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Ritchie HE, Polson JW, Xia A, Webster W. Effect of vinpocetine on embryonic heart rate in vitro. Curr Res Toxicol 2023; 5:100125. [PMID: 37753450 PMCID: PMC10518341 DOI: 10.1016/j.crtox.2023.100125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/11/2023] [Accepted: 09/14/2023] [Indexed: 09/28/2023] Open
Abstract
Vinpocetine is a readily available nutritional supplement claimed to improve memory and weight loss. However, it blocks the Ikr current essential for cardiac action potential repolarisation and Ikr inhibition can cause "torsade de pointes" arrhythmias and sudden death. Moreover, Ikr blockers have exhibited teratogenic effects in reproductive toxicology studies, leading to increased birth defects and embryonic mortality. The FDA advises against vinpocetine use in pregnant and prospective mothers based on animal studies showing dose-dependent fetal mortality in rats and rabbits, and cardiovascular malformations in surviving fetuses. However, the mechanisms responsible for vinpocetine's fetal toxicity remain unclear. The present study used rat embryo culture to evaluate vinpocetine and its major metabolite, apovincaminic acid, on embryonic heart rate, a possible causative factor behind its adverse effects. Both compounds induced embryonic bradycardia in a concentration-dependent manner, with vinpocetine proving more potent. The minimum vinpocentine concentration to induce bradycardia was 100 nM, a level unlikely to be reached in humans following typical doses. Embryonic arrhythmias were also observed at the highest concentrations. These results suggest that the FDA's cautionary statement may generate undue anxiety, although re-evaluation of teratogenicity risk associated with vinpocetine should be revisited if a link to cardiac arrhythmias in adults is established.
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Affiliation(s)
- Helen Elizabeth Ritchie
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, NSW, Australia
| | - Jaimie W. Polson
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, NSW, Australia
| | - Andrea Xia
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, NSW, Australia
| | - William Webster
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, NSW, Australia
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Gao J, Zhang H, Xiong P, Yan X, Liao C, Jiang G. Application of electrophysiological technique in toxicological study: From manual to automated patch-clamp recording. Trends Analyt Chem 2020. [DOI: 10.1016/j.trac.2020.116082] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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The effect of anti-emetic drugs on rat embryonic heart activity. Reprod Toxicol 2019; 87:140-145. [PMID: 31199962 DOI: 10.1016/j.reprotox.2019.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 06/05/2019] [Accepted: 06/10/2019] [Indexed: 02/07/2023]
Abstract
Nausea and vomiting of pregnancy (NVP) is the most common medical complaint during pregnancy affecting up to 70% of pregnant women worldwide. Some antiemetic medications (AEM) (droperidol, domperidone, granisetron, metoclopramide and trifluoperazine) used to treat NVP have the unwanted side effect of hERG blockade. The hERG potassium channel is essential for normal heart rhythm in both the adult human and the human and rat embryo. Animal studies show hERG blockade in the embryo causes bradycardia and arrhythmia leading to cardiovascular malformations and other birth defects. Whole rat embryo in vitro culture was used to determine the effect of the above listed AEM and meclizine on the heart rate of Gestational day 13 rat embryos. These embryos are similar in size and heart development to 5-6-week human embryo. The results showed that all of the AEMs caused a concentration-dependent bradycardia. Droperidol had the lowest margin of safety.
