Sedation and general anaesthesia of crocodilians: a systematic review.

Sedation and general anaesthesia of crocodilians pose unique challenges due to their aggressive nature, poikilothermic physiology, and specific anatomical and physiological characteristics, all factors that complicate crocodilian anaesthesia. This review aimed to systematically review the literature regarding sedation and general anaesthesia of crocodilians with focus on efficacy and impact on vital parameters. A systematic literature search was performed according to PRISMA guidelines on May 2, 2023 in the databases Embase, PubMed, Scopus and Web of Science. Publications were excluded based on predefined exclusion criteria, which encompassed non-standard publications and publications unrelated to crocodilians, with fewer than five animals and/or with insufficient data on sedation and general anaesthesia. Five key factors were used to evaluate the strength of evidence: number of included animals, study design, definition of recovery time, blinded assessment of recovery and conflict of interest. Ten publications were included in this systematic review. Drugs used included alpha-2-adrenoceptor agonists, dissociative anaesthetics, benzodiazepines, neuromuscular blocking agents, propofol, alfaxalone, and inhalant gasses. The studies included in total 55 Alligator mississippiensis, 110 Crocodylus porosus, 15 Crocodylus johnstoni, and 15 Crocodylus niloticus. Factors such as temperature, administration route, dose, species, and age influenced protocols for sedation and general anaesthesia of crocodilians. The studies included used five different study designs. Only one study included a control group, done on retrospectively collected data. Blinded recovery assessments and declarations of no conflict of interest were noted in some studies. The use of four distinct recovery definitions posed challenges to comparability in this systematic review. The studies reported that medetomidine provided stable and reversible sedation, although it depressed heart rate. Alfaxalone was less stable outside the optimal temperature range. Intubation and inhalation anaesthesia were effective, and adrenaline reduced the length of the recovery period. Overall, the review provides valuable insights for veterinarians, researchers, and wildlife professionals involved in sedation and general anaesthesia of the crocodilian species, however, the literature is limited, and further research is needed to improve evidence-based medical management.

Diminished nuclear-localized ß-adrenoceptor signalling activates YAP to promote kidney fibrosis in diabetic nephropathy.

BACKGROUND AND PURPOSE: Diabetic nephropathy (DN) is a leading cause of chronic kidney disease (CKD), which is characterized by mesangial matrix expansion that involves dysfunctional mesangial cells (MCs). However, the underlying mechanisms remain unclear. This study aims to delineate the spatiotemporal contribution of adrenergic signalling in diabetic kidney fibrosis to reveal potential therapeutic targets. EXPERIMENTAL APPROACH: A model of diabetic nephropathy was induced by in db/db mice. Gene expression in kidneys was profiled by RNA-seq analyses, western blot and immunostaining. Subcellular-localized fluorescence resonance energy transfer (FRET) biosensors determined adrenergic signalling microdomains in MCs. Effects of oral rolipram, a phosphodiesterase 4 (PDE4) inhibitor, on the model were measured. KEY RESULTS: Our model exhibited impaired kidney function with elevated expression of adrenergic and fibrotic genes, including Adrb1, PDEs, Acta2 and Tgfß. RNA-seq analysis revealed that MCs with dysregulated YAP pathway were crucial to the extracellular matrix secretion in kidneys from diabetic nephropathy patients. In cultured MCs, TGF-ß promoted profibrotic gene transcription, which was regulated by nuclear-localized ß-adrenoceptor signalling. Mechanistically, TGF-ß treatment diminished nuclear-specific cAMP signalling in MCs and reduced PKA-dependent phosphorylation of YAP, leading to its activation. In parallel, db/db mouse kidneys showed increased expressions of PDE4B and PDE4D. Treatment with oral rolipram alleviated kidney fibrosis in db/db mice. CONCLUSION AND IMPLICATIONS: Diabetic nephropathy impaired nuclear-localized ß1-adrenoceptor-cAMP signalling microdomain through upregulating PDE4 expression, promoting fibrosis in MCs via PKA dephosphorylation-dependent YAP activation. Our results suggest PDE4 inhibition as a promising strategy for alleviating kidney fibrosis in diabetic nephropathy.

