Dietetics, Nutrition and Biological Sciences
Permanent URI for this collectionhttps://eresearch.qmu.ac.uk/handle/20.500.12289/23
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Item The Roles of Opioid Receptors and Agonists in Health and Disease Conditions(Maxwell Scientific Organization,, 2011-04-30) Ibegbu, A. O.; Mullaney, I.; Fyfe, Lorna; McBean, DouglasOpioid receptors are found in the Central Nervous System (CNS) and are classified as mu (µ), kappa (κ), delta (δ) and sigma (σ) opioid receptors. Opioid receptors belong to the large family of G Protein Coupled Receptors (GPCRs), and have diverse and important physiological roles. The aim of the present review is to discuss the roles played by opioid receptors, their agonists and antagonists in health and disease conditions. Opioid receptors are not uniformly distributed in the CNS and are found in areas concerned with pain, with the highest concentration in the cerebral cortex, followed by the amygdala, septum, thalamus, hypothalamus, midbrain and spinal cord. Activated delta opioid receptors are coupled to Gi1 while activated mu opioid receptors are coupled to Gi3 in neuroblastoma cells. Mu opioid receptors are activated by mu receptor agonists and are coupled through the Gi1 and GoA. Both mu and kappa opioid receptors are coupled via both Gi and Gz and opioid receptors are important targets for thousands of pharmacological agents. GPCRs typically require activation by agonists for their signalling activity to be initiated but some of the GPCRs may display basal or spontaneous signalling activity in the absence of an agonist. The stimulation of these receptors triggers analgesic effects and affects the function of the nervous system, gastrointestinal tract and other body systems. Hundreds of analogs of opioid peptides have been synthesized in an effort to make the compounds more active, selective, and resistant to biodegradation than the endogenous ligands. All these modifications resulted in obtaining very selective agonists and antagonists with high affinity at mu-, delta-, and kappa-opioid receptors, which are useful in further studies on the pharmacology of opioid receptors in a mammalian organism.Item The Effects of Hypoxia and Opioid Receptor Agonists Treatment in Cortical B50 Neuronal Cells in Culture(Uludag University Applied Research Center for Agriculture (ARCA) and Applied Research Center for Environmental Problems (ARCEP), Uludag University Gorukle Campus, 16059 Bursa-Turkey, 2012-12) Ibegbu, A. O.; Fyfe, Lorna; McBean, Douglas; Mullaney, I.Hypoxia has been implicated in nerve cell deaths in many neurological disorders and opioid receptor agonists have some positive benefits on the nervous system. The aim of the present work was to investigate the effects of hypoxia and opioid receptor agonists' treatment on the morphology of B50 cells cultured in hypoxia using neuronal pattern and pattern formation as a case study. The B50 cells were cultured in normal incubator (21%O2; 5% CO2) as the control group and hypoxic incubator (5%O2; 5% CO2) as the experimental group and three opioid receptor agonists namely DAMGO (_), DSLET () and ICI-199,441 () were administered to the cells for 48 hours as treatment against hypoxia after 48 hours of culture at 10_M, 50_M and 100_M concentrations. Neuronal morphology and wellbeing was assessed using same field morphological assessment and lactate dehydrogenase leakage (LDH). The result showed groups of dead and degenerating B50 neuronal cells, altered neuronal pattern and pattern formation and some significant changes (P<0.05) in cellular levels of LDH leakage in normal, hypoxic cells and cells treated with different agonists. The changes in morphology, neuronal pattern and LDH release indicate that hypoxia induced morphological and cellular changes in B50 cells in hypoxia and opioid agonists have some potential benefits in the treatment of hypoxia-induced changes in B50 cells in culture.