Different Concentrations Of Morphine Research Articles

Low concentrations of morphine enhanced the neuroglia-like differentiation

The present study was undertaken to evaluate the effects of different concentrations of morphine in chronic manner on neuroglial differentiation in PC12 cells. PC12 cells were cultured in RPMI 1640 culture medium including 0.02 % bovine serum albumin together with different concentrations of morphine for 12 days. Cytotoxicity was performed by lactate dehydrogenase assay. Cell death was performed by PI/Hoechst staining assay. Neuroglial differentiation was performed by Nestin, Tuj-1, MAP-2, S-100 and GFAP Immunocytochemistry assay. Data showed that morphine either at low or high concentration activated opioid receptors, which resulted in a decrease of cytotoxicity and cell death and induction of Nestin, Tuj-1, MAP-2, Neurofilament-M (NF-M), GFAP and S-100 protein expression as compared in treated cells with the control (untreated cells) (p<005). It can be concluded that low concentrations of morphine in chronic manner stimulate the neuroglial-like differentiation by activating protein expression and survival-promoting signaling in PC12 cells with opioid receptor-dependent mechanism (Fig. 8, Ref. 36). Text in PDF www.elis.sk.

Molecular modeling and experimental study of a new peptide-based microextraction fiber for preconcentrating morphine in urine samples.

Antimicrobial peptides (AMPs) are best known for their bactericidal properties; however, due to their unique and flexible structures, they have also been proposed as potential selective sorbents for specific molecules. In the present study, we aimed to design and produce a new peptide-based microextraction fiber for preconcentrating morphine in urine samples. The binding of morphine to the peptide was first evaluated by computational simulation using the Molecular Operating Environment (MOE) 2015.10 software. A similar study was then performed using DS BIOVIA Materials Studio 2017 v17.1.0.48, which confirmed the results of the simulation carried out with MOE. Afterwards, those results were also confirmed by experimental research. In the experimental evaluation, carbon nanotubes (CNTs) were initially carboxylated with H2SO4/HNO3 (3:1) and then functionalized with the peptide. FTIR analysis, Raman measurements, and SEM imaging were used to confirm that CNT functionalization was successful as well as to check the nanostructure of the fiber. To evaluate the functionality of the fiber, it was inserted into a microtube containing a urine sample that included morphine and then sonicated for 5min at 40°C. Afterwards, the fiber was washed with methanol 20% (H2O/methanol) and the resulting sample was analyzed by HPLC. This procedure was repeated for different concentrations of morphine in the urine sample. The computational and experimental results showed that a morphine concentration as low as 0.25ppb in urine could be adsorbed and detected using the peptide fiber. Therefore, given its semi-selective binding affinity for morphine, this peptide-based fiber can be considered a new approach to the detection of small amounts of morphine in biological samples.

Short term morphine exposure in vitro alters proliferation and differentiation of neural progenitor cells and promotes apoptosis via mu receptors.

BackgroundChronic morphine treatment inhibits neural progenitor cell (NPC) progression and negatively effects hippocampal neurogenesis. However, the effect of acute opioid treatment on cell development and its influence on NPC differentiation and proliferation in vitro is unknown. We aim to investigate the effect of a single, short term exposure of morphine on the proliferation, differentiation and apoptosis of NPCs and the mechanism involved.MethodsCell cultures from 14-day mouse embryos were exposed to different concentrations of morphine and its antagonist naloxone for 24 hours and proliferation, differentiation and apoptosis were studied. Proliferating cells were labeled with bromodeoxyuridine (BrdU) and cell fate was studied with immunocytochemistry.ResultsCells treated with morphine demonstrated decreased BrdU expression with increased morphine concentrations. Analysis of double-labeled cells showed a decrease in cells co-stained for BrdU with nestin and an increase in cells co-stained with BrdU and neuron-specific class III β-tubuline (TUJ1) in a dose dependent manner. Furthermore, a significant increase in caspase-3 activity was observed in the nestin- positive cells. Addition of naloxone to morphine-treated NPCs reversed the anti-proliferative and pro-apoptotic effects of morphine.ConclusionsShort term morphine exposure induced inhibition of NPC proliferation and increased active caspase-3 expression in a dose dependent manner. Morphine induces neuronal and glial differentiation and decreases the expression of nestin- positive cells. These effects were reversed with the addition of the opioid antagonist naloxone. Our results demonstrate the effects of short term morphine administration on the proliferation and differentiation of NPCs and imply a mu-receptor mechanism in the regulation of NPC survival.

