Protective Effect Of Morphine Research Articles

A study on protective effect of morphine against myocardial ischemia-reperfusion injury in rats via CAMP/PKA signaling pathway.

The purpose of this study was to explore the mitigating effect of morphine on the myocardial ischemia-reperfusion injury (MIRI) in rats through the cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) pathway. A total of 30 male Wistar rats were assigned into sham group, MIRI group and morphine group using a random number table. The model of MIRI was routinely established. Then, the pathological changes in the morphology of myocardial tissues were observed via hematoxylin-eosin (HE) staining. The levels of the oxidative stress indicators superoxide dismutase (SOD) and malondialdehyde (MDA), the content of the inflammatory cytokine tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β) and IL-6 and the quantity of glutathione peroxidase (GSH-Px), lactate dehydrogenase (LDH), creatine kinase (CK), CK-MB and cardiac troponin I (cTnI) in the myocardial enzyme spectrum were determined and analyzed through enzyme-linked immunosorbent assay (ELISA). Moreover, the messenger ribonucleic acid (mRNA) and protein expressions of cAMP, PKA, cAMP-response element binding protein (CREB) and phosphorylated CREB (p-CREB) in the cAMP/PKA signaling pathway in the myocardial tissues were measured using real-time polymerase chain reaction (PCR) and Western blotting, respectively. The results manifested that compared with those in MIRI group, the levels of myocardial infarct size, LDH, CK, CK-MB, cTnI, MDA, TNF-α, IL-1β, IL-6 and p-CREB were decreased, while the levels of GSH-Px, SOD, PKA and CREB were increased in the morphine group. In conclusion, morphine may mitigate MIRI in rats through the cAMP/PKA signaling pathway.

Induction of cross-tolerance between protective effect of morphine and nicotine in 6-hydroxydopamine-induce neurotoxicity in SH-SY5Y human dopaminergic neuroblastoma cells

Purpose: Parkinson’s disease is a progressive neurodegenerative disease characterized by progressive and selective death of dopaminergic neurons. It has been reported that nicotine and morphine have protective roles during neuronal damage in Parkinson’s disease. In addition, the induction of cross-tolerance between their biological effects has been shown in numerous reports.Methods: Here, we investigated the effects of nicotine and morphine on 6-OHDA-induced neurotoxicity in human neuroblastoma SH-SY5Y cell line as an in vitro model of Parkinson’s disease. Cell damage was induced by 150 μM 6-OHDA and the cells viability was examined by MTT assay. Intracellular reactive oxygen species, calcium level, and mitochondrial membrane potential were determined by fluorescence spectrophotometer method. Biochemical markers of apoptosis were also evaluated by immunoblotting.Result: The data showed that morphine and nicotine prevent 6-OHDA- induced cell damage and apoptosis. However, the protective effects of nicotine were not observed in chronic morphine-pretreated cells. Morphine had no protective effects in chronic nicotine-incubated cells.Conclusion: A cross-tolerance between protective effects of morphine and nicotine was occurred in 6-OHDA-induced SH-SY5Y cell toxicity.

Protective Effect of Morphine Against the Oxidant-Induced Injury in H9c2 Cells.

There are some indications that morphine may exert myocardial protective effects under certain conditions. The aim of the present study was to investigate the effect of morphine on viability and oxidative state of H9c2 cells (rat cardiomyoblasts) influenced by oxidative stress that was elicited by exposure to tert-butyl hydroperoxide (t-BHP). Our experiments showed that pretreatment with morphine before the addition of t-BHP markedly improved cell viability. Morphine was able to increase total antioxidant capacity of H9c2 cells and to reduce the production of reactive oxygen species, protein carbonylation, and lipid peroxidation. Cellular damage caused by t-BHP was associated with low levels of p38 MAPK and GSK-3β phosphorylation. Pretreatment with morphine augmented p38 phosphorylation, and the increased phospho-p38/p38 ratio was preserved even in the presence of t-BHP. Morphine did not change the level of GSK-3β phosphorylation, but interestingly, the phospho-GSK-3β/GSK-3β ratio significantly increased after subsequent incubation with t-BHP. Furthermore, morphine exposure resulted in upregulation of the antioxidant enzyme catalase. The protective effect of morphine was abrogated by the addition of the PI3K inhibitor wortmannin and/or p38 MAPK inhibitor SB203580. It can be concluded that morphine may protect H9c2 cells against oxidative stress and that this protection is at least partially mediated through activation of the p38 MAPK and PI3K/GSK-3β pathways.

Morphine Protects Spinal Cord Astrocytes from Glutamate-Induced Apoptosis via Reducing Endoplasmic Reticulum Stress.

