Journal of pharmacological and toxicological methods最新文献

{"title":"Concordance of cardiovascular contractility between FLEXcyte assay and the rat left ventricular catheterized telemetry model","authors":"Jason D. Payseur,&nbsp;Xuejun Wu,&nbsp;Elizabeth Holliday,&nbsp;Shuya Wang,&nbsp;Earl Gordon,&nbsp;Eric I. Rossman,&nbsp;Ajeesh K. Cherian","doi":"10.1016/j.vascn.2025.107827","DOIUrl":"10.1016/j.vascn.2025.107827","url":null,"abstract":"<div><div>Changes in cardiac contractility can lead to hemodynamic alterations and abnormal structural changes within the heart, which over time can cause reduced function and failure. Recent advancements in technology, allowing the assessment of cardiac contractility to become easier and more efficient, have resulted in a greater focus on contractility measures within safety pharmacology studies. In particular, the development of in vitro assays such as the FLEXcyte assay, which utilizes human stem cell derived cardiomyocytes (hiPSC-CMs), allows for the ability to screen for potential contractility changes earlier in development. The objective of this study was to explore the concordance of changes in contractility between FLEXcyte measurements and left ventricular pressure measurements (LV + dP/dt_max) in the telemetered rat model. Verapamil and milrinone were selected as tool compounds. For the FLEXcyte, hiPSC-CMs (Cardiosight-S; NEXCEL Co., Ltd.) were maintained in a serum-free culture medium for 7 days with media changes every 48 h. Initially, 30 s of baseline was recorded every 15 min for 1 h. Following baseline, a dose response curve was attained using 5 concentrations. Spontaneous beat rate and contraction amplitude were analyzed to determine the concordance with heart rate and LV + dP/dt_max in the telemetered rat. For the telemetered study, CRL WI(Han) rats were instrumented with HD-S21 (DSI) implants monitoring systemic and LV pressures and placed into a 4 × 4 latin square design for each tool compound. For verapamil, the FLEXcyte showed an increase in beat rate (22.7 % at 33 nM) and a substantial decrease in amplitude (66.5 % at 33 nM), which concords well with the increase in heart rate (25.2 %) and decrease in LV + dP/dt_max (−33.6 %) in the telemetered rat. However, for milrinone, the FLEXcyte did not show any significant changes in beat rate or amplitude while the telemetered rat showed increases in both heart rate (up to 57 %) and LV + dP/dt_max (up to 87.4 %). While more work is needed, this data highlights the importance of conducting both in vitro and in vivo studies to assess the potential effects on cardiac contractility in drug development, allowing for the identification of molecules with diverse mechanisms of action.</div></div>","PeriodicalId":16767,"journal":{"name":"Journal of pharmacological and toxicological methods","volume":"135 ","pages":"Article 107827"},"PeriodicalIF":1.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145094994","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":"Assessing the cardiotoxicity of 31 compounds using a multiplexed kinetic image cytometry (KIC)-based assay: Harnessing the predictive power of human iPSC-cardiomyocytes for early drug development","authors":"Ranor C.B. Basa ,&nbsp;Randall S. Ingermanson ,&nbsp;Filiberto Catalan-Perez ,&nbsp;Ricardo Serrano ,&nbsp;Ariel Wang ,&nbsp;Alyson Smith ,&nbsp;Jeffrey M. Hilton ,&nbsp;Patrick M. McDonough ,&nbsp;Cherie Handley ,&nbsp;Lilian Harrison ,&nbsp;Ameena Pascua ,&nbsp;Mark Mercola ,&nbsp;Jeffrey H. Price","doi":"10.1016/j.vascn.2025.107820","DOIUrl":"10.1016/j.vascn.2025.107820","url":null,"abstract":"<div><div>Human-induced pluripotent stem cell (hiPSC) models are more species-relevant than animal models and are amenable to high-throughput scalability. Previously, our Kinetic Image Cytometry (KIC) proarrhythmia assay examining calcium kinetics in hiPSC-cardiomyocytes (CMs) had a clinical accuracy of ~90 % (Pfeiffer, <em>et al.</em>, 2016); when augmented with deep learning, accuracy increased to 95 % (Serrano, <em>et al.