Role of Different Concentrations of Morphine after Coronary Perfusion for Myocardial Protection

Role of Different Concentrations of Morphine after Coronary Perfusion for Myocardial Protection

The effects of opioids on HIV reactivation in latently-infected T-lymphoblasts.

BackgroundOpioids may have effects on susceptibility to HIV-infection, viral replication and disease progression. Injecting drug users (IDU), as well as anyone receiving opioids for anesthesia and analgesia may suffer the clinical consequences of such interactions. There is conflicting data between in vitro experiments showing an enhancing effect of opioids on HIV replication and clinical data, mostly showing no such effect. For clarification we studied the effects of the opioids heroin and morphine on HIV replication in cultured CD4-positive T cells at several concentrations and we related the observed effects with the relevant reached plasma concentrations found in IDUs.MethodsLatently-infected ACH-2 T lymphoblasts were incubated with different concentrations of morphine and heroine. Reactivation of HIV was assessed by intracellular staining of viral Gag p24 protein and subsequent flow cytometric quantification of p24-positive cells. The influence of the opioid antagonist naloxone and the antioxidants N-acetyl-cysteine (NAC) and glutathione (GSH) on HIV reactivation was determined. Cell viability was investigated by 7-AAD staining and flow cytometric quantification.ResultsMorphine and heroine triggered reactivation of HIV replication in ACH-2 cells in a dose-dependent manner at concentrations above 1 mM (EC50 morphine 2.82 mM; EC50 morphine 1.96 mM). Naloxone did not interfere with heroine-mediated HIV reactivation, even at high concentrations (1 mM). Opioids also triggered necrotic cell death at similar concentrations at which HIV reactivation was observed. Both opioid-mediated reactivation of HIV and opioid-triggered cell death could be inhibited by the antioxidants GSH and NAC.ConclusionsOpioids reactivate HIV in vitro but at concentrations that are far above the plasma levels of analgesic regimes or drug concentrations found in IDUs. HIV reactivation was mediated by effects unrelated to opioid-receptor activation and was tightly linked to the cytotoxic activity of the substances at millimolar concentrations, suggesting that opioid-mediated reactivation of HIV was due to accompanying effects of cellular necrosis such as activation of reactive oxygen species and NF-κB.

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Objective: To investigate whether the different concentrations of morphine after coronary perfusion have myocardial protection. Subjects and method: Forty-five patients undergoing heart valve replacement were randomly divided into three groups of 15 patients: group A (morphine 2 µmol/L in the cardioplegic solution), group B (morphine 4 µmol/L in the cardioplegic solution) and group C (no morphine in the cardioplegic solution). The three groups were monitored before induction (T1), five minutes before (T2) and five minutes after (T3) cardiopulmonary bypass (CPB), perioperative (T4) for haemodynamic parameters, two hours after CPB (T5) and 24 hours after CPB (T6). The postoperation incidence of severe ventricular arrhythmia and low cardiac output, CPB transit time, aortic cross-clamp time, defibrillation time, duration of ventilation and intensive care unit (ICU) and hospital stay were recorded. Results:The levels of cardiac troponin I (cTnI) at T5 and T6 in group A and group B were significantly lower than those in group C (p < 0.05), and at T6 in group B, were lower than those in group A (p < 0.05). The levels of CK-MB at T6 in group B were lower than those in group C (p < 0.05). The morphological changes in group A and group B were less than those in group C; and the least in group B. Conclusion:Morphine at concentrations of 2 µmol/L and 4 µmol/L after coronary perfusion on cardiac valve replacement with CPB has myocardial protection; 4 µmol/L of morphine provides more myocardial protection.

