Journal of pharmacological and toxicological methods最新文献

{"title":"Advancements in cardiovascular data analysis: PAROT - A novel GLP-compliant application for efficient telemetry and ECG data visualization and reporting","authors":"Corey R. Petrella","doi":"10.1016/j.vascn.2025.107773","DOIUrl":"10.1016/j.vascn.2025.107773","url":null,"abstract":"<div><div>Some of the challenges associated with the conduct of cardiovascular (CV) telemetry studies include the analysis, review, and management of large datasets that may be collected across different species (e.g., rat, dog, or NHP) using various study designs (e.g., cross-over or parallel). Many labs consequently face limitations such as lack of flexibility, control, and ease of GLP-compliant upgrades using either internal or off-the-shelf applications. In response to the ICH E14/S7B Q&amp;As and best practice recommendations along with internal demand for efficient data reporting and visualization tools for CV telemetry and surface lead ECG data analysis, we have developed a novel GLP-compliant application termed Ponemah Analysis and Reporting Output Tool (PAROT). The PAROT application is a web-based platform designed to address limitations in our existing analysis tools, enhancing CV data analysis by enabling users to analyze, visualize, and generate files to allow for statistical analysis and SEND reporting. PAROT integrates with other platforms such as Ponemah for data acquisition/analysis and SAS for statistical analysis (e.g., ANOVA) and reporting. This has led to efficiency gains in data review, interpretation, reporting and informed decision making. The purpose of this abstract is to highlight the development and application of PAROT while demonstrating some of its features using real-world exemplary data that facilitate data review consistent with ICH S7B Q&amp;As. These features include individual animal and group mean time course plots for all CV parameters, scatter plots of QT/QTc vs. HR/RR to evaluate heart rate correction methods, and statistical outputs showing least significant difference (LSD) and root mean square error (RMSE) values to demonstrate study sensitivity. Finally, the summary data can be exported to generate a file consistent with SEND. While this application is specific for internal use, it serves as a model for harmonizing data integrity, analysis, and compliance in CV studies. In summary, the PAROT application represents an enhancement in CV data review and visualization, while integrating current updates in regulatory guidance and enabling users to utilize their data effectively in drug safety and development.</div></div>","PeriodicalId":16767,"journal":{"name":"Journal of pharmacological and toxicological methods","volume":"135 ","pages":"Article 107773"},"PeriodicalIF":1.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145095370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reproducible safety pharmacology echocardiography studies in vehicle-treated canines and NHPs","authors":"Steve R. Roof,&nbsp;Sydney E. St Clair","doi":"10.1016/j.vascn.2025.107835","DOIUrl":"10.1016/j.vascn.2025.107835","url":null,"abstract":"<div><div>Echocardiography has emerged as a key component in cardiovascular diagnostics, offering a non-invasive, clinically relevant approach. Echocardiography enables the ability monitor disease progression, therapeutic responses, efficacy and safety of gene therapy interventions, as well as detecting cardiac toxicity. Typical measurements include the assessment of left ventricular (LV) systolic and diastolic function to evaluate overall cardiac performance, LV wall thickness/chamber size, evaluation of mitral and tricuspid regurgitation (MR/TR) to identify valvular defects, quantification of right ventricular performance (TAPSE and pulmonary velocities), left atrial annulus tissue doppler, as well as measurement of left atrial size/function to assess atrial performance. To determine the reproducibility and consistency of echocardiographic measurements, vehicle-treated animals were studied. Canines and non-human primates (NHPs) were sedated with butorphanol (0.2 mg/kg, IV) or ketamine (10 mg/kg, IM), respectively. In