Search Results (85)

Objectives: The incidence of postoperative pain in patients that undergo spinal interventions is significantly increased, affecting their functional outcomes and quality of life. Dexmedetomidine (DEX) belongs to the category of centrally acting nonopioid agents with highly selective α2 adrenoreceptor agonist activity that are frequently applied in spinal surgery based on its antinociceptive and anxiolytic properties. Although many studies displayed the effectiveness of DEX in postoperative pain management, the impact of DEX on functional improvement after spinal surgeries is still debatable. Purpose: This systematic review focuses on the intraoperative and postoperative role of dexmedetomidine (DEX) as an analgesic agent in elective and emergency adult spine surgery. Methods: An electronic literature review search was conducted via Web of Science and PubMed to assess the impact of DEX on postoperative pain management, postoperative delirium (POD), and postoperative cognitive dysfunction (POCD). Discussion: Twenty-one studies were retrieved, three of which were review articles. The effects of DEX were studied for up to 48 h postoperatively. In most cases, its administration was associated with reduced intraoperative and postoperative opioid consumption. However, findings on pain control were less conclusive due to heterogeneity in dosing protocols, concomitant medications, the timing of administration, and pain scoring systems. DEX appears to reduce the incidence of POD and POCD, particularly when used in combination with other drugs. Conclusions: Although the present study supports that the intraoperative administration of dexmedetomidine decreases the pain intensity and/or opioid consumption as well as the development of POD and POCD in patients undergoing spinal surgeries during the first 24 h postoperatively, the current literature should be expanded to allow for the safe generalisation of findings over longer follow-up periods. Further research into the neuroprotective, analgesic, and anti-inflammatory roles of DEX is warranted. Full article

Severe kinds of uterine inflammation in animals cause reproductive and economic problems. Although there are changes in prostaglandin (PG) production and noradrenergic uterine innervation during endometritis, the role of noradrenaline (NA) and adrenoreceptors (ARs) in PGF2α formation is not yet fully understood. To recognize noradrenergic control of the PGF2α generation on the cellular level during endometritis, the action of NA as well as α1-, α2- and β-ARs on protein abundances of PGF synthase (PGFS) and PG 9-ketoreductase/carbonyl reductase (CBR1) in the Escherichia coli lipopolysaccharide (LPS)-influenced pig endometrial epithelial cells and PGF2α release from these cells were studied. The epithelial cells were exposed to LPS and NA alone; LPS with NA; LPS with agonists of α1-, α2- and β-Ars; LPS with antagonists of β1-, β2- and β3-ARs with NA; and LPS with antagonists of β1-, β2- and β3-ARs in combinations with agonists of β1-, β2-, and β3-ARs for 24 h. PGFS and CBR1 protein abundances in cells were determined by Western blotting and PGF2α medium content by ELISA. LPS alone increased CBR1 protein abundance and PGF2α release by epithelial cells in reference to the control value. NA alone exerted a stimulatory effect on PGFS and CBR1 protein abundances and PGF2α secretion. After the exposure of cells to LPS with NA together, CBR1 protein abundance, as well as PGF2α release, was higher than in response to LPS and NA alone. PGFS protein abundance was increased by LPS with NA together compared to LPS action alone. In LPS-exposed endometrial epithelial cells, NA acting by β2- and β3-ARs leads to a rise in CBR1 protein abundance and PGF2α secretion. β2-ARs also participate in the NA excitatory effect on PGFS protein abundance. The NA effect on all the parameters tested is not mediated by α1- and α2-ARs. β2- and β3-ARs mediate the stimulatory effect of NA on PGF2α generation and secretion by the LPS-exposed pig endometrial epithelial cells. The results suggest that these cells may be a significant source of PGF2α under noradrenergic stimulation in the inflamed endometrium, and NA affects processes controlled by PGF2α during endometritis in an indirect manner. Full article