In vitro morphine metabolism by rat microglia

Morphine is mainly transformed to morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) in the liver. Glucuronidation is also performed by rat brain homogenates and UDP-glucuronosyltransferases (UGTs) are present in the brain. Here we investigated the possibility that microglia transforms morphine into its metabolites M3G and M6G. Primary cultures of neonatal rat microglia were incubated for different intervals of time in basal conditions or with different concentrations of morphine. The following measures were performed on these cultures and/or in the medium: (i) morphine as well as M3G and M6G concentrations; (ii) levels of mRNA coding for UGT1A1, UGT1A6, UGT1A7, and UGT2B1 as well as their protein levels; (iii) released prostaglandin (PG)E2 and nitrite concentrations. Results show that in basal conditions morphine and M3G are produced by microglia; accordingly, these cells expressed UGT1A1, UGT1A6 and UGT1A7, but not UGT2B1. When cultures were exposed to different concentrations of exogenous morphine, M6G was also synthesized. This shift in the glucuronidation was associated with variations in the expression of UGT isozymes. In particular, UGT1A7 expression was rapidly upregulated and this event was translated into enhanced protein levels of UGT1A7; lesser effects were exerted on UGT1A1 and UGT1A6. Upon prolonged exposure to morphine, microglial cell UGT expression returned to baseline conditions or even to reduced levels of expression. Morphine exposure did not affect the synthesis of both PGE2 and nitrites, ruling out a generalized priming of microglia by morphine. In conclusion, this study suggests that morphine glucuronides found in the cerebrospinal liquor upon peripheral morphine administration may at least in part be brain-born, reconciling the conceptual gap between the high hydrophilic features of morphine glucuronides and their presence beyond the blood–brain barrier.

The effect of different concentrations of morphine and extracellular Ca2+ on cell death in PC12 cell line

The effect of different concentrations of morphine and extracellular Ca2+ on cell death in PC12 cell line

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

Prolonged morphine application modulates Bax and Hsp70 levels in primary rat neurons

Morphine has been used for pain treatment with a long history. Some data suggest that morphine is toxic to neurons and induces apoptosis, while other evidence shows that morphine could have beneficial effects against cell death. To determine how morphine affects pro-apoptotic protein Bax and molecular chaperone Hsp70, different concentrations of morphine were examined. Our results show that prolonged morphine administration for 5 days at 1microM concentration protects against serum deprivation induced cell death in rat primary neurons. Morphine treatment decreases Bax and Hsp70 levels in cultured rat primary neurons, suggesting morphine may have a protective role in staurosporine and serum deprivation induced cytotoxicity.

Kinetic determination of morphine by means of Bray–Liebhafsky oscillatory reaction system using analyte pulse perturbation technique

A novel kinetic method for micro-quantitative determinations of morphine (MH) is proposed and validated. The method is based on the potentiometric monitoring of the concentration perturbations of the oscillatory reaction system being in a stable non-equilibrium stationary state close to the bifurcation point between stable and oscillatory state. The response of the Bray–Liebhafsky (BL) oscillatory reaction as a matrix system, to the perturbations by different concentrations of morphine, is followed by a Pt-electrode. The proposed method relies on the linear relationship between maximal potential shift, Δ E m, and the logarithm of the added morphine amounts in the range of 0.004–0.18 μmol. Under optimum conditions, the sensitivity of the proposed method (as the limit of detection) is 0.001 μmol and the method is featured by good precision (R.S.D. = 1.6%) as well as the excellent sample throughput (45 samples h −1). In addition to standard solution analysis, this approach was successfully applied for quantitative determination of morphine in a typical pharmaceutical dosage form. Some aspects of the possible mechanism of morphine action on the BL oscillating chemical system are discussed in detail.

Postoperative continuous intrathecal pain treatment in children after selective dorsal rhizotomy with bupivacaine and two different morphine doses

Children undergoing selective dorsal rhizotomy (SDR) experience severe pain postoperatively; a pain related to both the extensive surgical exposure with multilevel laminectomy and nerve root manipulation. We sought to define an optimal dose of continuous intrathecal (IT) morphine and bupivacaine to treat this severe pain. The aim of this study was to compare two different concentrations of morphine in a fixed dose of bupivacaine with regard to the analgesic effect and survey if they differed in side effects. Twenty-six children, aged 2.7-7.4 years undergoing SDR were included in this study. Postoperatively 11 children received a continuous infusion of morphine 0.4 microg x kg(-1) x h(-1) and bupivacaine 40 microg x kg(-1) x h(-1) (low-dose group) and 15, a continuous infusion of morphine 0.6 microg x kg(-1) x h(-1) and bupivacaine 40 microg x kg(-1) x h(-1) (high-dose group). The Behavioral Observational Pain Scale (BOPS) was used to evaluate pain. Better pain relief was obtained in the high-dose group seen in lower BOPS score compared with the low-dose group [P = 0.03, Fisher's permutation test and P = 0.06 Wilcoxon-Mann-Whitney (WMW) test]. The low-dose group received seven times as much ketobemidone 0.43 +/- 0.54 mg x kg(-1) 48 h(-1) compared with 0.06 +/- 0.09 mg x kg(-1) 48 h(-1) in the high-dose group (P = 0.0005 Fisher's permutation test, P = 0.0017 WMW test). There was no statistical difference in pruritus and postoperative nausea and vomiting between the groups. Respiratory and hemodynamic depression was not found. This study shows that, compared with low-dose, the higher dose of continuous IT morphine combined with bupivacaine, significantly reduce pain score and postoperative intravenous analgesic requirements without increasing adverse effects.