the canine study, echocardiographic measurements were collected in 4 animals at baseline and 6 h post vehicle (oral gavage). Of the 43 measured parameters, 40 were within 10 % of baseline. In the NHP study (<em>n</em> = 4), longitudinal vehicle data was collected at baseline, 6- and 12-weeks post intervention and demonstrated similar precision and reproducibility as all parameters were less than 15 % change from baseline at 6 weeks (32 out of 37 under 10 %). At 12 weeks, 35 of 37 were less than 15 % and 29 of 37 were under 10 %. In conclusion, incorporating high-quality and reproducible echocardiographic assessments into safety pharmacology studies offers a significant advantage by providing critical insights into cardiac function. However, the sonographer, ultrasound machine, and technique must be constant to detect a small difference in safety pharmacology studies.</div></div>","PeriodicalId":16767,"journal":{"name":"Journal of pharmacological and toxicological methods","volume":"135 ","pages":"Article 107835"},"PeriodicalIF":1.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145095354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emerging neurology safety biomarkers for advanced modality therapeutic-associated neurotoxicity in nonhuman primates","authors":"Catherine F. Ruff,&nbsp;Tanja S. Zabka,&nbsp;Tien Nguyen,&nbsp;Donna Lee","doi":"10.1016/j.vascn.2025.107838","DOIUrl":"10.1016/j.vascn.2025.107838","url":null,"abstract":"<div><div>There have been exciting advances in basic neuroscience research, yet the approval rate of novel therapeutics for neurodegenerative indications is low. In addition to poor efficacy, previously unidentified safety concerns in clinical trials are a major contributor to neurology drug attrition. Although there are regulatory-mandated safety assessments of the central nervous system in nonclinical studies, these are limited to neurofunctional tests, which are adequate for detecting overtly neurotoxic-mediated deficits, but more sensitive, specific, and quantitative methods are needed to advance the safety profiling of drug candidates early in nonclinical studies. Fluid-based biomarkers have emerged as a potential tool for improving neurotoxicity assessment, especially in life, across species. Here, we evaluated a subset of neurology biomarkers in a nonclinical toxicity study in nonhuman primates administered a single intrathecal dose of an advanced modality therapeutic molecule over an 8-week observation period. We show dose-dependent and time-dependent increases in total Tau, ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1, and to a lesser extent neurofilament light (NfL) in the cerebrospinal fluid, but less compelling responses in plasma. Elevations in these biomarkers correlated with even minor microscopic evidence of neuronal necrosis, yet clinical observations were not identified on neurofunctional tests. These results demonstrate that Tau, UCH-L1, and NfL are sensitive, specific, and quantitative biomarkers of advanced modality therapeutic-associated neurotoxicity early in nonclinical studies. Furthermore, these biomarkers have the potential to improve drug candidate screening for neurologic indications and create a therapeutic index for forward translation into the clinic for these potentially life-altering drugs.</div></div>","PeriodicalId":16767,"journal":{"name":"Journal of pharmacological and toxicological methods","volume":"135 ","pages":"Article 107838"},"PeriodicalIF":1.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145095357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Historical control data of nonclinical nerve conduction parameters in nonhuman primates","authors":"Andrew R. Brown,&nbsp;Nataliya Sadekova,&nbsp;Kevin Norton,&nbsp;Mark C. Freke","doi":"10.1016/j.vascn.2025.107837","DOIUrl":"10.1016/j.vascn.2025.107837","url":null,"abstract":"<div><div>Damage to the peripheral nervous system (neuropathy) can develop as a side effect of certain classes of therapeutic compounds or from toxin exposure, disease, and traumatic injury. Given the clinical significance of neuropathy, it can be critical to characterize nerve function