Glutamate is not only a neurotransmitter but also an important neurotoxin in central nervous system (CNS). Chronic elevation of glutamate induces both neuronal and glial cell apoptosis. However, its effect on astrocytes is complex and still remains unclear. In this study, we investigated whether morphine, a common opioid ligand, could affect glutamate-induced apoptosis in astrocytes. Primary cultured astrocytes were incubated with glutamate in the presence/absence of morphine. It was found that morphine could reduce glutamate-induced apoptosis of astrocytes. Furthermore, glutamate activated Ca2+ release, thereby inducing endoplasmic reticulum (ER) stress in astrocytes, while morphine attenuated this deleterious effect. Using siRNA to reduce the expression of κ-opioid receptor, morphine could not effectively inhibit glutamate-stimulated Ca2+ release in astrocytes, the protective effect of morphine on glutamate-injured astrocytes was also suppressed. These results suggested that morphine could protect astrocytes from glutamate-induced apoptosis via reducing Ca2+ overload and ER stress pathways. In conclusion, this study indicated that excitotoxicity participated in the glutamate mediated apoptosis in astrocytes, while morphine attenuated this deleterious effect via regulating Ca2+ release and ER stress.

Morphine-induced delayed pre-conditioning against anoxia/reoxygenation injury in pulmonary artery endothelial cells: The role of mitochondrial KATP channels.

Opioids produce delayed pre-conditioning (PC) in vivo and in vitro. Our previous research revealed that opioid‑induced delayed PC has an antiapoptotic effect on pulmonary artery endothelial cells (PAECs) suffering from anoxia/reoxygenation (A/R) injury. The present study hypothesized that activation of endothelial mitochondrial ATP‑sensitive potassium (KATP) channels may result in antiapoptotic effects and against dysfunction in PAECs. Cultured porcine PAECs underwent 16 h anoxia treatment, followed by 1 h reoxygenation, which occurred 24 h following pretreatment with saline (0.9% NaCl; w/v) or morphine (1 µM). To determine the underlying mechanism, a selective mitochondrial KATP inhibitor, 5‑hydroxydecanoic acid (5‑HD; 100 µM), and an opioid receptor antagonist, naloxone (Nal; 10 µM), were administered 30 min prior to the A/R load. The percentage of apoptotic cells was assessed by Annexin V‑fluorescein isothiocyanate staining, using a fluorescence‑activated cell sorter. The mRNA expression of intercellular cell adhesion molecule‑1 (ICAM‑1) was measured by reverse transcription‑quantitative polymerase chain reaction. The endothelin‑1 (ET‑1) content in the supernatant of PAECs cultures was estimated by radioimmunoassay. Compared with the control, A/R caused the apoptosis of PAECs, release of ET‑1 and increased mRNA expression of ICAM‑1. Morphine‑induced delayed PC significantly reduced PAEC apoptosis, increased the release of ET‑1 and reduced the mRNA expression of ICAM‑1 by ~1.7‑times, compared with A/R. The protective effect of morphine was abolished by pretreatment with 5‑HD and Nal, however, the two agents themselves failed to aggravate the A/R injury. These results suggested that morphine-induced delayed PC has a protective effect during A/R injury of PAECs. This effect may be mediated by mitochondrial KATP channels and is opioid receptor-dependent.

Protective Effects of Morphine on Serum Deprivation-induced Cell Death in PC12 Cells

Protective Effects of Morphine on Serum Deprivation-induced Cell Death in PC12 Cells

Cytoprotective effects of opioids on irradiated oral epithelial cells

Oral mucositis is a common side effect of chemotherapy and radiation therapy accompanied with acute inflammation and ulceration of the oral mucosa. Opioids can improve the wound healing of dermal and oral tissue when applied locally. The aim of this study was to investigate if morphine exhibits cytoprotective effects on oral epithelial cells postirradiation. Hence, oral epithelial cells were exposed to increasing doses (3-30 Gy) of ionization radiation. We assessed the effects of the radiation on cell viability, proinflammatory cytokine release (interleukin [IL]-1α, IL-6), and matrix metalloproteinase (MMP-1, -8, and -9) expression. As expected, radiation significantly impaired cell viability and morphology and resulted in enhanced IL release. However, morphine-treated cells consistently showed higher cell viability postirradiation: 9.19 ± 1.16% after 24 hours and 7.45 ± 0.93% after 48 hours compared with the control. In terms of proinflammatory cytokines, the release of IL-1α and IL-6 was significantly reduced, too, being most pronounced at 48 hours postradiation. Additionally, we observed a significant reduction of MMP-1 and especially MMP-9 expression in morphine-treated cells. The results clearly indicate anti-inflammatory as well as cytoprotective effects of morphine on irradiated oral epithelial cells. Interestingly, the protective effects of morphine are not related to a decrease in cell apoptosis or necrosis. Before final conclusions can be drawn, further studies in more complex systems in vitro and in vivo are required. Nevertheless, these findings further underline the high potential of opioids for the treatment of topical wounds and inflammatory conditions.

