Sertraline exposure leads to small left heart syndrome in adult mice

Maternal exposure to SSRIs or SNRIs and the risk of congenital abnormalities in offspring: A systematic review and meta-analysis

BACKGROUND

The association of maternal exposure to selective serotonin reuptake inhibitors (SSRIs) or serotonin and norepinephrine reuptake inhibitors (SNRIs) with the risk of system-specific congenital malformations in offspring remains unclear. We conducted a meta-analysis to examine this association and the risk difference between these two types of inhibitors.

METHODS

A literature search was performed from January 2000 to May 2023 using PubMed and Web of Science databases. Cohort and case-control studies that assess the association of maternal exposure to SSRIs or SNRIs with the risk of congenital abnormalities were eligible for the study.

RESULTS

Twenty-one cohort studies and seven case-control studies were included in the meta-analysis. Compared to non-exposure, maternal exposure to SNRIs is associated with a higher risk of congenital cardiovascular abnormalities (pooled OR: 1.64 with 95% CI: 1.36, 1.97), anomalies of the kidney and urinary tract (pooled OR: 1.63 with 95% CI: 1.21, 2.20), malformations of nervous system (pooled OR: 2.28 with 95% CI: 1.50, 3.45), anomalies of digestive system (pooled OR: 2.05 with 95% CI: 1.60, 2.64) and abdominal birth defects (pooled OR: 2.91 with 95%CI: 1.98, 4.28), while maternal exposure to SSRIs is associated with a higher risk of congenital cardiovascular abnormalities (pooled OR: 1.25 with 95%CI: 1.20, 1.30), anomalies of the kidney and urinary tract (pooled OR: 1.14 with 95%CI: 1.02, 1.27), anomalies of digestive system (pooled OR: 1.11 with 95%CI: 1.01, 1.21), abdominal birth defects (pooled OR: 1.33 with 95%CI: 1.16, 1.53) and musculoskeletal malformations (pooled OR: 1.44 with 95%CI: 1.32, 1.56).

CONCLUSIONS

SSRIs and SNRIs have various teratogenic risks. Clinicians must consider risk-benefit ratios and patient history when prescribing medicines.

Fetal cardiac safety of sertraline use during pregnancy

INTRODUCTION

Fetal cardiac safety of sertraline is controversial even though it is among the most frequently used antidepressants in pregnancy. Sertraline could theoretically affect the fetal heart resulting in malformations or more subtle changes, but studies evaluating fetal cardiac safety are prone to a number of systematic and random errors.

AREAS COVERED

The objective of this review is to evaluate the fetal cardiac safety profile of sertraline in pregnancy. A literature review included articles until November 2022 in Medline with no time or language limitations.

EXPERT OPINION

Sertraline is associated with septal heart malformations, but not with more severe heart malformations. The association may be causal or at least partly related to systematic errors, including confounding by indication. Regardless of the causal mechanism, the association should not limit well-indicated treatments of maternal depression. The few available studies on fetal heart function is reassuring. There are no human data on the long-term effects on offspring cardiac function, but the teratogenic and fetal heart function studies do not imply risks of any major cardiac problems later in life. Interactions with other medication may, however, alter the risks associated with any medication in pregnancy, and information and surveilence systems taking this into account is much needed.

Hypersensitivity of Zebrafish htr2b Mutant Embryos to Sertraline Indicates a Role for Serotonin Signaling in Cardiac Development

ABSTRACT

Selective serotonin reuptake inhibitors (SSRIs) are antidepressants prescribed in 10% of pregnancies in the United States. Maternal use of SSRIs has been linked to an elevated rate of congenital heart defects, but the exact mechanism of pathogenesis is unknown. Previously, we have shown a decrease in cardiomyocyte proliferation, left ventricle size, and reduced cardiac expression of the serotonin receptor 5-HT 2B in offspring of mice exposed to the SSRI sertraline during pregnancy, relative to offspring of untreated mice. These results suggest that disruption of serotonin signaling leads to heart defects. Supporting this conclusion, we show here that zebrafish embryos exposed to sertraline develop with a smaller ventricle, reduced cardiomyocyte number, and lower cardiac expression of htr2b relative to untreated embryos. Moreover, zebrafish embryos homozygous for a nonsense mutation of htr2b ( htr2bsa16649 ) were sensitized to sertraline treatment relative to wild-type embryos. Specifically, the ventricle area was reduced in the homozygous htr2b mutants treated with sertraline compared with wild-type embryos treated with sertraline and homozygous htr2b mutants treated with vehicle control. Whereas long-term effects on left ventricle shortening fraction and stroke volume were observed by echocardiography in adult mice exposed to sertraline in utero, echocardiograms of adult zebrafish exposed to sertraline as embryos were normal. These results implicate the 5-HT 2B receptor functions in heart development and suggest zebrafish are a relevant animal model that can be used to investigate the connection between maternal SSRI use and elevated risk of congenital heart defects.