Sacubitril/Valsartan Combination Partially Improves Cardiac Systolic, but Not Diastolic, Function through ß-AR Responsiveness in a Rat Model of Type 2 Diabetes.

Cardiovascular complications are the major cause of diabetes mellitus-related morbidity and mortality. Increased renin-angiotensin-aldosterone system activity and decreased ß-adrenergic receptor (ß-AR) responsiveness contribute to diabetic cardiac dysfunction. We evaluated the effect of sacubitril/valsartan (neprilysin inhibitor plus angiotensin receptor antagonist combination) and valsartan treatments on the diabetic cardiac function through ß-AR responsiveness and on protein expression of diastolic components. Six-week-old male Sprague Dawley rats were divided into control, diabetic, sacubitril/valsartan (68 mg/kg)-, and valsartan-treated (31 mg/kg) diabetic groups. Diabetes was induced by a high-fat diet plus low-dose streptozotocin (30 mg/kg, intraperitoneal). After 10 weeks of diabetes, rats were treated for 4 weeks. Systolic/diastolic function was assessed by in vivo echocardiography and pressure-volume loop analysis. ß-AR-mediated responsiveness was assessed by in vitro papillary muscle and Langendorff heart experiments. Protein expression of sarcoplasmic reticulum calcium ATPase2a, phospholamban, and phosphorylated phospholamban was determined by Western blot. Sacubitril/valsartan improved ejection fraction and fractional shortening to a similar extent as valsartan alone. None of the treatments affected in vivo diastolic parameters or the expression of related proteins. ß1-/ß2-AR-mediated responsiveness was partially restored in treated animals. ß3-AR-mediated cardiac relaxation (an indicator of diastolic function) responses were comparable among groups. The beneficial effect of sacubitril/valsartan on systolic function may be attributed to improved ß1-/ß2-AR responsiveness.

Reappraisal of the mechanism of cardiovascular responses to sympathomimetic amines in anaesthetised rats: dual α1-adrenoceptor and trace amine receptor mechanisms.

Established dogma is that sympathomimetic amines, including ß-phenylethylamine (PEA), increase blood pressure by releasing noradrenaline from sympathetic neurons. Recent evidence allowing longer contact with isolated immersed tissues indicates other mechanisms. The present study re-evaluates the mechanism of pressor responses to PEA in anaesthetised rats with longer exposure to infusions. Blood pressure and heart rate were monitored by cannulating a common carotid artery of anaesthetised male Sprague-Dawley rats. Drugs were administered by bolus doses or by 20-min infusions via a cannulated jugular vein. Increases in blood pressure by bolus doses of the α-adrenoceptor agonist, phenylephrine, were converted to depressor responses by prazosin and therefore α-adrenoceptor-mediated. Pressor responses to bolus doses of PEA were reduced. PEA infusions yielded four-phase responses: An initial increase in pressure (phase 1) blocked by prazosin was due to α-adrenoceptor vasoconstriction and a secondary fall in pressure (phase 2) due to vasodilatation by nitric oxide release. A later pressure increase (phase 3), further elevated after infusion stopped (phase 4), was not attenuated by prazosin and therefore non-adrenergic. This study showed for the first time that the sympathomimetic amine, ß-phenylethylamine, increases blood pressure by two mechanisms. The established indirect sympathomimetic mechanism applies to bolus dose administration. However, with prolonged exposure to infusions, an additional slow-onset sustained non-adrenergic blood pressure increase occurs, most likely mediated via trace amine-associated receptors (TAAR-1). This response will dominate with prolonged exposures in clinical practice. These results prompt a re-evaluation of established dogma on the indirect sympathomimetic mechanisms of these amines.

ß-Adrenoceptor Signaling Activation Improves Bladder Fibrosis by Inhibiting Extracellular Matrix Deposition of Bladder Outlet Obstruction.