Determination of Drug Levels in Larvae of Lucilia sericata (Diptera: Calliphoridae) Reared on Rabbit Carcasses Containing Morphine

This study concerns the determination of morphine concentrations in fly larvae reared on rabbits administered different concentrations of morphine and a correlation between concentrations of the drug in larvae and tissues. Three rabbits (R1, R2 and R3) were given dosages of 12.5, 25.0 and 50.0 mg/h of morphine over a 3 h period via continuous ear artery perfusion. These dosages and time of perfusion were calculated to create tissue concentrations of morphine similar to those encountered in human death due to overdose. Morphine blood level plateau was attained after 1 h of perfusion. A fourth rabbit was used as a control. To evaluate drug concentrations, tissues were sampled using a coelioscopic technique. Approximately 400 eggs of Lucilia sericata, all of the same age category, were placed in eyes, nostrils and mouth of each rabbit carcass. Larvae and puparia were regularly collected from each rabbit for toxicological analysis. The concentrations of the drug in the tissues sampled were determined to be similar to those normally encountered in human overdoses and were correlated with the dosage of morphine that had been administered. Morphine was detected in all larvae and pupae fed on tissues from carcasses administered morphine, except for puparia from the colony fed on the R1 animal which received 12.5 mg/h dosage of morphine. All samples from the control rabbit were negative for morphine. Concentrations of morphine in larvae reared on rabbit carcasses containing morphine were 30 to 100 times lower than the concentrations found in the tissues. A correlation between the tissue concentrations and larval concentrations was found in only 3rd instar larvae (80 to 140 h following hatching). No correlations were found between administered dosages, tissue concentrations and younger larvae, prepuparial larvae or puparia.

Morphine alters the levels of growth hormone receptor mRNA and [ 125I]growth hormone binding in human IM-9 lymphoblasts via a naloxone-reversible mechanism

The immune system and the neuroendocrine system are functionally interactive. Lymphocytes possess opioid receptors as well as growth hormone receptors (GHR) by which opioids and growth hormone (GH) may modulate immune functions. In this study, we have investigated the effects of morphine on [ 125I]hGH binding and GHR gene expression in human lymphoblastoid IM-9 cells. Northern blot analysis revealed significantly altered GHR mRNA levels after treatment of the cells with different concentrations of morphine for 12 h. Morphine at 10 μM increased the mRNA levels in a time-dependent biphasic manner, with maximum levels at 6 and 48 h. The receptor protein, measured by [ 125I]GH binding, showed a time-delayed increase compared with the GHR mRNA changes. Pretreatment with naloxone inhibited the action of morphine, suggesting involvement of classical opioid receptors. The present study demonstrates, for the first time, effects of morphine on GHR mRNA levels and [ 125I]GH binding in human cultured lymphocytes.

An intraventricular infusion model for inducing morphine dependence in rats: quantitative assessment of precipitated withdrawal.

An experimental model of morphine dependence, in which rats were made dependent upon morphine by intraventricular infusion, is described. Morphine dependence was assessed and quantified by a series of withdrawal signs that were induced by the intraperitoneal administration of the morphine antagonist naloxone. The infusion of different concentrations of morphine resulted in the production of physical dependence, the severity of which was directly correlated with the concentration of morphine infused. A weak to moderate degree of dependence characterized by such withdrawal signs as teeth chattering, whole-body shakes, and vocalization was produced by infusions of morphine less than 5 micrograms/hr. A strong degree of physical dependence characterized by additional dominant withdrawal signs such as jumping and launching was produced by the infusion of 50 micrograms/hr morphine. The morphine pellet model that most closely approximated this degree of dependence was a three-pellet model in which a single 75-mg morphine pellet was implanted at 48-hr intervals. Abstinence precipitated by removal of the morphine-containing osmotic minipumps was characterized primarily by teeth chattering and whole-body shakes which persisted for at least 48 hr.