Backgrounds: Approximately 18 million individuals were diagnosed with cancer in 2018. The rate is predicted to exceed 22 million by 2030. Radiotherapy is an essential part of cancer therapy, with well documented local and systemic side effects, including oxidative stress and apoptosis. Kidney tissues are also exposed to the deleterious effects of radiotherapy, resulting in acute or chronic kidney function impairment. This study compared the effects of the potent selective α2-adrenoreceptor agonist dexmedetomidine and amifostine on oxidative stress and apoptosis in kidney damage induced by x-irradiation in rats. Methods: Forty Sprague Dawley rats were assigned into five groups: control, x-irradiation, x-irradiation + amifostine, x-irradiation + dexmedetomidine 100 µg/kg, and X-ray irradiation + dexmedetomidine 200 µg/kg. Results: Necrotic tubules and degenerative Bowman’s capsules were present in the x-irradiation group. An increase was determined in malondialdehyde (MDA), Cleaved Caspase-3, and 8-OHdG levels compared to the control group (p ≤ 0.05). In contrast, there was a decrease in necrotic tubules, degenerative Bowman’s capsules, and the levels of MDA, Cleaved Caspase-3, and 8-OHdG in the amifostine and dexmedetomidine 100 µg/kg and 200 µg/kg treatment groups (p ≤ 0.05). Conclusions: Alpha 2 adrenergic receptor agonists exhibit protective effects against kidney injury induced in association with x-irradiation by reducing oxidative stress and apoptosis. Full article

Background/Objectives: A systematic review was conducted to compile all the evidence on the impact of ADRB1 and ADRB2 genetic variants on the response to β-blockers, used for the management of cardiovascular diseases. Methods: After searching in PubMed, PharmGKB, and the Cochrane Central Register of Controlled Trials including terms related to these drugs, genes, and pathologies, 1182 articles were retrieved, 29 of which met the inclusion criteria. A β-adrenoreceptor (ADRB) blockade qualitative variable was inferred for all the associations between genetic variants and clinical phenotypes. Results: The relationship between ADRB1 rs1801253 (G>C) C allele and higher receptor blockade showed a moderate overall level of evidence, reaching a high level on its relationship with higher reduction in the systolic (SBP) and diastolic blood pressure and heart rate (HR). The relationship between ADRB1 rs1801252 (A>G) G allele and lower receptor blockade reached an overall high level of evidence, considering its impact on the reduction in the SBP, HR, left ventricular end-diastolic diameter, and incidence of major cardiovascular events. The relationship between ADRB2 rs1042714 (G>C) C allele and lower receptor blockade reached a moderate overall level of evidence due to its impact on HR, pulmonary wedge pressure, and left ventricular ejection fraction response. The ADRB2 rs1042713 (G>A) A allele was associated with higher receptor blockade and higher HR reduction with a low level of evidence. Conclusions: The genotyping of both ADRB1 variants may be clinically useful; further investigation is required on the relevance of both ADRB2 variants. Further research is warranted to determine the clinical usefulness of ADRB preemptive genotyping. Full article

Background/Objectives: Complex regional pain syndrome (CRPS) is characterized by severe pain and reduced functionality, which can significantly affect an individual’s quality of life. The current treatment of CRPS is challenging. However, recent advances in diagnostic and treatment methods show promise for improving patient outcomes. This review aims to place the question of CRPS in a broader context and highlight the objectives of the research for future directions in the management of CRPS. Methods: This study involved a comprehensive literature review. Results: Research has identified three primary pathophysiological pathways that may explain the clinical variability observed in CRPS: inflammatory mechanisms, vasomotor dysfunction, and maladaptive neuroplasticity. Investigations into these pathways have spurred the development of novel diagnostic and treatment strategies focused on N-Methyl-D-aspartate Receptor Antagonists (NMDA), Toll-like receptor 4 (TLR-4), α1 and α2 adrenoreceptors, as well as the identification of microRNA (miRNA) biomarkers. Treatment methods being explored include immune and glial-modulating agents, intravenous immunoglobulin (IVIG) therapy, plasma exchange therapy, and neuromodulation techniques. Additionally, there is ongoing debate regarding the efficacy of other treatments, such as free radical scavengers, alpha-lipoic acid (ALA), dimethyl fumarate (DMF), adenosine monophosphate-activated protein kinase (AMPK) activators such as metformin, and phosphodiesterase-5 inhibitors such as tadalafil. Conclusions: The controversies surrounding the mechanisms, diagnosis, and treatment of CRPS have prompted researchers to investigate new approaches aimed at enhancing understanding and management of the condition, with the goal of alleviating symptoms and reducing associated disabilities. Full article