BACKGROUND: Partial bladder outlet obstruction (pBOO) causes deposition of extracellular matrix (ECM), promotes bladder fibrosis, and decreases bladder compliance. METHODS: To investigate the effect of ß-adrenoceptor (ADRB) on the ECM deposition of pBOO rat model and explore its underlying mechanism, human bladder smooth muscle cells (hBSMCs) were exposed to the pathological hydrostatic pressure (100 cm H2O) for 6 h, reverse transcription-polymerase chain reaction (RT-PCR) and western blotting were employed. Then the rats of sham operation and pBOO model were treated with vehicle or ADRB agonists for 3 weeks, and the alterations of the bladder were observed via Masson staining and immunohistochemical analysis. RESULTS: 100 cm H2O hydrostatic pressure significantly upregulated the expression of collagen I (COL1), collagen III (COL3) and fibronectin (FN), and downregulated the expression of ADRB2 and ADRB3 of hBSMCs at 6 h. The agonists of ADRB2 and ADRB3, Formoterol and BRL 37344, decreased COL1 and FN expression of hBSMCs under 100 cm H2O for 6 h compared with the cells exposed to hydrostatic pressure only. As the classic downstream pathways of ADRB, the EPAC pathway inhibited COL1 and FN expression of hBSMCs via regulating SMAD3 and SMAD2 activities, respectively. In pBOO rats, Procaterol (ADRB2 agonist), and Mirabegron (ADRB3 agonist) inhibited the formation of collagen and decreased the expression of FN and COL1 in the bladders of pBOO rats. CONCLUSIONS: The bladder fibrosis of pBOO and deposition of hBSMCs ECM under hydrostatic pressure were regulated by ADRB2, and ADRB3 via EPAC/SMAD2/FN and EPAC/SMAD3/COL1 pathways, these findings pave an avenue for effective treatment of pBOO.

Target-specific affinity separation of the bioactive compounds from herbal extract using the spin column packed with the immobilized protein microspheres prior to LC-MS analysis.

Excellent pretreatments before instrumental analysis are critical for separation and determination of target compounds for discovery of new drugs from herb medicines. We developed a rapid and highly-selective method to separate the bioactive compounds from herbal extract using protein affinity-selection spin column, which was packed with the new sorbent materials from integrating the recombinant ß2-adrenoceptor (ß2-AR) directly out of cell lysates onto the surface of microspheres. Protein affinity-selection spin column was placed in a centrifugal tube, where after the non-specific binders were released to the filtrate under the operational centrifugation, the specific binders on the spin column were cleaned with a washing solvent for LC-MS analysis. The known agonists of ß2-AR were retained/released on protein affinity-selection spin column but not on control column, demonstrating the method with good recovery (79.4∼95.7 %) and high repeatability (RSD < 3.5 %). The adsorption features of three ligands on the spin column were described best by Prism saturation binding model, and the high-affinity binding and the large binding capacity of the spin column make it feasible to trap the trace analytes effectively. It was applied in separating bioactive compounds from Alstoniae Scholaris extract, two of which were identified as picrinine and oleanolic acid in combination with LC-MS and verified as the potential agonists towards ß2-AR though molecular docking and cell experiments. Our study demonstrated that, the spin column with the immobilized protein sorbents in the centrifugal filter device represents a promising tool, enabling rapid and target-specific affinity separation of the bioactive compounds from herbal extract.

Leveraging adrenergic receptor blockade for enhanced nonalcoholic fatty liver disease treatment via a biomimetic nanoplatform.

