact; NOVX) rats and ovariectomized (OVX) rats. The bilateral ovariectomy was performed 7 days before the start of drug administration. Morphine hydrochloride (20 mg/kg/day s.c.), buprenorphine (0.05 mg/kg/day s.c.), or naloxone hydrochloride dihydrate (2 mg/kg/day s.c.) were administered for 4 weeks to NOVX and OVX rats. In OVX rats, the use of morphine and buprenorphine counteracted the development of osteoporotic changes in the skeletal system induced by estrogen deficiency. Morphine and buprenorphine beneficially affected also the skeletal system of NOVX rats, but the effects were much weaker than those in OVX rats. Naloxone generally did not affect the rat skeletal system. The results confirmed the role of opioid receptors in the regulation of bone remodeling processes and demonstrated, in experimental conditions, that the use of opioid analgesics at moderate doses may exert beneficial effects on the skeletal system, especially in estrogen deficiency.
authors.affiliation: Department of Pharmacology, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Katowice, Poland.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Janas
authors.affiliation: Department of Pharmacology, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Katowice, Poland. jfolwarczna@sum.edu.pl.
authors.forename: Joanna
authors.initials: J
authors.lastname: Folwarczna
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D001696:Biomechanical Phenomena; D016723:Bone Remodeling / Q000187:drug effects*; D002047:Buprenorphine / Q000494:pharmacology*; D019245:Compressive Strength; D004195:Disease Models, Animal; D054333:Drug Partial Agonism; D055119:Elastic Modulus; D005260:Female; D005269:Femur / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D010052:Ovariectomy; D017208:Rats, Wistar; D017473:Receptors, Opioid, kappa / Q000037:antagonists & inhibitors / Q000378:metabolism; D017450:Receptors, Opioid, mu / Q000819:agonists* / Q000378:metabolism; D013977:Tibia / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology
chemical_list: D000701:Analgesics, Opioid; D009292:Narcotic Antagonists; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D009270:Naloxone; D002047:Buprenorphine; D009020:Morphine
keywords: Bone mechanical properties; Opioids; Osteoporosis; Rats