There is increasing evidence that β1-adrenoreceptor autoantibody (β1AR-AAb) elimination can break the vicious circle induced by certain pathological conditions associated with alteration of the physiological self-tolerance, followed by generation of such AAbs and activation of cell-mediated immune processes directed against the myocardium. Concerning this, the present narrative review article provides an updated overview of the state of knowledge about the role of auto-immunity in the etiopathogenesis of cardiomyopathies, with a particular focus on immunoadsorption (IA) therapy for β1AR-AAb-positive adult patients with a dilated cardiomyopathy (DCM)-associated refractory heart failure (HF). Among many relevant findings, the increasing prevalence (up to 97%) of β1AR-AAb-positive patients related to the aggravation of HF, the high prevalence (between 84% and 91%) of HF patients in which IA can reduce to a minimum any increased β1AR-AAb level, as well as the high prevalence (about 80%) of responders to the IA-induced normalization of β1AR-AAb levels by long-term improvement in LV ejection fraction with increase in LV stroke volume and cardiac output, are of particular relevance. Given that after the elimination of β1AR-AAbs in potential candidates for heart transplantation (HTx), the post-IA 3- and 5-year HTx-/mechanical support-free survival probability reached 80% and 63-69%, respectively, the good tolerability of IA and the possibility to repeat that therapy also in elderly persons strongly suggest that in appropriately selected patients, this therapy deserves much more attention in the future. Full article

Anthracyclines are a class of chemotherapeutics commonly used to treat a range of cancers. Despite success in improving cancer survival rates, anthracyclines have dose-limiting cardiotoxicity that prevents more widespread clinical utility. Currently, the therapeutic options for these patients are limited to the iron-chelating agent dexrazoxane, the only FDA-approved drug for anthracycline cardiotoxicity. However, the clinical use of dexrazoxane has failed to replicate expectations from preclinical studies. A limited list of GPCRs have been identified as pathogenic in anthracycline-induced cardiotoxicity, including receptors (frizzled, adrenoreceptors, angiotensin II receptors) previously implicated in cardiac remodeling in other pathologies. The RNA sequencing of iPSC-derived cardiac myocytes from patients has increased our understanding of the pathogenic mechanisms driving cardiotoxicity. These data identified changes in the expression of novel GPCRs, heterotrimeric G proteins, and the regulatory pathways that govern downstream signaling. This review will capitalize on insights from these experiments to explain aspects of disease pathogenesis and cardiac remodeling. These data provide a cornucopia of possible unexplored potential pathways by which we can reduce the cardiotoxic side effects, without compromising the anti-cancer effects, of doxorubicin and provide new therapeutic options to improve the recovery and quality of life for patients undergoing chemotherapy. Full article