Nonalcoholic fatty liver disease (NAFLD) is characterized by excessive lipid accumulation, steatosis and fibrosis. Sympathetic nerves play a critical role in maintaining hepatic lipid homeostasis and regulating fibrotic progression through adrenergic receptors expressed by hepatocytes and hepatic stellate cells; however, the use of sympathetic nerve-focused strategies for the treatment of NAFLD is still in the infancy. Herein, a biomimetic nanoplatform with ROS-responsive and ROS-scavenging properties was developed for the codelivery of retinoic acid (RA) and the adrenoceptor antagonist labetalol (LA). The nanoplatform exhibited improved accumulation and sufficient drug release in the fibrotic liver, thereby achieving precise codelivery of drugs. Integration of adrenergic blockade effectively interrupted the vicious cycle of sympathetic nerves with hepatic stellate cells (HSCs) and hepatocytes, which not only combined with RA to restore HSCs to a quiescent state but also helped to reduce hepatic lipid accumulation. We demonstrated the excellent ability of the biomimetic nanoplatform to ameliorate liver inflammation, fibrosis and steatosis. Our work highlights the tremendous potential of a sympathetic nerve-focused strategy for the management of NAFLD and provides a promising nanoplatform for the treatment of NAFLD.

Indirect involvement of α2-adrenoceptors in the mechanical antihypersensitivity effect induced by the spinally administered imidazoline I1 receptor ligand LNP599 in a rat model of experimental neuropathy.

Here we assess whether neuropathic pain hypersensitivity is attenuated by spinal administration of the imidazoline I1-receptor agonist LNP599 and whether the attenuation involves co-activation of α2-adrenoceptors. Spared nerve injury (SNI) model of neuropathy was used to induce mechanical hypersensitivity in male and female rats with a chronic catheter for intrathecal drug administrations. Mechanical sensitivity and heat nociception were assessed behaviorally in the injured limb. Additionally, GTPγS radioligand binding assay, ß-arrestin recruitment and intracellular cAMP levels were used for receptor profiling in vitro. LNP599 (imidazoline I1 receptor agonist) and clonidine (α2-adrenoceptor agonist) produced equal dose-related mechanical antihypersensitivity effects in both sexes. LNP599 attenuated heat nociception preferentially in males, while clonidine reduced heat nociception equally in males and females. Carbophenyline (another imidazoline I1 receptor agonist) had no significant effect on mechanical hypersensitivity or heat nociception in males or females. Mechanical antihypersensitivity and heat antinociception induced by LNP599 in SNI males was prevented by pretreatments with yohimbine or atipamezole (two α2-adrenoceptor antagonists) but not by efaroxan (a mixed imidazoline I1 receptor/α2-adrenoceptor antagonist). In vitro assays indicated that LNP599 does not activate α2A- or other subtypes of α2-adrenoceptors. However, LNP599 was a weak partial agonist for 5-HT2B receptors and bound to sigma-1 and sigma-2 receptors that all are involved in modulation of spinal nociception. The results indicate that the suppression of neuropathic pain hypersensitivity by LNP599 is not due to action on spinal imidazoline I1 receptors, but rather due to indirect activation of spinal α2-adrenoceptors.

Carvedilol Activates a Myofilament Signaling Circuitry to Restore Cardiac Contractility in Heart Failure.

Phosphorylation of myofilament proteins critically regulates beat-to-beat cardiac contraction and is typically altered in heart failure (HF). ß-Adrenergic activation induces phosphorylation in numerous substrates at the myofilament. Nevertheless, how cardiac ß-adrenoceptors (ßARs) signal to the myofilament in healthy and diseased hearts remains poorly understood. The aim of this study was to uncover the spatiotemporal regulation of local ßAR signaling at the myofilament and thus identify a potential therapeutic target for HF. Phosphoproteomic analysis of substrate phosphorylation induced by different ßAR ligands in mouse hearts was performed. Genetically encoded biosensors were used to characterize cyclic adenosine and guanosine monophosphate signaling and the impacts on excitation-contraction coupling induced by ß1AR ligands at both the cardiomyocyte and whole-heart levels. Myofilament signaling circuitry was identified, including protein kinase G1 (PKG1)-dependent phosphorylation of myosin light chain kinase, myosin phosphatase target subunit 1, and myosin light chain at the myofilaments. The increased phosphorylation of myosin light chain enhances cardiac contractility, with a minimal increase in calcium (Ca2+) cycling. This myofilament signaling paradigm is promoted by carvedilol-induced ß1AR-nitric oxide synthetase 3 (NOS3)-dependent cyclic guanosine monophosphate signaling, drawing a parallel to the ß1AR-cyclic adenosine monophosphate-protein kinase A pathway. In patients with HF and a mouse HF model of myocardial infarction, increasing expression and association of NOS3 with ß1AR were observed. Stimulating ß1AR-NOS3-PKG1 signaling increased cardiac contraction in the mouse HF model. This research has characterized myofilament ß1AR-PKG1-dependent signaling circuitry to increase phosphorylation of myosin light chain and enhance cardiac contractility, with a minimal increase in Ca2+ cycling. The present findings raise the possibility of targeting this myofilament signaling circuitry for treatment of patients with HF.