Bisphosphonate treatment may reduce osteoporosis risk in female cancer patients with morphine use: a population-based nested case–control study

Chronic use of morphine is a risk factor for endocrinopathy and osteoporosis. Bisphosphonates accentuated the protective effect to develop osteoporosis in female patients with malignancy with morphine treatment. This study investigates the risk of osteoporosis associated with morphine use by comparing the incidence of osteoporosis in female cancer patients treated with and without morphine. A population-based nested case-control retrospective analysis was performed using the Longitudinal Health Insurance Database 2000 and Registry for Catastrophic Illness Patients of Taiwan. A malignancy cohort of 12,467 female patients without a history of osteoporosis during 1998-2010, and then 639 patients who subsequently developed osteoporosis as the osteoporosis group, were evaluated. Control-group patients were selected from the malignancy cohort without osteoporosis and frequency matched to each osteoporosis case 2:1 for age, year of cancer diagnosis, and index year. Logistic regression was used to estimate the odds ratios and 95% confidence intervals, and the multivariable model was applied to control for age. Female cancer patients who received morphine had a 10% lower risk of developing osteoporosis than non-morphine users, but this risk reduction was not significant. For patients treated with bisphosphonates, the morphine group had significantly lower odds in developing osteoporosis than the non-morphine group. Morphine treatment is not associated with the incidence of osteoporosis, and bisphosphonates accentuated the protective effect of morphine in the development of osteoporosis in female patients with malignancy in Taiwan.

MORPHINE PREVENTS OXIDANT STRESS-INDUCED MITOCHONDRIAL DAMAGE VIA AN EGFRTK-ROS-AKT SIGNALLING PATHWAY IN H9C2 CARDIAC MUSCLE CELLS

Objectives AimsWe previously documented that morphine upregulates Akt activity by inactivating protein Ser/Thr phosphatases via reactive oxygen species (ROS) may contribute to the protective effect of morphine on ischaemia/reperfusion injury,...

Factors affecting theprotective effect of morphine preconditioning on murine hippocampal neurons againstanoxia-reoxygenation injury

：Objective To investigatethe factors affecting the protective effects of morphine preconditioning on murinehippocampal neurons against anoxia/reoxygenation (A/R) injury and the underlyingmechanisms.Methods Hippocampal slices (400 μm thick) were prepared usinghippocampi isolated from decapitated mice. A/R injury was simulated in vitro usingartificial cerebral spinal fluid (ACSF) deprived of O_2 and glucose for 20 min followed byreoxygenation and glucose supply for 2 h. The experiment was performed in 4 parts: I .Theslices were incubated with 5 different concentrations of morphine (0.1, 0.3, 0.5, 1.0,3.0, 10.0 /μmol/L) for 30 min at 30 min before A/R; Ⅱ.The slices were incubated with morphine 3.0 /μmol/L for 5 different periodsof time (5, 15, 30, 45, 60 min) at 30 min before A/R; Ⅲ. The slices were incubatedwith morphine 3.0 μmol/L for 30 min followed by A/R at 6 differentintervals (0, 5, 15,30,60, 120 min); Ⅳ. The slices were incubatedwith (a) chelerythrine (a non-selective PKC antagonist) 10 /μmol/L or (b) eVl-2(a selective nPKCe isoform antagonist) 2 μmol/L or (c) AIP 2 μmol/L(a selective CaMK Ⅱ antagonist) or (d) MK-801 10μmol/L (a non-competitive NMDA receptor blocker) for 30 min and then for another30 min together with morphine 3.0 μmol/L before A/R at 30 mininterval. The survival rates of the hippocampal neurons were assessed by TTC staining.Results Neuronal survival rates were significantly higher in morphine preconditioninggroups which preconditioned with morphine (0.5-10.0 μmol/L) for 15-60 min at aninterval of 0-60 min before A/R than in A/R group. Increase in neuronal survival rateinduced by morphine preconditioning was partially blocked by chelerythrine or eV1-2or AIP or MK-801. Conclusion Preconditioning with appropriate concentrations of morphine(0.5-10.0 μmol/L) for appropriate period of time (15-60 min) at appropriateinterval (within 60 min) before A/R can protect hippocampal neurons against A/R injurythrough activation of nPKCe, NMDA receptor and CaMKⅡ. Key words: Morphine; Ischemicpreconditioning; Hippocampus; Neurons; Reperfusion injury