Effect of Low and High Doses of Two Selective Serotonin Reuptake Inhibitors on Pregnancy Outcomes and Neonatal Mortality

Selective serotonin reuptake inhibitors (SSRI) are the most common antidepressant used by pregnant women; however, they have been associated with adverse pregnancy outcomes and perinatal morbidity in pregnant women and animal models. We investigated the effects of two SSRI, fluoxetine and sertraline, on pregnancy and neonatal outcomes in mice. Wild-type mice were treated daily with low and high doses of fluoxetine (2 and 20 mg/kg) and sertraline (10 and 20 mg/kg) from the day of detection of a vaginal plug until the end of lactation (21 days postpartum). Pregnancy rate was decreased only in the high dose of fluoxetine group. Maternal weight gain was reduced in the groups receiving the high dose of each drug. Number of pups born was decreased in the high dose of fluoxetine and low and high doses of sertraline while the number of pups weaned was decreased in all SSRI-treated groups corresponding to increased neonatal mortality in all SSRI-treated groups. In conclusion, there was a dose-dependent effect of SSRI on pregnancy and neonatal outcomes in a non-depressed mouse model. However, the distinct placental transfer of each drug suggests that the effects of SSRI on pup mortality may be mediated by SSRI-induced placental insufficiency rather than a direct toxic effect on neonatal development and mortality.

Selective serotonin reuptake inhibitors ameliorate MEGF10 myopathy

MEGF10 myopathy is a rare inherited muscle disease that is named after the causative gene, MEGF10. The classic phenotype, early onset myopathy, areflexia, respiratory distress and dysphagia, is severe and immediately life-threatening. There are no disease-modifying therapies. We performed a small molecule screen and follow-up studies to seek a novel therapy. A primary in vitro drug screen assessed cellular proliferation patterns in Megf10-deficient myoblasts. Secondary evaluations were performed on primary screen hits using myoblasts derived from Megf10-/- mice, induced pluripotent stem cell-derived myoblasts from MEGF10 myopathy patients, mutant Drosophila that are deficient in the homologue of MEGF10 (Drpr) and megf10 mutant zebrafish. The screen yielded two promising candidates that are both selective serotonin reuptake inhibitors (SSRIs), sertraline and escitalopram. In depth follow-up analyses demonstrated that sertraline was highly effective in alleviating abnormalities across multiple models of the disease including mouse myoblast, human myoblast, Drosophila and zebrafish models. Sertraline also restored deficiencies of Notch1 in disease models. We conclude that SSRIs show promise as potential therapeutic compounds for MEGF10 myopathy, especially sertraline. The mechanism of action may involve the Notch pathway.

Sertraline use during pregnancy and effect on fetal cardiac function

Objectives: The objective of this study was to evaluate the fetal cardiac function in human pregnancies exposed to sertraline (a selective serotonin reuptake inhibitor) compared to unexposed pregnancies.Method: We included 44 women in gestational week 25 + 0 days to week 26 + 6 days. Fifteen women used sertraline (50-150 mg per day), and 29 women used no daily medication. We assessed fetal cardiac function by Myocardial Performance Index (MPI), E/A ratios and by tricuspid and mitral annular plane systolic excursion (TAPSE and MAPSE) measured by 2D M-mode and by 4D eSTIC M-mode.Results: There were no differences between the sertraline exposed and the unexposed. The mean difference of MPI was 0.03 (95% CI -0.08-0.03), of tricuspid and mitral E/A ratios 0.00 (95% CI -0.03-0.05) and 0.03 (95% CI -0.07-0.01), respectively. The mean difference of TAPSE, by 2D and eSTIC, was 0.07 mm (95% CI -0.56-0.41) and 0.10 mm (95% CI -0.55-0.34). Mean difference of MAPSE, by 2D and eSTIC was 0.16 mm (95% CI -0.22-0.53) and 0.24 mm (95% CI -0.16-0.65), respectively. Serum levels of sertraline in exposed participants ranged from 33-266, median 92 nmol/L.Conclusions: We found no significant differences in fetal cardiac function, assessed by TAPSE, MAPSE, MPI and E/A ratios, in pregnancies exposed to sertraline compared to the unexposed.