Adventures with the ß2-adrenoceptor Receptor: A Career Long Interest in Agonising One of the Most Widely Studied GPCRs.

Drug discovery is a multi-disciplinary effort in which groups with expertise in a range of areas combine in a unified way to achieve a common goal: to deliver a clinical candidate to evaluate a hypothesis for improving human health. As a medicinal chemist this environment has provided multiple opportunities to be involved in cross-discipline interactions that have been both rewarding and led to outcomes that would not have been possible without an intimate interdisciplinary curiosity. Within this article I aim to share some of my experiences with the ß2-adrenoceptor that have fostered such synergistic relationships with several disciplines, but in particular with in vitro pharmacologists looking at different ways to stimulate this G protein-coupled receptor (GPCR). This interest now spans over a quarter of a century and has been intertwined with the delivery of three clinical candidates.

Intrinsic ADRB2 inhibition improves CAR-T cell therapy efficacy against prostate cancer.

Chimeric antigen receptor (CAR)-T cell therapy has shown limited success in patients with solid tumors. Recent in vitro and in vivo data have shown that adrenoceptor beta-2 (ADRB2) is a novel checkpoint receptor that inhibits T cell-mediated anti-tumor responses. To inhibit ADRB2-mediated inhibitory signaling, we downregulated ADRB2 in CAR-T (shß2-CAR-T) cells via RNA interference, assessed different parameters, and compared them with conventional second-generation CAR-T cells. ADRB2 knockdown CAR-T cells exhibited enhanced cytotoxicity against prostate cancer cell lines in vitro, by increasing CD69, CD107a, GzmB, IFN-γ, T-bet, and GLUT-1. In addition, ADRB2 deficiency led to improved proliferation, increased CD8/CD4 T cell ratio, and decreased apoptosis in CAR-T cells. shß2-CAR-T cells expressed more Bcl-2 and led to the generation of more significant proportions of T central memory cells. Finally, the ZAP-70/NF-κB signaling axis was shown to be responsible for the improved functions of novel CAR-T cells. In tumor-bearing mice, shß2-CAR-T cells performed better than conventional CAR-T cells in eradicating prostate tumors. The study provides the basis for future clinical and translational CAR-T cell research to focus on adrenergic stress-mediated challenges in the tumor microenvironment of stressed tumors.

ß-Adrenoceptor Agonists Attenuate Thrombin-Induced Impairment of Human Lung Endothelial Cell Barrier Function and Protect the Lung Vascular Barrier during Resuscitation from Hemorrhagic Shock.