Background: Clonidine has been used in clinical medicine, e.g., to treat high blood pressure and other conditions. Animal studies have linked its use to impairments of male reproductive functions, and although only a few reports exist for the human species, such actions may exist in man as well. The underlying reasons and, specifically, possible actions of clonidine at the level of the testis are not known. Introduction: Clonidine is an agonist at the α_2A-adrenoceptor (ADRA2A), which, as data bank mining indicated, is expressed by several cells of the human testis. The human testis and most of its cells are, however, not readily accessible to experimental testing. Cells from the peritubular wall compartment (human testicular peritubular cells; HTPCs) are the exception. Methods and Results: As shown by immunohistochemical/immunocytochemical and PCR techniques these cells express ADRA2A and retain expression upon isolation and culture. When tested over a concentration range (1–1000 µM) and 24 h, clonidine did not visibly affect HTPC morphology but significantly stimulated IL6 mRNA levels in a concentration-dependent manner. ELISA measurements of cell culture supernatants confirmed a stimulatory action of clonidine (10 µM) on secreted IL6. When examined in collagen gel contraction assays of HTPCs, clonidine (10 µM) exerted a slight relaxing action, while a proteomic study revealed that clonidine (10 µM) did not significantly change cellular protein abundance of HTPCs after 24 h (data available via ProteomeXchange with identifier PXD052220). Conclusion: Thus, ADRA2A-bearing cells in the human testis are targets for catecholamines and drugs such as clonidine. The results of this HTPCs-focused study only show the tip of the iceberg. It is likely that catecholamines/catecholaminergic drugs have the potential to interfere with human testicular functions. Full article

Organogenesis occurs in the uterus under low oxygen levels (4%). Preterm birth exposes immature newborns to a hyperoxic environment, which can induce a massive production of reactive oxygen species and potentially affect organ development, leading to diseases such as necrotizing enterocolitis. The β3-adrenoreceptor (β3-AR) has an oxygen-dependent regulatory mechanism, and its activation exerts an antioxidant effect. To test the hypothesis that β3-AR could protect postnatal ileal development from the negative impact of high oxygen levels, Sprague–Dawley rat pups were raised under normoxia (21%) or hyperoxia (85%) for the first 2 weeks after birth and treated or not with BRL37344, a selective β3-AR agonist, at 1, 3, or 6 mg/kg. Hyperoxia alters ileal mucosal morphology, leading to increased cell lipid oxidation byproducts, reduced presence of β3-AR-positive resident cells, decreased junctional protein expression, disrupted brush border, mucin over-production, and impaired vascularization. Treatment with 3 mg/kg of BRL37344 prevented these alterations, although not completely, while the lower 1 mg/kg dose was ineffective, and the higher 6 mg/kg dose was toxic. Our findings indicate the potential of β3-AR agonism as a new therapeutic approach to counteract the hyperoxia-induced ileal alterations and, more generally, the disorders of prematurity related to supra-physiologic oxygen exposure. Full article

Endometritis is a common disease in animals, leading to disruption of reproductive processes and economic losses. Noradrenergic control of prostaglandin (PG)I2 formation by inflamed endometrium is unknown. We determined the involvement of α1-, α2- and β-adrenoreceptors (ARs) in noradrenaline-influenced PGI synthase (PGIS) protein abundance and PGI2 release from porcine (1) endometrial explants with Escherichia coli (E. coli)-induced inflammation in vivo, and (2) E. coli lipopolysaccharide (LPS)-treated endometrial epithelial cells. Experiment 1. E. coli suspension (E. coli group) or saline (CON group) was injected into the uterine horns. In both groups, noradrenaline increased endometrial PGIS abundance and PGI2 release versus the control values, and it was higher in the E. coli group than in the CON group. In the CON group, a noradrenaline stimulating effect on both parameters takes place through α1D-, α2C- and β2-ARs. In the E. coli group, noradrenaline increased PGIS abundance and PGI2 release via α1A-, α2(B,C)- and β(1,2)-ARs, and PGI2 release also by α2A-ARs. Experiment 2. LPS and noradrenaline augmented the examined parameters in endometrial epithelial cells versus the control value. In LPS-treated cells, β(1,2)-ARs mediate in noradrenaline excitatory action on PGIS protein abundance and PGI2 release. β3-ARs also contribute to PGI2 release. Under inflammatory conditions, noradrenaline via ARs increases PGI2 synthesis and release from the porcine endometrium, including epithelial cells. Our findings suggest that noradrenaline may indirectly affect processes regulated by PGI2 in the inflamed uterus. Full article