during the nonclinical safety assessment of certain classes of compounds. Additionally, recent characterization of dorsal root ganglion toxicity following adeno-associated viral therapies stresses the need for in vivo assessment of potential nerve damage on these studies. Nerve conduction evaluations provide an electrophysiological approach to assess nerve function, are a sensitive and valid index of induced neuropathies, can be conducted at multiple time points throughout the treatment period, and provide quantitative data for evaluation. Here, we present a dataset of normative values for nerve conduction parameters in nonhuman primates generated by a retrospective analysis of historical control data from 16 Charles River studies comprising 491 young adult male and female cynomolgus monkeys, approximately 1.5–5 years of age. Nerve panels consisted of distal hindlimb peroneal motor and sural sensory nerves, a proximal mixed segment of the hindlimb sciatic nerve, and distal forelimb median sensory nerve. Evaluation parameters included response onset latency, nerve conduction velocity (NCV), and amplitude, as appropriate, for each nerve with animal sex and country of origin as independent variables. NCV values for each nerve were largely consistent between studies while response amplitudes exhibited more variability, indicating the importance of establishing prestudy baselines and incorporating a concurrent control group for postdose assessments. No sex differences were observed for NCV or amplitude parameters, indicating that sexes can be pooled to increase sample size and experimental power while potentially reducing the total animals required for each study. An animal country of origin effect on response parameters was observed which related, in part, to differences in animal size. Collectively, the dataset provides a comprehensive overview of control values for young adult cynomolgus monkeys to assess the sensitivity of the technique to properly characterize a potential effect. It is considered suitable to aid in the interpretation of potential neuropathy for nerve conduction evaluations used in nonclinical toxicology studies.</div></div>","PeriodicalId":16767,"journal":{"name":"Journal of pharmacological and toxicological methods","volume":"135 ","pages":"Article 107837"},"PeriodicalIF":1.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145095356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of in vitro IKr/hERG assays under physiological temperature conditions using the semi-automated patch-clamp system QPatch compact with temperature control system","authors":"Kazuya Tsurudome,&nbsp;Hironori Ohshiro,&nbsp;Taku Izumi","doi":"10.1016/j.vascn.2025.107814","DOIUrl":"10.1016/j.vascn.2025.107814","url":null,"abstract":"<div><div>Cardiac ion channel activity is crucial for generating cardiac action potentials with proper timing and duration. Drug-induced impairment of these ion channels can cause abnormal cardiac activity, including QT interval prolongation, ventricular arrhythmia, and, in the most severe cases, sudden death. These adverse effects are among the leading reasons for drug withdrawal from the market or the denial of regulatory approval for new therapeutic candidates. The ICH E14/S7B Q&amp;A released in August 2022 provided recommended conditions for best practices for in vitro assay of IKr/hERG to maintain reproducibility and consistency in evaluations. These recommendations include testing under physiological temperature conditions, as well as considering factors such as voltage protocols. In this study, we have investigated whole-cell patch-clamp measurements of hERG currents under physiological temperature conditions (36–37 °C) using the semi-automated patch-clamp system QPatch compact using the recommended best practices. Whole-cell patch-clamp recordings in hERG channel-expressing cells were performed using the QPatch Compact automated patch-clamp system with a temperature control system and the voltage protocol recommended by the CiPA project. Compared to room temperature conditions, the rise time of the hERG current was shorter and its amplitude larger under physiological temperature