ß-adrenoceptor (ß-AR) agonists are known to antagonize thrombin-induced impairment (TII) of bovine and ovine lung endothelial barrier function. The effects of adrenoceptor agonists and other vasoactive agents on human lung microvascular endothelial cell (HULEC-5a) barrier function upon thrombin exposure have not been studied. Furthermore, it is unknown whether the in vitro effects of adrenoceptor agonists translate to lung protective effects in vivo. We observed that epinephrine, norepinephrine, and phenylephrine enhanced normal and prevented TII of HULEC-5a barrier function. Arginine vasopressin and angiotensin II were ineffective. α1B-, α2A/B-, and ß1/2-ARs were detectable in HULEC-5a by RT-PCR. Propranolol but not doxazosin blocked the effects of all adrenoceptor agonists. Phenylephrine stimulated ß2-AR-mediated Gαs activation with 13-fold lower potency than epinephrine. The EC50 to inhibit TII of HULEC-5a barrier function was 1.8 ± 1.9 nM for epinephrine and >100 nM for phenylephrine. After hemorrhagic shock and fluid resuscitation in rats, Evans blue extravasation into the lung increased threefold (p < 0.01 vs. sham). Single low-dose (1.8 µg/kg) epinephrine administration at the beginning of resuscitation had no effects on blood pressure and reduced Evans blue extravasation by 60% (p < 0.05 vs. vehicle). Our findings confirm the effects of ß-adrenoceptor agonists in HULEC-5a and suggest that low-dose ß-adrenoceptor agonist treatment protects lung vascular barrier function after traumatic hemorrhagic shock.

Dynamic phenotypic shifts and M2 receptor downregulation in bladder smooth muscle cells induced by mirabegron.

Introduction: Mirabegron is available for treatment of overactive bladder (OAB). However, mechanisms underlying symptom improvements and long-term effects on bladder smooth muscle cells are uncertain. Contractility and growth of bladder smooth muscle contribute to OAB, and depend on smooth muscle phenotypes, and on muscarinic receptor expression. Here, we examined prolonged exposure to mirabegron (20-48 h) on phenotype markers, muscarinic receptor expression, and phenotype-dependent functions in human bladder smooth muscle cells (hBSMC). Methods: Expression of markers for contractile (calponin, MYH11) and proliferative (MYH10, vimentin) phenotypes, proliferation (Ki-67), and of muscarinic receptors were assessed by RT-PCR. Proliferation, viability, actin organization and contractions in cultured hBSMC were examined by EdU, CCK-8, phalloidin staining and matrix contraction assays. Results: Calponin-1 mRNA decreased with 100 nM and 150 nM mirabegron applied for 20 h (0.56-0.6 fold of controls). Decreases were resistant to the ß3-AR antagonist L-748,337 (0.34-0.55 fold, 100-150 nM, 20 h). After 40 h, decreases occured in the presence of L-748,337, but not without L-748,337. MYH11 mRNA increased with 150 nM mirabegron (40 h, 1.9 fold). This was partly preserved with L-748,337, but not observed after 20 h mirabegron exposure. Vimentin mRNA reduced with 150 nM mirabegron after 20 h, but not after 40 h, with and without L-748,337 (0.71-0.63 fold). MYH10 mRNA expression remained unaffected by mirabegron. Exposure to 150 nM mirabegron increased Ki-67 mRNA after 20 h in the presence of, but not without L-748,337, and after 40 h without, but not with L-748,337. Proliferation rates and actin organization were stable with 50-150 nM mirabegron (24 h, 48 h). Viability increased significantly after mirabegron exposure for 20 h, and by trend after 40 h, which was fully sensitive to L-748,337. M2 mRNA was reduced by 20 h mirabegron, which was resistant to L-748,337. Carbachol (3 µM) enhanced time-dependent contractions of hBSMC, which was inhibited by mirabegron (150 nM) in late phases (24 h), but not in early phases of contractions. Conclusion: Mirabegron induces dynamic phenotype alterations and M2 downregulation in hBSMC, which is paralleled by time-shifted anticontractile effects. Phenotype transitions may be involved in improvements of storage symptoms in OAB by mirabegron.

Cilostazol attenuates mirabegron-induced hepatic and renal toxicity in rats: regulation of metabolic, oxidative, and inflammatory pathways.