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Quinidine Rebooted. JACC Clin Electrophysiol 2019; 5:383-386. [DOI: 10.1016/j.jacep.2019.01.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 01/10/2019] [Accepted: 01/17/2019] [Indexed: 11/17/2022]
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Ritchie HE, Telenius C, Gustaffson E, Webster WS. The effects of nifedipine and ivabradine on the functionality of the early rat embryonic heart. Are these drugs a risk in early human pregnancy? Birth Defects Res 2019; 111:281-288. [PMID: 30653849 DOI: 10.1002/bdr2.1457] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 12/10/2018] [Accepted: 12/28/2018] [Indexed: 01/13/2023]
Abstract
BACKGROUND When the human heart begins its earliest contractions from day 21, it lacks a functional autonomic nerve supply. Instead, contractions are generated by regular calcium transients later augmented by the funny current (If ) produced by sinoatrial-like cells. This study examined effects of blocking these currents in the early rat embryonic heart. METHODS Rat embryos were incubated in vitro with either the calcium channel blocker nifedipine and/or the funny current (If ) blocker ivabradine for 1 hr to examine the effects of these drugs on the activity of the embryonic heart. RESULTS On gestational day (GD) 10, nifedipine (0.45-1.8 μM) caused asystole at high concentrations (8/10 embryos at 1.8 μM and 3/10 embryos at 0.9 μM) and markedly increased embryonic heart rate (EHR) in all surviving embryos but likely reduced blood flow due to weak contractions. Ivabradine (1.5 μM) caused a 29% reduction in EHR in GD 10 embryos and a greater than 50% reduction in EHR for GD 11-14 embryos. Combined exposure to both nifedipine and ivabradine resulted in an additive effect. The increased EHR due to nifedipine was reduced by the ivabradine. CONCLUSION The results suggest that exposure to nifedipine in human pregnancy 3-4 weeks postfertilization may cause a direct effect on the embryonic heart resulting in reduced blood flow leading to abnormal heart and/or blood vessel development and/or embryonic death. Accidental exposure to ivabradine in the organogenic period would be expected to cause embryonic bradycardia, hypoxia, malformations, and embryonic death. This drug is currently contraindicated in pregnancy.
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Affiliation(s)
- Helen E Ritchie
- Discipline of Biomedical Sciences, Sydney School of Medical Science, The University of Sydney, Sydney, New South Wales, Australia
| | - Carolina Telenius
- Discipline of Anatomy and Histology, Sydney School of Medical Science, The University of Sydney, Sydney, New South Wales, Australia
| | - Elin Gustaffson
- Discipline of Anatomy and Histology, Sydney School of Medical Science, The University of Sydney, Sydney, New South Wales, Australia
| | - William S Webster
- Discipline of Anatomy and Histology, Sydney School of Medical Science, The University of Sydney, Sydney, New South Wales, Australia
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Danielsson B, Webster WS, Ritchie HE. Ondansetron and teratogenicity in rats: Evidence for a mechanism mediated via embryonic hERG blockade. Reprod Toxicol 2018; 81:237-245. [PMID: 30149139 DOI: 10.1016/j.reprotox.2018.08.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 08/23/2018] [Accepted: 08/23/2018] [Indexed: 01/02/2023]
Abstract
The potent hERG channel blocking drug ondansetron is used off-label for treatment of nausea and vomiting in early pregnancy. Some human epidemiological studies have associated ondansetron with fetal cardiovascular defects and orofacial clefts. This study investigated the effects of ondanestron on embryonic heart rhythm of gestational day (GD) 13 rat embryos in vitro and then integrated the results with published animal teratology, and animal and human pharmacokinetic studies to perform a risk evaluation. Ondansetron caused concentration dependent bradycardia and arrhythmia. Cardiovascular malformations in rats occurred at exposures slightly higher than those in early human pregnancy. Together the results suggest that ondansetron can have teratogenic potential in rats and humans mediated via hERG block and severe heart rhythm disturbances in the embryo. The risk may be increased in human pregnancy if additional risk factors are present such as hypokalemia.
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Affiliation(s)
- B Danielsson
- Swedish National Board of Health and Welfare, Stockholm, Sweden.
| | - William S Webster
- Discipline of Anatomy and Histology, Sydney Medical School, The University of Sydney, Sydney, NSW 2006, Australia.
| | - Helen E Ritchie
- Discipline of Biomedical Sciences, Sydney Medical School, The Unvieristy of Sydney, Sydney, NSW 2006, Australia.