conditions. The tail current decay rate was also slower. The overall duration of the current was prolonged. These findings imply that temperature influences the dynamics of hERG channels, providing a more accurate reproduction of their physiological function. Furthermore, when testing the temperature-dependent effects of erythromycin, the current inhibition rate at the highest applied concentration of 1000 μM was around 50 % under room temperature conditions (25 °C). In contrast, under physiological temperature conditions, the IC50 was approximately 60 μM, and a nearly complete blockade of hERG currents was achieved at 1000 μM. This result confirms that the inhibitory effect of erythromycin is more pronounced under physiological temperature conditions. Additionally, we have tested other reference compounds, such as dofetilide, ondansetron, and moxifloxacin, to assess their temperature sensitivity. These insights are expected to improve our understanding of the influence of temperature on drug effects and enhance the reliability of testing protocols in accordance with ICH guidelines.</div></div>","PeriodicalId":16767,"journal":{"name":"Journal of pharmacological and toxicological methods","volume":"135 ","pages":"Article 107814"},"PeriodicalIF":1.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145094844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Results from an EFPIA, JPMA, PhRMA industry survey on reopening and revamping the ICH S7A guidance on safety and secondary pharmacology","authors":"Jean-Pierre Valentin ,&nbsp;Katsuyoshi Chiba ,&nbsp;Derek J Leishman ,&nbsp;Emma Pawluk ,&nbsp;Hugo M. Vargas ,&nbsp;Takashi Yoshinaga","doi":"10.1016/j.vascn.2025.107763","DOIUrl":"10.1016/j.vascn.2025.107763","url":null,"abstract":"<div><div>The ICH S7A guideline on safety pharmacology has remained unchanged since its inception in 2000, fulfilling its crucial role in safeguarding clinical trial participants and patients (ICH S7A). However, in the meanwhile there has been significant scientific and technological advancements in drug safety science, a paradigm shifts of the drug discovery and development process, and an continuously evolving regulatory landscape, that led to the recommendation to revisit, adapt and evolve the ICH S7A guideline (Valentin &amp; Leishman, 2023, 2025). A revision of the guidance would imply opening an ICH process, the first step consists in the development of a ‘concept paper’. In that context, a survey has been developed to determine which elements, if any, of the ICH S7A guideline should be revised. Sixty-five (65) responses were obtained from industry representatives of companies affiliated to EFPIA, JPMA or PhRMA. Overall, there was a large support to revisit most of the pillars originally identified via a ‘revision’ or a ‘Q&amp;As’ ICH procedure. These include revisiting the ‘core battery’ assessment (58 to 68 %), the adversity concept (77 %), the modality agnosticism of the guideline (89 %), the in vitro secondary pharmacology component (85 %), the integrated risk assessment principles (75 %), and the inclusion of safety pharmacology endpoints in general toxicology studies (72 %). However, there were fewer than 50 % positive responses to revisiting the timing of the studies with respect to drug development stages and the validation or qualification principles to be applied to novel assays and models (&lt;50 % of positive responses). Notably, the majority of respondents viewed the ‘core battery’ studies as valuable, whereas ‘supplemental’ studies were less frequently seen as contributing additional value. Moreover, many indicated that they routinely perform safety pharmacology studies outside of these predefined categories—such as exploratory, mechanistic, or investigative studies. Overall, there was a large agreement between the responses from all territories. The survey results captured which elements of the ICH S7A guideline should be revised to help the development of a formal ICH concept paper.</div></div>","PeriodicalId":16767,"journal":{"name":"Journal of pharmacological and toxicological methods","volume":"135 ","pages":"Article 107763"},"PeriodicalIF":1.