BACKGROUND: Mirabegron (MIRG) is a type of ß3 adrenoceptor agonist that is considered an alternative therapy for the treatment of overactive bladder (OAB) symptoms. Cilostazol (CITZ) is a selective inhibitor of phosphodiesterase (III) that has various pharmacological effects. OBJECTVE: The current study aimed to highlight the regulatory effects of CITZ on MIRG-induced toxicity. MATERIALS AND METHODS: Male rats were divided into six groups. Blood samples were collected to determine different hepatic and kidney function levels along with serum protein electrophoresis and inflammatory factor levels. Histopathological studies and oxidative stress (OS) were also assessed. Kidney and hepatic damage were detected following the administration of MIRG, especially at high doses, due to elevated OS, inflammation, and apoptotic marker levels. RESULTS: Rats receiving CITZ exhibited significant improvements in both hepatic and kidney functions, with decreased inflammation and OS. CONCLUSION: CITZ administration plays a beneficial role in alleviating hepatic and nephrotoxicity induced by MIRG by inhibiting OS and inflammation.

ß-Adrenoceptor blockade can augment the torsadogenic action of risperidone.

Risperidone is a second-generation antipsychotic for treating schizophrenia and bipolar disorder. It can potently inhibit IKr, but is classified into conditional risk for torsade de pointes (TdP) by CredibleMeds®. Our previous studies using chronic atrioventricular block dogs showed that risperidone alone did not induce TdP, and that dl-sotalol (ß-adrenoceptor blockade plus IKr inhibition) induced TdP three times more frequently than d-sotalol (IKr inhibition alone). Since risperidone can block α1-adrenoceptor and decrease blood pressure, the resulting reflex-mediated increase of sympathetic tone on ß-adrenoceptor might protect the heart from its IKr inhibition-associated TdP. To validate this hypothesis, risperidone was administered to chronic atrioventricular block dogs after ß-adrenoceptor blocker atenolol infusion with monitoring J-Tpeak and Tpeak-Tend, which are proarrhythmic surrogate markers of "substrate" and "trigger" toward TdP, respectively. Atenolol alone induced TdP in 1 out of 5 dogs; moreover, an additional infusion of risperidone induced TdP in 3 out of 4 dogs. Risperidone prolonged QT interval, J-Tpeak and Tpeak-Tend in animals that induced TdP. These findings indicate that ß-adrenoceptor blockade can diminish repolarization reserve to augment risperidone's torsadogenic potential, thus advising caution when using ß-adrenoceptor blockers in patients with IKr inhibition-linked labile repolarization.

ADRA2A promotes the classical/progenitor subtype and reduces disease aggressiveness of pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) manifests diverse molecular subtypes, including the classical/progenitor and basal-like/squamous subtypes, with the latter known for its aggressiveness. We employed integrative transcriptome and metabolome analyses to identify potential genes contributing to the molecular subtype differentiation and its metabolic features. Our comprehensive analysis revealed that adrenoceptor alpha 2A (ADRA2A) was downregulated in the basal-like/squamous subtype, suggesting its potential role as a candidate suppressor of this subtype. Reduced ADRA2A expression was significantly associated with a high frequency of lymph node metastasis, higher pathological grade, advanced disease stage, and decreased survival among PDAC patients. In vitro experiments demonstrated that ADRA2A transgene expression and ADRA2A agonist inhibited PDAC cell invasion. Additionally, ADRA2A-high condition downregulated the basal-like/squamous gene expression signature, while upregulating the classical/progenitor gene expression signature in our PDAC patient cohort and PDAC cell lines. Metabolome analysis conducted on the PDAC cohort and cell lines revealed that elevated ADRA2A levels were associated with suppressed amino acid and carnitine/acylcarnitine metabolism, which are characteristic metabolic profiles of the classical/progenitor subtype. Collectively, our findings suggest that heightened ADRA2A expression induces transcriptome and metabolome characteristics indicative of classical/progenitor subtype with decreased disease aggressiveness in PDAC patients. These observations introduce ADRA2A as a candidate for diagnostic and therapeutic targeting in PDAC.

Oxymetazoline as a predictor of turbinate reduction surgery outcomes: Objective support from a prospective, single-blinded, computational fluid dynamics study.