Formoterol, a β2-adrenergic receptor (β2AR) agonist, shows promise in various diseases, but its effectiveness in Parkinson’s disease (PD) is debated, with unclear regulation of mitochondrial homeostasis. This study employed a cell model featuring mitochondrial ubiquinol-cytochrome c reductase core protein 1 (UQCRC1) variants associated with familial parkinsonism, demonstrating mitochondrial dysfunction and dynamic imbalance, exploring the therapeutic effects and underlying mechanisms of formoterol. Results revealed that 24-h formoterol treatment enhanced cell proliferation, viability, and neuroprotection against oxidative stress. Mitochondrial function, encompassing DNA copy number, repatriation, and complex III-linked respiration, was comprehensively restored, along with the dynamic rebalance of fusion/fission events. Formoterol reduced extensive hypertubulation, in contrast to mitophagy, by significantly upregulating protein Drp-1, in contrast to fusion protein Mfn2, mitophagy-related protein Parkin. The upstream mechanism involved the restoration of ERK signaling and the inhibition of Akt overactivity, contingent on the activation of β2-adrenergic receptors. Formoterol additionally aided in segregating healthy mitochondria for distribution and transport, therefore normalizing mitochondrial arrangement in mutant cells. This study provides preliminary evidence that formoterol offers neuroprotection, acting as a mitochondrial dynamic balance regulator, making it a promising therapeutic candidate for PD. Full article

During their lifetime, sheep undergo many painful husbandry and disease processes. Procedures undertaken on the farm, such as tail docking, castration, and mulesing, all cause considerable pain. In addition, sheep may experience painful diseases and injuries that require treatment by veterinary practitioners, and in biomedical research, sheep may undergo painful experimental procedures or conditions. It is important due to ethics, animal welfare, social licence, and, at times, legal requirements for farmers, veterinary practitioners, and researchers to provide pain relief for animals in their care. While there is a heightened awareness of and a greater interest in animal welfare, there remain few licensed and known analgesia options for sheep within Australia. A literature review was undertaken to identify currently known and potential future options for analgesic agents in sheep in farm and biomedical settings. Non-steroidal anti-inflammatories, opioids, local anaesthetics, α₂ adrenoreceptor agonists, and NMDA receptor antagonists are some of the more common classes of analgesic drugs referred to in the literature, but few drugs are registered for use in sheep, with even fewer proven to be effective. Only six analgesic product formulations, namely, lignocaine (e.g., Numocaine^®), Tri-Solfen^®, ketamine, xylazine, and meloxicam (oral transmucosal and injectable formulations), are currently registered in Australia and known to be efficacious in some types of painful conditions in sheep. The gap in knowledge and availability of analgesia in sheep can pose risks to animal welfare, social licence, and research outcomes. This article presents a summary of analgesic agents that have been used in sheep on farms and in clinical veterinary and biomedical research settings along with details on whether their efficacy was assessed, doses, routes of administration, indication for use, and pain assessment techniques (if any) used. The outcome of this research highlights the challenges, gaps, and opportunities for better analgesia options in sheep. Full article