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Ritchie HE, Oakes DJ, Kennedy D, Polson JW. Early Gestational Hypoxia and Adverse Developmental Outcomes. Birth Defects Res 2018; 109:1358-1376. [PMID: 29105381 DOI: 10.1002/bdr2.1136] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 09/01/2017] [Indexed: 12/14/2022]
Abstract
Hypoxia is a normal and essential part of embryonic development. However, this state may leave the embryo vulnerable to damage when oxygen supply is disturbed. Embryofetal response to hypoxia is dependent on duration and depth of hypoxia, as well as developmental stage. Early postimplantation rat embryos were resilient to hypoxia, with many surviving up to 1.5 hr of uterine clamping, while most mid-gestation embryos were dead after 1 hour of clamping. Survivors were small and many had a range of defects, principally terminal transverse limb reduction defects. Similar patterns of malformations occurred when embryonic hypoxia was induced by maternal hypoxia, interruption of uteroplacental flow, or perfusion and embryonic bradycardia. There is good evidence that high altitude pregnancies are associated with smaller babies and increased risk of some malformations, but these results are complicated by increased risk of pre-eclampsia. Early onset pre-eclampsia itself is associated with small for dates and increased risk of atrio-ventricular septal defects. Limb defects have clearly been associated with chorionic villus sampling, cocaine, and misoprostol use. Similar defects are also observed with increased frequency among fetuses who are homozygous for thalassemia. Drugs that block the potassium current, whether as the prime site of action or as a side effect, are highly teratogenic in experimental animals. They induce embryonic bradycardia, hypoxia, hemorrhage, and blisters, leading to transverse limb defects as well as craniofacial and cardiovascular defects. While evidence linking these drugs to birth defects in humans is not compelling, the reason may methodological rather than biological. Birth Defects Research 109:1358-1376, 2017.© 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Helen E Ritchie
- Discipline of Biomedical Science, Sydney Medical School, University of Sydney, Sydney, NSW
| | - Diana J Oakes
- Discipline of Biomedical Science, Sydney Medical School, University of Sydney, Sydney, NSW
| | | | - Jaimie W Polson
- Discipline of Biomedical Science, Sydney Medical School, University of Sydney, Sydney, NSW
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Prestipino L, Polson JW, Brolin E, Ritchie HE. Long-term programming effects on blood pressure following gestational exposure to the I Kr blocker Dofetilide. Physiol Rep 2018; 6:e13621. [PMID: 29504284 PMCID: PMC5835481 DOI: 10.14814/phy2.13621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 01/02/2018] [Accepted: 01/03/2018] [Indexed: 11/24/2022] Open
Abstract
A slow embryonic heart rate in early-mid gestation is associated with increased risk of embryonic death and malformation, however, the long-term consequences remain unknown. We administered Dofetilide (Dof, 2.5 mg/kg), a drug that produces embryo-specific bradycardia, to pregnant rats from gestational days 11-14. Embryonic heart rate and rhythm were determined using embryo culture. Cardiovascular function was assessed in surviving adult offspring at rest, during acute psychological stress (air jet stress, AJS), and after 7 days of repeated AJS. Dof reduced embryonic HR by 40% for ~8 h on each of the treatment days. On postnatal day 3, Dof offspring were ~10% smaller. Blood pressure was elevated in adult Dof rats (systolic blood pressure, night: 103.8 ± 3.9 vs. 111.2 ± 3.0 mmHg, P = 0.01). While the pressor response to AJS was similar in both groups (control 17.7 ± 3.4; Dof 18.9 ± 0.9 mmHg, P = 0.74), after 7 days repeated AJS, clear habituation was present in control (P = 0.0001) but not Dof offspring (P = 0.48). Only Dof offspring showed a small increase in resting blood pressure after 7 days repeated stress (+3.9 ± 1.7 mmHg, P = 0.05). The results indicate that embryonic bradycardia programs hypertension and impaired stress adaptation, and have implications for the maternal use of cardioactive drugs during pregnancy.
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Affiliation(s)
- Louise Prestipino
- School of Medical Sciences and Bosch InstituteSydney Medical SchoolThe University of SydneySydneyNSWAustralia
| | - Jaimie W. Polson
- School of Medical Sciences and Bosch InstituteSydney Medical SchoolThe University of SydneySydneyNSWAustralia
| | - Elisabeth Brolin
- School of Medical Sciences and Bosch InstituteSydney Medical SchoolThe University of SydneySydneyNSWAustralia
| | - Helen E. Ritchie
- School of Medical Sciences and Bosch InstituteSydney Medical SchoolThe University of SydneySydneyNSWAustralia
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Ritchie HE, Moore NP, Webster WS. Editor’s Highlight: Ethylene Glycol Teratogenicity: A Role for Embryonic Acidosis? Toxicol Sci 2017; 161:421-430. [DOI: 10.1093/toxsci/kfx225] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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Ang SY, Uebersohn A, Spencer CI, Huang Y, Lee JE, Ge K, Bruneau BG. KMT2D regulates specific programs in heart development via histone H3 lysine 4 di-methylation. Development 2016; 143:810-21. [PMID: 26932671 PMCID: PMC4813342 DOI: 10.1242/dev.132688] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
KMT2D, which encodes a histone H3K4 methyltransferase, has been implicated in human congenital heart disease in the context of Kabuki syndrome. However, its role in heart development is not understood. Here, we demonstrate a requirement for KMT2D in cardiac precursors and cardiomyocytes during cardiogenesis in mice. Gene expression analysis revealed downregulation of ion transport and cell cycle genes, leading to altered calcium handling and cell cycle defects. We further determined that myocardial Kmt2d deletion led to decreased H3K4me1 and H3K4me2 at enhancers and promoters. Finally, we identified KMT2D-bound regions in cardiomyocytes, of which a subset was associated with decreased gene expression and decreased H3K4me2 in mutant hearts. This subset included genes related to ion transport, hypoxia-reoxygenation and cell cycle regulation, suggesting that KMT2D is important for these processes. Our findings indicate that KMT2D is essential for regulating cardiac gene expression during heart development primarily via H3K4 di-methylation. Highlighted article: Cardiac-specific depletion of the H3K4 methyltransferase KMT2D causes dysregulation of genes associated with cell cycle regulation, ion homeostasis and hypoxia signaling.