</em>, 2023). Expanding upon this work, we screened 31 compounds with known clinical effects (effector classes: sarcoplasmic reticulum/calcium release, plasma membrane/ion channel, mitochondrial/myosin, and negative controls) in a 7-point concentration-response format—bracketing clinical exposures—using a panel of patient-derived hiPSC-CMs. We loaded hiPSC-CMs with Cal-520 (a green-channel calcium indicator), BeRST-1 (a far red-channel membrane voltage dye), TMRM (a mitochondrial membrane potential dye), and Hoechst (for nuclei), then exposed them to test compounds acutely. We then acquired interleaved calcium and voltage movies at 60 Hz (30 Hz/channel) as well as single images of TMRM and Hoechst. Vala's image analysis software, CyteSeer, was used to simultaneously measure calcium/action potential (AP) kinetics on—and to derive contraction metrics from—those movies. Furthermore, we mathematically characterized and classified calcium/AP waveforms to quantify compound-induced cardiotoxic effects. Additionally, we assessed mitochondrial health (using TMRM fluorescence) as well as acute cytotoxicity (using nucleus morphology) in the same experiment. By multiplexing these readouts on a single-cell level, we were able to correctly classify 30/31 (96.8 %) compounds on the basis of earliest-observed adverse effects (if any) by primary effector class at clinically-relevant test concentrations. While the data were more complex than initially expected (<em>e.g.</em>, due to pleiotropic clinical effects and/or multiple efficacy−/toxicity-related targets), this multiplexed approach has the potential to elucidate mechanistic classes or targets quickly; and some of the more unexpected results from our screen highlight the need for de-risking early in drug development using relatively inexpensive and highly scalable hiPSC models. A larger study is currently underway to examine a library of 300+ compounds in order to comprehensively validate and refine our multiplexed assay.</div></div>","PeriodicalId":16767,"journal":{"name":"Journal of pharmacological and toxicological methods","volume":"135 ","pages":"Article 107820"},"PeriodicalIF":1.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145094615","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":"SmartHeart: An innovative high throughput assay to generate and assess cardiac micro tissues from hiPSCs answering to the current challenges of drug discovery","authors":"Ahmed Khedher ,&nbsp;Patricia Davidson ,&nbsp;Pauline Thiebaud ,&nbsp;Stijn Robben ,&nbsp;Cyril Cerveau ,&nbsp;Jamie Bhagwan ,&nbsp;Mael Le Berre ,&nbsp;Rita S.R. RIbeiro","doi":"10.1016/j.vascn.2025.107821","DOIUrl":"10.1016/j.vascn.2025.107821","url":null,"abstract":"<div><div>Cardiac adverse events are among the top reasons for discontinuing drugs in early clinical phase studies, where drugs with cardiotoxic liabilities are responsible for one third of regulatory failures. These alarming statistics highlight the widespread occurrence and significant financial burden of ineffective drugs that proceed from preclinical animal studies. Despite advancements in cardiac bioengineering, challenges remain regarding physiological relevance, cost, and throughput. To address these challenges, an innovative 3D cardiac model, the SmartHeart (SH), was developed. This model facilitates the self-assembly and maturation of ring-shaped cardiac tissues and allows for precise in-situ measurements of various parameters (e.g. contraction stress, strain, beating metrics, membrane action potential and calcium signaling). The technology is based on standard 96-well plates coated with a structured hydrogel, which features an array of conical-shaped microwells, each surrounding a central pillar. Within less than 48 h after cell seeding, the tissues (composed of iPSC-derived ventricular cardiomyocytes (Axol) and fibroblasts) demonstrated rhythmic contractions. The contractility stress and strain as well as the beating rate of the tissues were quantified by monitoring the variation of the central pillar's area with known stiffness (12 kPa) with time. After 14 days, the tissues presented morphological signs of maturation and were exposed to several classical drugs. The presence of isoproterenol caused a positive inotropic and chronotropic response. A negative inotropic response was induced by nifedipine and the tissues became quiescent when exposed to high doses of mexiletine, which is consistent with its known pharmacological effects as a sodium channel blocker. The hydrogel's optical transparency allows compatibility with high-resolution image-based techniques. This includes the use of voltage-sensitive fluorescent dyes, such as FluoVolt that showed an intensity spike just before the tissue contraction. Likewise, cellular spatial organization and intracellular morphology, e.g. cardiomyocyte cytoskeletal fiber elongation and striation, showing signs of maturation, could be visualized using immunofluorescence. In conclusion, the SmartHeart 3D-cardiac model provides an advanced solution to the ongoing challenges in drug discovery by enabling precise, real-time monitoring of cardiac tissue function and maturation. This innovative platform offers robust and relevant readouts for high-throughput and high-content screening, significantly enhancing the assessment of drug efficacy and safety.