BACKGROUND: A patient's subjective response to topical nasal decongestant is often used to screen for turbinate reduction surgery suitability. However, this anecdotal strategy has not been objectively and quantitatively evaluated. METHODS: Prospective, longitudinal, and single-blinded cohort study employing computational fluid dynamic modeling based on computed tomography scans at baseline, 30 min postoxymetazoline, and 2 months postsurgery on 11 patients with chronic turbinate hypertrophy. RESULTS: Nasal obstruction symptom evaluation (NOSE) and visual analogue scale (VAS) obstruction scores significantly improved from baseline to postoxymetazoline and again to postsurgery (NOSE: 71.82 ± 14.19 to 42.27 ± 25.26 to 22.27 ± 21.04; VAS: 6.09 ± 2.41 to 4.14 ± 2.20 to 2.08 ± 1.56; each interaction p < 0.05), with significant correlation between the latter two states (r∼0.37-0.69, p < 0.05). Oxymetazoline had a broader anatomical impact throughout inferior and middle turbinates than surgery (many p < 0.05); however, the improvement in regional airflow is similar (most p > 0.05) and predominantly surrounding the inferior turbinate. Strong postoxymetazoline to postsurgery correlations were observed in decreased nasal resistance (r = 0.79, p < 0.05), increased regional airflow rates (r = -0.47 to -0.55, p < 0.05) and regional air/mucosa shear force and heat flux (r = 0.43 to 0.58, p < 0.05); however, only increasing peak heat flux significantly correlated to symptom score improvement (NOSE: r = 0.48, p < 0.05). CONCLUSION: We present the first objective evidence that the "topical decongestant test" can help predict turbinate reduction surgery outcomes. The predictive effect is driven by similar improvementin regional airflow that leading to improved air/mucosa stimulations (peak heat flux) rather than through reduced nasal resistance.

Functional autoantibodies against G protein-coupled receptors in hepatic and pulmonary hypertensions in human schistosomiasis.

Introduction: Schistosomiasis (SM) is a parasitic disease caused by Schistosoma mansoni. SM causes chronic inflammation induced by parasitic eggs, with collagen/fibrosis deposition in the granuloma process in the liver, spleen, central nervous system, kidneys, and lungs. Pulmonary arterial hypertension (PAH) is a clinical manifestation characterized by high pressure in the pulmonary circulation and right ventricular overload. This study investigated the production of functional autoantibodies (fAABs) against the second loop of the G-protein-coupled receptor (GPCR) in the presence of hepatic and PAH forms of human SM. Methods: Uninfected and infected individuals presenting acute and chronic manifestations (e.g., hepatointestinal, hepato-splenic without PAH, and hepato-splenic with PAH) of SM were clinically evaluated and their blood was collected to identify fAABs/GPCRs capable of recognizing endothelin 1, angiotensin II, and a-1 adrenergic receptor. Human serum was analyzed in rat cardiomyocytes cultured in the presence of the receptor antagonists urapidil, losartan, and BQ123. Results: The fAABs/GPCRs from chronic hepatic and PAH SM individuals, but not from acute SM individuals, recognized the three receptors. In the presence of the antagonists, there was a reduction in beating rate changes in cultured cardiomyocytes. In addition, binding sites on the extracellular domain functionality of fAABs were identified, and IgG1 and/or IgG3 antibodies were found to be related to fAABs. Conclusion: Our data suggest that fAABs against GPCR play an essential role in vascular activity in chronic SM (hepatic and PAH) and might be involved in the development of hypertensive forms of SM.

Protective Effects of Beta-3 Adrenoceptor Agonism on Mucosal Integrity in Hyperoxia-Induced Ileal Alterations.

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 ß3-adrenoreceptor (ß3-AR) has an oxygen-dependent regulatory mechanism, and its activation exerts an antioxidant effect. To test the hypothesis that ß3-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 ß3-AR agonist, at 1, 3, or 6 mg/kg. Hyperoxia alters ileal mucosal morphology, leading to increased cell lipid oxidation byproducts, reduced presence of ß3-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 ß3-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.