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144277091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lipopolysaccharide-induced abdominal nociception behavioral model in adult zebrafish (Danio rerio)","authors":"Maria Rayane Correia de Oliveira ,&nbsp;Sacha Aubrey Alves Rodrigues Santos ,&nbsp;Gabriela Alves do Nascimento ,&nbsp;João Gabriel Leite da Silva ,&nbsp;Luiz Francisco Wemmenson Gonçalves Moura ,&nbsp;Paulo Adenes Teixeira Coelho ,&nbsp;Lorena Silva Lima ,&nbsp;Keciany Alves de Oliveira ,&nbsp;Francisco Lucas Alves Batista ,&nbsp;Daniela Braga de Sousa ,&nbsp;Francisco Bastos Cavalcante Sobrinho ,&nbsp;Sandra Maria Barbosa de Araújo ,&nbsp;Antonio Gustavo de Almeida Batista ,&nbsp;Djane Ventura de Azevedo ,&nbsp;Franciglauber Silva Bezerra ,&nbsp;Larissa Morais Ribeiro da Silva ,&nbsp;Maria Izabel Florindo Guedes ,&nbsp;Henrique Douglas Melo Coutinho ,&nbsp;Renalison Farias-Pereira ,&nbsp;Ramon da Silva Raposo ,&nbsp;Francisco Ernani Alves Magalhães","doi":"10.1016/j.vascn.2025.107748","DOIUrl":"10.1016/j.vascn.2025.107748","url":null,"abstract":"<div><div>In this study a behavioral model of LPS-induced abdominal nociception was developed on adult zebrafish (<em>Danio rerio</em>), aZF. Initially, the toxicity of different LPS concentrations was assessed. The abdominal nociceptive response to the lowest LPS concentration was then analyzed, and the impact of sex on this nociceptive response was evaluated. The behavioral model of abdominal nociception was defined using the antinociceptive effects of morphine and diclofenac sodium. The mechanism of the possible involvement of TRPA1 in LPS-induced abdominal nociception was evaluated using HC-030031. Additionally, was investigated whether naloxone could modulate morphine's antinociceptive effect. The Light &amp; Dark Test was conducted to assess any potential anxiolytic-like effect of LPS. The Open Field Test was performed to evaluate the possible sedative effect/or not of morphine and diclofenac sodium. As a result, the tested LPS endotoxin solutions were not endotoxic against aZF (LC₅₀&gt;0.25 mg/mL). LPS significantly increased the abdominal nociceptive behavior of aZF. Sex did not affect the response profile to the endotoxin. Morphine and diclofenac sodium inhibited abdominal nociception induced by LPS and the effect of morphine was blocked by naloxone. HC-030031 significantly inhibited abdominal nociception induced by LPS. The LPS did not cause an anxiolytic-like effect. Morphine and diclofenac sodium did not affect the locomotion of the animals. The results suggest that aZF can be used as a behavioral model of abdominal nociception induced by LPS endotoxin.</div></div>","PeriodicalId":16767,"journal":{"name":"Journal of pharmacological and toxicological methods","volume":"135 ","pages":"Article 107748"},"PeriodicalIF":1.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144035113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analyzing atrial human iPSC-cardiomyocyte responses to GPCR and ion channel modulators: Introducing a chamber-specific cell model for preclinical testing","authors":"Bettina Lickiss ,&nbsp;Peter Linder ,&nbsp;Jan Hunker ,&nbsp;Steven D. Broadbent ,&nbsp;Jamie R. Bhagwan ,&nbsp;Jan Turner ,&nbsp;Elena Dragicevic ,&nbsp;Sonja Stoelzle-Feix ,&nbsp;Matthias Gossmann","doi":"10.1016/j.vascn.2025.107832","DOIUrl":"10.1016/j.vascn.2025.107832","url":null,"abstract":"<div><div>Over the past decade, commercial human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have emerged as vital tools for preclinical cardiac risk assessment, thanks to their human origin and limitless reproducibility. Commonly, mixed cell populations comprising ventricular, atrial, and nodal cardiomyocytes are used. However, diseases such as atrial fibrillation, impacting over 33 million individuals globally, underscore the urgent need for cardiac subtype-specific commercial cell lines. Here, we characterize commercially available hiPSC-derived atrial cardiomyocytes (atrial hiPSC-CMs) and compare them to hiPSC-derived ventricular cardiomyocytes (ventricular hiPSC-CMS) (both Axol Biosciences) regarding their contractile properties using FLEXcyte 96 