Centhaquine is a novel vasopressor acting on α2A- and α2B-adrenoreceptors, increasing venous return and improving tissue perfusion. We investigated the effects of centhaquine on blood coagulation in normal state and uncontrolled hemorrhage using ex vivo and in vivo experiments in different species. Thromboelastography (TEG) parameters included clotting time (R), clot kinetics [K and angle (α)], clot strength (MA), and percent lysis 30 min post-MA (LY30). In normal rat blood, centhaquine did not alter R, K, α, MA, or LY30 values of the normal vehicle group or the antithrombotic effects of aspirin and heparin. Subsequently, New Zealand white rabbits with uncontrolled hemorrhage were assigned to three resuscitation groups: Sal-MAP 45 group (normal saline to maintain a mean arterial pressure, MAP, of 45 mmHg), Centh-MAP 45 group (0.05 mg kg⁻¹ centhaquine plus normal saline to maintain a MAP of 45 mmHg), and Sal-MAP 60 group (normal saline to maintain a MAP of 60 mmHg). The Sal-MAP 45 group was characterized by no change in R, reduced K and MA, and increased α. In the Centh-MAP 45 group, TEG showed no change in R, K, and α compared to saline; however, MA increased significantly (p = 0.018). In the Sal-MAP 60 group, TEG showed no change in R, an increase in α (p < 0.001), a decrease in K (p < 0.01), and a decrease in MA (p = 0.029) compared to the Centh-MAP 45 group. In conclusion, centhaquine does not impair coagulation and facilitates hemostatic resuscitation. Full article

(1) Background: The aim of our study was to assess the involvement of the sympathetic nervous system in the progression of patients with gastric carcinoma by analyzing the sympathetic neuronal fibers and beta 2 adrenoreceptors. (2) Methods: We performed a retrospective study in which we analyzed the clinical, biological, and histological data from a total of 104 patients diagnosed with stomach cancer. (3) Results: After analyzing the immunoreactivity of beta 2 adrenoreceptors, we observed increased values in patients with tumors larger than 5 cm in diameter (p = 0.0371), with a deeper degree of tumor invasion T3–4 (p = 0.0159), invasion in more than two lymph nodes (p = 0.0462), or a TNM stage III–IV. Regarding the survival analysis, better survival rates (65%) were observed for patients with a low value of beta 2 adrenoreceptors (B2A−), compared to B2A (+) patients, in which survival at 3 years of follow-up was only 43%. In addition, the analysis of intra-tumoral sympathetic fibers showed a better survival rate (83%) for patients with a low value of density compared to patients with increased density, in whom the survival rate was only 24%. (4) Conclusions: The findings of this study indicate that patients with stomach cancer have a more unfavorable prognosis when they have a higher density of sympathetic nerve fibers and an increased expression of beta 2 adrenergic receptors inside the tumor. Full article

In order to determine the behavior of the right ventricle, we have reviewed the existing literature in the area of cardiac remodeling, signal transduction pathways, subcellular mechanisms, β-adrenoreceptor-adenylyl cyclase system and myocardial catecholamine content during the development of left ventricular failure due to myocardial infarction. The right ventricle exhibited adaptive cardiac hypertrophy due to increases in different signal transduction pathways involving the activation of protein kinase C, phospholipase C and protein kinase A systems by elevated levels of vasoactive hormones such as catecholamines and angiotensin II in the circulation at early and moderate stages of heart failure. An increase in the sarcoplasmic reticulum Ca²⁺ transport without any changes in myofibrillar Ca²⁺-stimulated ATPase was observed in the right ventricle at early and moderate stages of heart failure. On the other hand, the right ventricle showed maladaptive cardiac hypertrophy at the severe stages of heart failure due to myocardial infarction. The upregulation and downregulation of β-adrenoreceptor-mediated signal transduction pathways were observed in the right ventricle at moderate and late stages of heart failure, respectively. The catalytic activity of adenylate cyclase, as well as the regulation of this enzyme by G_s proteins, were seen to be augmented in the hypertrophied right ventricle at early, moderate and severe stages of heart failure. Furthermore, catecholamine stores and catecholamine uptake in the right ventricle were also affected as a consequence of changes in the sympathetic nervous system at different stages of heart failure. It is suggested that the hypertrophied right ventricle may serve as a compensatory mechanism to the left ventricle during the development of early and moderate stages of heart failure. Full article