</div></div>","PeriodicalId":16767,"journal":{"name":"Journal of pharmacological and toxicological methods","volume":"135 ","pages":"Article 107821"},"PeriodicalIF":1.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145094719","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":"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":"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}

{"title":"Are current rat studies sensitive to detect blood pressure changes per the new FDA draft clinical blood pressure guidance?","authors":"Kamila J. Sadko ,&nbsp;Derek J. Leishman ,&nbsp;Hannah Garver ,&nbsp;Gregory Fink ,&nbsp;Marc B. Bailie ,&nbsp;Adam Lauver","doi":"10.1016/j.vascn.2025.107777","DOIUrl":"10.1016/j.vascn.2025.107777","url":null,"abstract":"<div><div>Released in 2022, the FDA's draft guidance “Assessment of Pressor Effects of Drugs”, proposes that a dedicated clinical study for chronic use drugs should be powered to rule out a potential systolic arterial blood pressure (BP) increase of 3 mmHg over 24 h. Given the resource commitment of clinical studies, sensitive nonclinical prediction of potentially meaningful BP increases would be valuable. This study aimed to determine the utility of long-term rat studies for detecting acute and chronic blood pressure changes. We hypothesized that studies using rats have adequate stability and variability to detect BP changes ≥3 mmHg over several weeks. Available data from a historic rodent assessment of 80 days duration (<em>N</em> = 9) in vehicle treated Sprague Dawley rats was used. The data were assessed for minimal detectable differences (MDDs), least significant differences (LSDs), and changes from baseline for all BP measures in light and dark 12 h, days, and weeks. Day 15 was used as the reference day and Day 43 as the comparison for day-to-day and light and dark changes from baseline to simulate a 4-week study with a week-long baseline assessment. In week comparison, week 2 was compared to week 5. A one-way <em>t</em>-test was conducted against an assumed mean difference of 0 to evaluate for significance. Study average difference from baseline for the dark cycle were 1.80 ± 1.42 (mean ± standard deviation), 1.99 ± 1.34, and 1.86 ± 1.25 mmHg for diastolic (Dia), systolic (Sys), and mean arterial pressure (MAP), respectively. Light cycle differences were 0.54 ± 1.23, −0.04 ± 1.101, and 0.143 ± 0.91 mmHg for Dia, Sys, and MAP . Day-to-day differences of 1.21 ± 1.29, 0.89 ± 1.12, and 0.931 ± 1.01 mmHg for Dia, Sys, and MAP were seen. Week-to-week differences were − 2.55 ± 1.47 mmHg for Sys, 2.30 ± 1.29 mmHg for MAP, and 1.87 ± 1.22 mmHg for Dia. Results were not significantly different from 0. Overall, rats demonstrated small insignificant changes from baseline in their blood pressure measures across a longitudinal study. The low variability observed was sufficient to encourage further evaluation of the minimal detectable differences which is currently underway.</div></div>","PeriodicalId":16767,"journal":{"name":"Journal of pharmacological and toxicological methods","volume":"135 ","pages":"Article 107777"},"PeriodicalIF":1.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145095344","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":"Validation of in vivo QT ICH E14/S7B Q&A guidance in minipig","authors":"Rachael Hardman ,&nbsp;Joyce Obeng ,&nbsp;Jill Nichols ,&nbsp;Karim Melliti","doi":"10.1016/j.vascn.2025.107778","DOIUrl":"10.1016/j.vascn.2025.107778","url":null,"abstract":"<div><div>The E14/S7B Q&amp;A guidelines introduce the concept of “double negative” (negative hERG and negative in vivo QTc) non-clinical data which can be used along with negative Phase 1 clinical QTc data to substitute for a clinical Thorough QT study in specific cases (Q&amp;As 5.1 and 6.1). The non-clinical data are to