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Affiliation(s)
- Siang-Yun Ang
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA 94158, USA Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Alec Uebersohn
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA 94158, USA
| | - C Ian Spencer
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA 94158, USA
| | - Yu Huang
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA 94158, USA
| | - Ji-Eun Lee
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kai Ge
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Benoit G Bruneau
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA Roddenberry Center for Stem Cell Biology and Medicine at Gladstone, San Francisco, CA 94158, USA Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94143, USA Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94143, USA
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Ritchie H, Oakes D, Hung TT, Hegedus E, Sood S, Webster W. The Effect of Dofetilide on the Heart Rate of GD11 and GD13 Rat Embryos, in vivo, Using Ultrasound. ACTA ACUST UNITED AC 2015; 104:196-203. [DOI: 10.1002/bdrb.21162] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 08/28/2015] [Indexed: 12/21/2022]
Affiliation(s)
- Helen Ritchie
- Discipline of Biomedical Science; University of Sydney; New South Wales Australia
| | - Diana Oakes
- Discipline of Biomedical Science; University of Sydney; New South Wales Australia
| | - Tzong-tyng Hung
- Biological Resources Imaging Laboratory; University of New South Wales; New South Wales Australia
| | - Elizabeth Hegedus
- Discipline of Biomedical Science; University of Sydney; New South Wales Australia
| | - Shreya Sood
- Discipline of Biomedical Science; University of Sydney; New South Wales Australia
| | - William Webster
- Department of Anatomy and Histology; The University of Sydney; New South Wales Australia
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Ritchie HE, Svensson CH, Nilsson MF, Webster WS. A comparison of drug-induced cardiotoxicity in rat embryos cultured in human serum or protein free media. J Pharmacol Toxicol Methods 2014; 70:276-82. [DOI: 10.1016/j.vascn.2014.07.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 07/07/2014] [Accepted: 07/23/2014] [Indexed: 10/25/2022]
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Nilsson MF, Webster WS. Effects of Macrolide Antibiotics on Rat Embryonic Heart Function In Vitro. ACTA ACUST UNITED AC 2014; 101:189-98. [DOI: 10.1002/bdrb.21107] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 02/15/2014] [Accepted: 02/16/2014] [Indexed: 11/08/2022]
Affiliation(s)
- Mats F. Nilsson
- Drug Safety and Toxicology; Department of Pharmaceutical Biosciences; Uppsala University; Uppsala Sweden
| | - William S. Webster
- Drug Safety and Toxicology; Department of Pharmaceutical Biosciences; Uppsala University; Uppsala Sweden
- Department of Anatomy and Histology; School of Medical Sciences; University of Sydney; Sydney Australia
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Nilsson MF, Ritchie H, Webster WS. The effect on rat embryonic heart rate of Na+, K+, and Ca2+ channel blockers, and the human teratogen phenytoin, changes with gestational age. ACTA ACUST UNITED AC 2013; 98:416-27. [PMID: 24323366 DOI: 10.1002/bdrb.21084] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 10/28/2013] [Accepted: 10/28/2013] [Indexed: 11/09/2022]
Abstract
In this study, we compared the effects of four ion channel blockers on rat embryonic heart function during the organogenic period from gestational day (GD) 10 to 15, to determine the changes in dependence on ion channels during rat cardiac development. Rat embryos in culture were exposed to either the human ether-á-go-go-related gene potassium channel blocker, dofetilide (400 nM); the sodium channel blocker, lidocaine (250 μM); the L-type calcium channel blocker, nifedipine (1.8 μM); or the multichannel blocker, phenytoin (200 μM). Lidocaine slowed the heart rate (HR) with the effect becoming more severe with increasing GD. Dofetilide slowed the embryonic HR and caused arrhythmias with the most severe effect on GD 11 to 13. Nifedipine primarily caused a negative inotropic effect except on GD 10 when it stopped the heart in most embryos. Phenytoin stopped the heart of most GD 10 to 12 embryos while on GD 13 to 15 phenytoin slowed the heart. The results demonstrate that as the rat heart develops during the organogenic period its functional dependence on ion channels changes markedly. These changes are important for understanding drug effects on the embryo during pregnancy and the methodology used provides a simple procedure for assessing drug effects on the developing heart.