Effect of morphine on Mycobacterium smegmatis infection in mice and macrophages

The immunomodulatory effects of opioids are known in various infections. However, little is known about the effects of opioids in tuberculosis (TB). In the present study, we report the effects of morphine in Mycobacterium smegmatis infection in mice and macrophages. Morphine exerted a dose-dependent suppression of infection in vivo: 50 and 100 mg/kg morphine exerted significant (P<0.05) suppression whereas 5 mg/kg morphine showed no effect. Analogous to the in vivo effects, incubation of M. smegmatis-infected mouse peritoneal macrophages with morphine (100 μM) showed significant reduction in intramacrophage CFU counts. However, morphine did not show any direct antimycobacterial activity in broth dilution assay upto 100 μM concentration. Further, morphine-induced intramacrophage killing of M. smegmatis was abrogated by naloxone and aminoguanidine indicating the involvement of opioid-receptor activation and nitric oxide production in protective effects of morphine. In conclusion, morphine suppressed the progression of experimental TB in both mice and macrophage models.

Role of nitric oxide in the protective effect of morphine postconditioning against ischemia-reperfusion-induced myocardial apoptosis

Objective To investigate the role of nitric oxide (NO) in the protective effects of morphine postconditioning against ischemia-reperfusion (I/R)-induced myocardial apoptoais. Methods Sixty pathogen-free SD rats were randomly divided into 4 groups ( n = 15 each) : group Ⅰ sham operation (S) ; group Ⅱ I/R; group Ⅲ morphine postconditioning ( M ) and group Ⅳ M + L-NAME ( non-selective NOS inhibitor). The animals were anesthetized with intraperitoneal pentobarbital 60 mg/kg, tracheostomized and mechanically ventilated. ECG was monitored. Right carotid artery was cannulated for BP monitoring and left jugular vein was cannulated for drug and fluid administration. Myocardial ischemia was induced by 45 min occlusion of left anterior descending coronary artery (LAD) followed by 120 min reperfusion. In group S LAD was exposed but not occluded; in group M morphine 1.25 mg/kg was injected iv over 5 min from 3 min before reperfuaion to 2 min of repeffuaion and in group M + L-NAME L-NAME 10 mg/kg was injected iv at 20 min before myocardial ischemia. Hemodynamic changes were monitored. The animals were killed at the end of 120 min reperfusion and their hearts removed. Myocardial apoptosis was determined by TUNEL technique. The expression of Akt phosphorylation was assessed by Western blotting. The NO content in myocardium was measured by a chemiluminescence detector.Results A large number of TUNEL positive cells (18.4 ± 1.1 ) % were observed in group I/R. Morphine postconditioning exerted a significant anti-apoptotic effect. The number of TUNEL positive cells was reduced to (10.8 ± 1.2)%. The myocardial eNOS phosphorylation expression and NO content were significantly increased in group M as compared with group I/R. The anti-apoptofie effect and increased NO production were significantly reversed by L-NAME. However, pretreatment with L-NAME did not inhibit the phosphorylation of eNOS in group L + M. Conclusion In vivo, morphine postconditioning can significantly reduce I/R-induced myocardial apoptosis through phosphorylation of eNOS and increase in NO production. Key words: Nitric oxide; Morphine; Myocardial reperfusion injury; Apoptosis

MORPHINE PRETREATMENT PROVIDES HISTOLOGIC PROTECTION AGAINST ISCHEMIA-REPERFUSION INJURY IN RABBIT RETINA

Pharmacologic preconditioning with morphine has been shown to protect several kinds of tissues against ischemia-reperfusion injury. The aim of the present study was to investigate whether intravitreal administration of morphine induces structural protection against ischemic damage in a rabbit model of ischemic retinopathy. Twenty-eight male white New Zealand rabbits were used. Animals in saline control group received 0.1 mL of phosphate-buffered saline (PBS) intravitreally with no postinjection ischemia. In the saline-control ischemia group, 15 minutes after injection of PBS, retinal ischemia was induced by raising intraocular pressure to 150 mmHg for 60 minutes. In three treatment-ischemia groups, morphine (1, 5, and 10 micromol/L) was administered intravitreally 15 minutes before induction of ischemia. In another experiment, naloxone (40 micromol/L) was administered 5 minutes before intravitreal administration of morphine (10 micromol/L) followed by 60 minutes of ischemia to investigate the role of opioid receptors in mediating the possible protective effect of morphine. Toxicity controls were performed with morphine (10 micromol/L) and naloxone (40 micromol/L) without ischemia. Histologic evaluation was performed for all groups on the seventh postoperative day. Sixty minutes of ischemia led to severe cell loss in ganglion cell layer and thinning of the inner nuclear layer in saline-control ischemia compared to that of the nonischemia control group (P < 0.001). Thickness of the inner plexiform layer to the inner limiting membrane was significantly increased due to edema (P < 0.001). Administration of morphine in higher doses (5 and 10 micromol/L) significantly improved all of the above mentioned indices (P < 0.05). Administration of naloxone 15 minutes before morphine reversed most of the morphine protective effects. Morphine pretreatment provides significant histologic protection against ischemic injury in rabbit retina. Pharmacologic evidence suggests that this protective phenomenon may be mediated in part by opiate receptors.