technology. The cells were seeded on flexible 96-well plates mimicking physiological human heart conditions <em>in vitro</em>. Pre-compound beat characteristics were analyzed regarding beat rate and amplitude. Compound-induced effects of GPCR agonists acetylcholine and carbachol were tested regarding contractile properties including beat rate, amplitude and beat duration using a concentration range of 1 μM – 100 μM. Furthermore, ion channel modulators including S-Bay K8644, ivabradine, vernakalant and 4-Aminopyridine were assessed at 4 different concentrations ranging from 100 nM – 1 μM. Pre-compound analysis reveals cell type-specific beat shapes analogous to the respective cardiac action potential, in which atrial cells show a higher beat rate and less pronounced contraction force compared to ventricular cells. Pharmacological analysis demonstrates a higher susceptibility of atrial hiPSC-CMs towards GPCR agonists acetylcholine and carbachol than ventricular cells. Ion channel modulator S-Bay K8644 induces reversed inotropic and chronotropic effects in atrial and ventricular cells, while ivabradine causes a pronounced negative chronotropic effect in atrial cells alone. 4-Aminopyridine reveals prolonged contraction duration and reduced chronotropy in atrial hiPSC-CMs, while vernakalant induces opposing reactions in chronotropy of chamber-specific cardiomyocytes. These results underscore the significant pharmacological responses of atrial hiPSC-CMs and their utility on a multiwell contractility platform for enhancing <em>in vitro</em> cardiac liability studies and disease modeling.</div></div>","PeriodicalId":16767,"journal":{"name":"Journal of pharmacological and toxicological methods","volume":"135 ","pages":"Article 107832"},"PeriodicalIF":1.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145095005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ventricular electromechanics in a cardiac glycoside arrhythmia model in isoflurane-anaesthetised New Zealand White (NZW) rabbits","authors":"Gail E. Geist,&nbsp;Deborah Calantropio-Covington,&nbsp;Lindsay Bates,&nbsp;Angelica Cabrera","doi":"10.1016/j.vascn.2025.107830","DOIUrl":"10.1016/j.vascn.2025.107830","url":null,"abstract":"<div><div>Cardiac glycoside (CG) intoxication models are well-established tools to evaluate non-torsadogenic arrhythmic liabilities in vivo. However, preparations using practical inhalant anesthetics, particularly in rabbits, a highly translational species for preclinical electrophysiology and functional assessments, are seldom described. In this study, we characterize CG-induced cardiovascular responses under isoflurane anesthesia in an optimized in vivo rabbit preparation. Ventilated male NZW rabbits (<em>n</em> = 4–6/group, 6-month old) were administered either digoxin (DIG, 40 μg/kg/min IV) or ouabain (OUA, 15 μg/kg/min IV) after anesthetic stabilization under isoflurane inhalant (1.5–2 %) and butorphanol (0.2 mg/kg/h IV). Animals were vagotomized and instrumented for lead-II ECG, catheter-based arterial (MAP) and left-ventricular pressures (LVP), and pericardiectomized to permit electrophysiological mapping. Electromechanical window (EMW) was derived from ECG and LVP signals. The effects of concurrent beta-adrenergic stimulation with dobutamine (+DOB: 2.5 μg/kg/min) were evaluated in a subset of OAU rabbits. At baseline (BL), heart rate (HR: 266 ± 44 bpm), hemodynamics (MAP: 60 ± 10 mmHg), ECG intervals (QT: 146 ± 21 msec), and electromechanical indices (dPdtmax: 2551 ± 1144 mmHg/s, EMW: 46 ± 11 ms) were reflective of normal physiology in rabbits. Under CG administration, sustained ventricular ectopy (SVE, &gt;30 s) and ventricular fibrillation (VF) were reliably and successively induced (DIG SVE: 22.2 ± 3 min, VF: 34.7 ± 5 min; OUA SVE: 8.5 ± 2 min, VF: 16 ± 2 min). Prior to SVE and consistent with CG toxicity, animals demonstrated robust increases in indices of inotropy (dPdtmax: DIG: +92 ± 47 %, OUA: +116 ± 43 %), afterload (MAP: DIG: +58 ± 34 %; OUA:+50 ± 14 %), and serum potassium ([K+]: DIG: +40 ± 11 %; OUA: +47 ± 15 %). Heart rate was equivalent to baseline in both preparations, aligning to pre-existing vagal withdrawal (DIG: +2 ± 11 %, OUA: -0.4 ± 3 %). EMW was variable but remained positive in all animals before SVE (EMW DIG: 44 ± 21 msec; OUA: 40 ± 11 msec) with nominal QT change (DIG: -2 ± 11 %, OUA: +5 ± 6 % vs. BL). Beta-adrenergic stimulation accelerated the time to OUA-induced SVE and VF (+DOB: −19 % and − 10 %, respectively vs. OUA). Taken together, these data strongly suggest that rabbits instrumented under a contemporary isoflurane anesthetic regimen constitute a viable model of cardiac glycoside induced ventricular arrhythmias, characterized by predictable and progressive ectopy that is sensitive to pharmacological modulation.</div></div>","PeriodicalId":16767,"journal":{"name":"Journal of pharmacological and toxicological methods","volume":"135 ","pages":"Article 107830"},"PeriodicalIF":1.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145095003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discriminating evidence – Use and misuse of the drug discrimination test in abuse potential assessments of novel CNS drugs","authors":"David J. Heal ,&nbsp;Jane Gosden ,&nbsp;Sharon L. Smith","doi":"10.1016/j.vascn.2025.107792","DOIUrl":"10.1016/j.vascn.2025.107792","url":null,"abstract":"<div><div>Drug-discrimination is a mandatory test for evaluating abuse potential of CNS drug‑candidates. The major challenge is designing translationally valid protocols for drug-candidates with novel pharmacological mechanisms and no affinity for targets mediating the psychoactive effects of known substances of abuse. We assessed predictive validity of 3 experimental protocols using our and other published data. Experimental protocols: (1) Drug‑candidate tested in animals trained to discriminate a selected abused substance from vehicle, (2) Drug-candidate investigated in multiple studies with animals trained to recognize representatives from major abused drug classes; (3) Drug-candidate used as training cue with back-testing of various abused substances. Female rats were trained to discriminate d-amphetamine (0.25–0.5 mg/kg,ip) from saline. Full, Partial, and No Generalization: ≥75 %, ≥60 % and &lt; 25 % drug‑associated lever-presses. Microdialysis measurements of extracellular dopamine in accumbens (ACB) or striatum (STR) were made in freely‑moving rats. Generalization to d-amphetamine (mg/kg[route]): lisdexamfetamine (3.4[po]); phentermine (3.0[po]); methylphenidate (5.0[po]); bupropion (30[po]); methamphetamine (0.5[ip]); fencamfamine (3.0[ip]); cocaine (10[ip]). Partial generalization &lt;60 %: sibutramine (3.0[ip]); modafinil (100[ip]). No generalization: atomoxetine (10[po]); desipramine (5.0[ip]); venlafaxine (10[ip]). Only drugs markedly increasing dopamine neurotransmission in ACC/STR generalized to d‑amphetamine. Drugs producing small/moderate dopamine increases in ACB/STR and/or increased dopamine in prefrontal cortex did not produce full or ≥ 60 % generalization to d-amphetamine. Dopamine D₂ antagonists blocked d‑amphetamine's discriminative cue and its reinforcing effect in humans [1,2] showing the pharmacological specificity of both effects. Drug-discrimination findings with other substances of abuse, e.g. cannabinoids, psychedelics, GABA-A positive allosteric modulators (PAMs), glutamatergic ligands, confirm the hypothesis. Results obtained using the drug‑candidate as training cue showed this experimental approach is not viable [3,4]. Evaluation of approaches 1–3: (1) Has weaknesses, but highest predictive validity. (2) Invalid, except when drug-candidate has pharmacology shared with selected abused substances. Behavioral similarity does not produce generalization or have predictive validity. (3) Invalid. No evidence that generalization to drug-candidate would generate any meaningful information or predict abuse potential.</div><div>[1] Lile et al., 2005; [2] Rush et al., 2003; [3] Swedberg et al., 2014; [4] Swedberg &amp; Raboisson, 2014.</div></div>","PeriodicalId":16767,"journal":{"name":"Journal of pharmacological and toxicological methods","volume":"135 ","pages":"Article 107792"},"PeriodicalIF":1.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145095192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}