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Affiliation(s)
- Mats F Nilsson
- Drug Safety and Toxicology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
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Comparative effects of sodium channel blockers in short term rat whole embryo culture. Toxicol Appl Pharmacol 2013; 272:306-12. [DOI: 10.1016/j.taap.2013.06.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 06/16/2013] [Accepted: 06/21/2013] [Indexed: 02/01/2023]
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Ritchie HE, Ababneh DH, Oakes DJ, Power CA, Webster WS. The teratogenic effect of dofetilide during rat limb development and association with drug-induced bradycardia and hypoxia in the embryo. ACTA ACUST UNITED AC 2013; 98:144-53. [PMID: 23504928 DOI: 10.1002/bdrb.21050] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 12/19/2012] [Indexed: 12/16/2022]
Abstract
BACKGROUND Dofetilide is an antiarrhythmic drug that blocks the cardiac repolarizing current IKr ((IKr, rapid component of the delayed rectifying potassium current). Previous studies have shown that (a) IKr is essential for normal cardiac function of the embryonic heart and (b) dofetilide is teratogenic in rodents. This study was undertaken to examine the mechanism by which dofetilide causes limb defects on gestational day 13 (GD 13) in the rat. METHODS Rats were treated with dofetilide (single oral dose, 5 mg/kg) on GD 13 and embryonic heart rates assessed by ultrasound (Vevo770, VisualSonics, Toronto, Ontario, Canada) 2 hr later. Fetuses were examined for malformations on GD 20. In a separate experiment, dofetilide treatment of GD 13 rats was followed 2, 4, 12, or 24 hr with iv dosing with the hypoxia marker, pimonidazole (60 mg/kg). Embryos were collected and heart rates were assessed in vitro and hypoxia in embryo limbs analyzed. RESULTS A teratogenic dose of dofetilide at a susceptible stage of development (GD 13) resulted in a period of bradycardia and arrhythmia of the embryonic heart and hypoxia in the developing limbs (GD 13) resulting in limb malformations (GD 20). CONCLUSIONS Drugs that induce periods of bradycardia and/or arrhythmia of the embryonic heart and cause the embryo to become hypoxic are potential human teratogens.
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Affiliation(s)
- Helen E Ritchie
- Discipline of Biomedical Science, Sydney Medical School, University of Sydney, Sydney, Australia
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Gunnström M, Ababneh D, Webster W, Oakes D, Ritchie H. Antipsychotic drugs cause bradycardia in GD 13 rat embryos in vitro. Reprod Toxicol 2012; 34:443-50. [DOI: 10.1016/j.reprotox.2012.06.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 05/30/2012] [Accepted: 06/15/2012] [Indexed: 10/28/2022]
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Ababneh D, Ritchie H, Webster WS. Antidepressants Cause Bradycardia and Heart Block in GD 13 Rat Embryos In Vitro. ACTA ACUST UNITED AC 2012; 95:184-93. [DOI: 10.1002/bdrb.21003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Deena Ababneh
- Department of Anatomy and Histology; Sydney Medical School; University of Sydney; Sydney; Australia
| | - Helen Ritchie
- Discipline of Biomedical Sciences,; Sydney Medical School; University of Sydney; Sydney; Australia
| | - William S. Webster
- Department of Anatomy and Histology; Sydney Medical School; University of Sydney; Sydney; Australia
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