Morphine modulates inducible nitric oxide synthase expression and reduces pulmonary oedema induced by α-naphthylthiourea

This study was designed to investigate the possible participation of morphine in pulmonary oedema induced by α-naphthylthiourea (ANTU), which is a well-known noxious chemical agent in the lung. Injection of ANTU (15 mg/kg i.p.) produced pulmonary oedema as indicated by an increase in lung weight/body weight ratio and pleural effusion reaching a maximum within 4 h in rat. Administration of morphine prior to ANTU significantly inhibited to pulmonary oedema with a dose-dependent manner. The protective effect of morphine is prevented by peripheral opioid receptor antagonist, naloxone methiodide. ANTU-treated rats were shown positive by inducible nitric oxide synthase immunohistochemical staining. There was no staining in the control group. On the other hand, the degree of staining was markedly reduced in tissue sections by morphine. These results suggest that previous administration of subcutaneous morphine has preventive effect on ANTU-induced pulmonary inflammatory reaction and its effect mediated via peripheral opioid receptors. Application of naloxone with ANTU has no effect on the lung parameters indicating that endogenous opioids do not modulate ANTU-induced damage.

Morphine prevents peroxynitrite-induced death of human neuroblastoma SH-SY5Y cells through a direct scavenging action

N-Ethyl-2-(1-ethyl-2-hydroxy-2-nitrosohydrazino)-ethanamine (NOC12), a nitric oxide donor, 3-morpholinosydnonimine (SIN-1), a generator of peroxynitrite (ONOO −), and peroxynitrite induced cell death accompanied by DNA fragmentation in human neuroblastoma SH-SY5Y cell cultures. Morphine prevented the cell death induced by SIN-1 or peroxynitrite, but not that induced by NOC12. The protective effect of morphine was concentration-dependent (10–100 μM), but was not antagonized by naloxone. The selective ligands for opioid receptor subtypes, [ d-Ala 2, N-Me-Phe 4, Gly-ol 5]enkephalin (DAMGO, μ-opioid receptor agonist), [ d-Pen 2,5]enkephalin (DPDPE, δ-opioid receptor agonist) and trans-(±)-3,4-dichloro- N-methyl- N-(2-[1-pyrrolidinyl]-cyclohexyl)benzeneacetamide (U-50488, κ-opioid receptor agonist) even at the concentration of 100 μM did not prevent the cell death induced by SIN-1. From measurement of the absorbance spectrum of peroxynitrite, the decomposition of peroxynitrite in 0.25 M potassium phosphate buffer (pH 7.4) was very rapid and complete within seconds. However, the absorbance was very stable in the presence of morphine. In addition, morphine inhibited peroxynitrite-induced nitration of tyrosine in a concentration-dependent manner. These results indicate that morphine rapidly reacts with peroxynitrite. The present study showed that morphine prevented peroxynitrite-induced cell death through its direct scavenging action, suggesting that morphine can protect cells against damage caused by peroxynitrite.

The effects of morphine and traumatic brain injury on central cholinergic neurons

This study examined the effects of morphine and fluid percussion traumatic brain injury (TBI) on the activity of cholinergic neurons in specific areas of the rat brain 12 min after injury. Acetylcholine (ACh) turnover, used as an index of cholinergic neuronal activity, was determined using gas chromatography-mass spectrometry. Although morphine administration alone in general did not significantly affect ACh content and turnover in specific brain areas, morphine administered prior to TBI either prevented injury-induced changes in ACh turnover (dorsal pontine tegmentum) or actually reduced the rate constant for ACh utilization ( k ACh) and the turnover rate of ACh (TR ACh) following injury (thalamus, amygdala, cingulate/frontal cortex, and hippocampus). Thus, the protective effects of morphine against enduring behavioral deficits following TBI may involve the inhibition of central cholinergic neurons.