Lithium reverses the effect of opioids on eNOS/nitric oxide pathway in human umbilical vein endothelial cells

Lithium and Erectile Dysfunction: An Overview

Lithium has been a mainstay of therapy for patients with bipolar disorders for several decades. However, it may exert a variety of adverse effects that can affect patients' compliance. Sexual and erectile dysfunction has been reported in several studies by patients who take lithium as monotherapy or combined with other psychotherapeutic agents. The exact mechanisms underlying such side effects of lithium are not completely understood. It seems that both central and peripheral mechanisms are involved in the lithium-related sexual dysfunction. Here, we had an overview of the epidemiology of lithium-related sexual and erectile dysfunction in previous clinical studies as well as possible pathologic pathways that could be involved in this adverse effect of lithium based on the previous preclinical studies. Understanding such mechanisms could potentially open a new avenue for therapies that can overcome lithium-related sexual dysfunction and improve patients' adherence to the medication intake.

GSK3β Activity in Reward Circuit Functioning and Addiction

Glycogen synthase kinase-3β (GSK3β), primarily described as a regulator of glycogen metabolism, is a molecular hub linking numerous signaling pathways and regulates many cellular processes like cytoskeletal rearrangement, cell migration, apoptosis, and proliferation. In neurons, the kinase is engaged in molecular events related to the strengthening and weakening of synapses, which is a subcellular manifestation of neuroplasticity. Dysregulation of GSK3β activity has been reported in many neuropsychiatric conditions, like schizophrenia, major depressive disorder, bipolar disorder, and Alzheimer’s disease. In this review, we describe the kinase action in reward circuit-related structures in health and disease. The effect of pharmaceuticals used in the treatment of addiction in the context of GSK3β activity is also discussed.

Morphine dependence and withdrawal-induced changes in mouse Sertoli cell (TM4) line: Evaluation of apoptotic, inflammatory and oxidative stress biomarkers

Chronic morphine exerts deleterious effects on testicular function through either suppression of germ cells or somatic including Sertoli cells, probably through the activation of inflammatory, oxidative, and apoptosis biomarkers. Thus, the present study aimed to investigate whether the damaging effects of morphine dependence were reversed by the spontaneous morphine withdrawal or incubation with methadone and/or naloxone in Sertoli (TM4) cells using an in- vitro cell model of morphine dependence. Morphine dependence in TM4 cells was induced by increasing daily doses of morphine for 10 days and then maintained for two weeks in 5 μM. The cAMP levels were measured for an evaluation of morphine dependence. The cell viability and inflammatory, oxidative, apoptosis biomarkers, and glial cell-derived neurotrophic factor (GDNF) were measured after the end of treatment following the incubation of cells with methadone and naloxone and spontaneous withdrawal from morphine. We found that morphine dependence decreased cell viability, GDNF level and increased the levels of pro-oxidant, pro-inflammatory, and apoptotic biomarkers in TM4 cells, while spontaneous withdrawal from morphine and by naloxone decreased the levels of the biomarkers of pro-inflammatory and apoptotic in TM4 cells. Also, despite the low levels of pro-inflammatory factors following morphine withdrawal by methadone, it increased the cleaved/pro-caspase3 ratio in TM4 cells. This study showed that morphine dependence increased apoptosis probably via oxidative stress and inflammation pathways in TM4 cells. Also, it seems likely that spontaneous and naloxone withdrawal have beneficial consequences in the treatment of morphine dependence than methadone therapy, although they may require longer incubation periods.

The Expression and Function of Nitric Oxide Synthase Enzyme in Atorvastatin Effects on Morphine-Induced Dependence in Mice

Background: Atorvastatin exerts neuroprotective effects on the treatment of central nervous system disorders. Morphine analgesic tolerance and dependence remain as major concerns in medicine. Nitric oxide (NO) pathway mediates the development of opioid analgesic tolerance and dependence, as well as atorvastatin neuroprotection. Objectives: The present study aimed to assess the possible involvement of the NO/cGMP pathway in the process of the effects of atorvastatin on morphine physical dependence. Methods: Dependence was induced by repetitive injection of morphine sulfate. Naloxone was injected at the dose of 4 mg/kg on the last day of the experiment to assess withdrawal signs. Animals received atorvastatin (1, 5, 10, and 20 mg/kg, orally). Nitric oxide synthase (NOS) inhibitors and ODQ were injected before protective dose of atorvastatin. The gene expression of NOS isoforms was evaluated by real-time PCR. Thereafter, the hippocampal levels of cGMP and nitrite were measured. Results: Treatment with atorvastatin 10 mg/kg significantly attenuated naloxone-induced withdrawal behaviours. The administration of L-NAME, aminoguanidine, and ODQ before atorvastatin enhanced its effects. The treatment with atorvastatin significantly decreased the nitrite and cGMP levels as well as NOS gene expression in the hippocampus of dependent animals. Conclusions: It can be concluded that atorvastatin, possibly, through inducible NOS, could alleviate morphine dependence and withdrawal signs.