be generated using “best practice” designs in order to support data quality and consistency across the industry. For the in vivo QT assay, best practice recommendations require characterization of individual study sensitivity, verification of independence QTc from heart rate, demonstration of test facility sensitivity and pharmacological translation to human using a positive control. We have previously validated E14/S7B Q&amp;A compliant in vivo QT assays in dog and non-human primate. The objective of this work was to perform the validation in the minipig as the third non-rodent species commonly used for cardiovascular safety assessment. A positive control telemetry study was performed with moxifloxacin (30, 120, 300 mg/kg) using a double Latin square crossover study design (<em>n</em> = 8), followed by an ascending dose design (<em>n</em> = 5). A single PK sample was drawn during the telemetry phase, and a separate full PK phase was included at all dose levels for PK/PD assessment to determine translation to human. Moxifloxacin-induced increases in QTc were observed, with a maximal increase at the highest dose of 86 and 67 msec for the double cross-over and ascending dose designs, respectively. Smallest statistically detectable differences (SSDD) for QTc were 11 msec for the double cross-over and 10 msec for the ascending dose design. Based on the free plasma exposures and magnitude of the QTc effects from the crossover data, a 10 msec effect was observed at 0.77× of the free moxifloxacin concentration known to produce a 10 msec QTc effect in human. In conclusion, we have validated an E14/S7B Q&amp;A compliant in vivo QT assay in the minipig for both cross-over and ascending dose designs and shown good translation to human, completing the Labcorp™ offering for in-vivo E14/S7B Q&amp;A compliant studies.</div></div>","PeriodicalId":16767,"journal":{"name":"Journal of pharmacological and toxicological methods","volume":"135 ","pages":"Article 107778"},"PeriodicalIF":1.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145095349","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":"Evaluation of laser optoporation-induced action-potential-like measurements on iPSC-cardiomyocytes and the assessment of drug-induced effects on APD and contractility","authors":"Jin Chang","doi":"10.1016/j.vascn.2025.107812","DOIUrl":"10.1016/j.vascn.2025.107812","url":null,"abstract":"<div><div>Physiological relevance and accuracy in cardiac safety pharmacology studies is of the utmost importance, as supported by the recent changes in ICH guidelines and the CiPA committee's efforts. Although most of the studies focused on hERG-affecting molecules and the arrhythmic risk related to Action Potential elongation, iPSC-derived cardiomyocytes have the potential to be a more thorough assay with more physiological relevance. In this study, we demonstrate how laser optoporation technology opens transient nanopores within the cell's membrane and allows for Action Potential (AP) recordings from cardiac cells and compare the results to traditional MEA-based Field Potential Measurements. In particular, we show how the response to a potassium channel blocker (dofetilide) is comparable when looking at the APD90(&gt;30 % increase) but that the APD30 is shortened (&gt;10 % decrease) which we would not be able to measure with traditional MEA. The response to an Ica blocker (Nifedipine) reveals how the drug affects the depolarization currents, which can not be measured with traditional MEA. In addition, Beta-adrenergic (isoproterenol) receptor response demonstrated how the AP-amplitude remains unchanged while the contractility is increased (&gt;30 %). We also show how the technology is non-invasive and label-free, allowing for reliable and stable measurements over 3 weeks, and how the results are comparable to previous validated data. With these results, we suggest further exploration of this technique in its use in safety pharmacology to predict cardiotoxic effects, potentially serving as an upgrade on previous technology which was limited to Field Potential Duration elongation effects.</div></div>","PeriodicalId":16767,"journal":{"name":"Journal of pharmacological and toxicological methods","volume":"135 ","pages":"Article 107812"},"PeriodicalIF":1.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145094842","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}