Assessing SSRIs' effects on fetal cardiomyocytes utilizing placenta-fetus model

Selective serotonin reuptake inhibitors (SSRIs) have been shown to hinder cardiomyocyte signaling, raising concerns about their safety during pregnancy. Approaches to assess SSRI-induced effects on fetal cardiovascular cells following passage of drugs through the placental barrier in vitro have only recently become available. Herein, we report that the SSRIs, fluoxetine and sertraline, lead to slowed cardiomyocyte calcium oscillations and induce increased secretion of troponin T and creatine kinase-MB with reduced secretion of NT-proBNP, three key cardiac injury biomarkers. We show the cardiomyocyte calcium handling effects are further amplified following indirect exposure through a placental barrier model. These studies are the first to investigate the effects of placental barrier co-culture with cardiomyocytes in vitro and to show cardiotoxicity of SSRIs following passage through the placental barrier. STATEMENT OF SIGNIFICANCE: Use of selective serotonin reuptake inhibitors (SSRIs), a class of antidepressants, during pregnancy continues to rise despite multiple studies showing potential for detrimental effects on the developing fetus. SSRIs are particularly thought to slow cardiovascular electrical activity, such as ion signaling, yet few, if any, methods exist to rigorously study these drug-induced effects on human pregnancy and the developing fetus. Within this study, we utilized a placenta-fetus model to evaluate these drug-induced effects on cardiomyocytes, looking the drugs' effects on calcium handling and secretion of multiple cardiac injury biomarkers. Together, with existing literature, this study provides a platform for assessing pharmacologic effects of drugs on cells mimicking the fetus and the role the placenta plays in this process.

Use of Prescribed Psychotropics during Pregnancy: A Systematic Review of Pregnancy, Neonatal, and Childhood Outcomes

This paper reviews the findings from preclinical animal and human clinical research investigating maternal/fetal, neonatal, and child neurodevelopmental outcomes following prenatal exposure to psychotropic drugs. Evidence for the risks associated with prenatal exposure was examined, including teratogenicity, neurodevelopmental effects, neonatal toxicity, and long-term neurobehavioral consequences (i.e., behavioral teratogenicity). We conducted a comprehensive review of the recent results and conclusions of original research and reviews, respectively, which have investigated the short- and long-term impact of drugs commonly prescribed to pregnant women for psychological disorders, including mood, anxiety, and sleep disorders. Because mental illness in the mother is not a benign event, and may itself pose significant risks to both mother and child, simply discontinuing or avoiding medication use during pregnancy may not be possible. Therefore, prenatal exposure to psychotropic drugs is a major public health concern. Decisions regarding drug choice, dose, and duration should be made carefully, by balancing severity, chronicity, and co-morbidity of the mental illness, disorder, or condition against the potential risk for adverse outcomes due to drug exposure. Globally, maternal mental health problems are considered as a major public health challenge, which requires a stronger focus on mental health services that will benefit both mother and child. More preclinical and clinical research is needed in order to make well-informed decisions, understanding the risks associated with the use of psychotropic medications during pregnancy.

Model Placental Barrier Phenotypic Response to Fluoxetine and Sertraline: A Comparative Study

Medications taken during pregnancy may significantly impact fetal development, yet there are few studies that rigorously assess medication safety due to ethical concerns. Selective serotonin reuptake inhibitors (SSRIs) are a class of drug increasingly being prescribed for depression, yet multiple studies have shown that taking SSRIs during pregnancy can lead to preterm birth and potential health concerns for the baby. Therefore, a biomimetic placental barrier model is utilized herein to assess transport profiles and phenotypic effects resulting from SSRI exposure, comparing fluoxetine and sertraline. Results show that the placental barrier quickly uptakes drug from the maternal side, but slowly releases on the fetal side. Phenotypically, there is a dose-dependent change in cell adhesion molecule (CAM) and transforming growth factor beta (TGFβ) secretions, markers of cell adhesion and angiogenesis. Both drugs impact CAM secretions, whereas sertraline alone impacts TGFβ secretions. When evaluating cell type, it becomes clear that endothelial cells, not trophoblast, are the main cell type involved in these phenotypic changes. Overall, these findings further the understanding of SSRI transplacental transport and drug-induced effects on the placental barrier.

A Prospective Study Evaluating the Effects of SSRI Exposure on Cardiac Size and Function in Newborns

BACKGROUND

Selective serotonin reuptake inhibitors (SSRIs) are antidepressants prescribed in 10% of pregnancies in the USA. We have previously shown in preclinical studies that sertraline exposure impacts cardiomyocyte development, leading to reductions in left ventricular size and cardiac function.

OBJECTIVES

We hypothesized that in utero SSRI exposure will lead to reduced left ventricular dimensions and cardiac function on echocardiography immediately after birth.

METHODS

Twenty term infants with and 21 term infants without in utero exposure to SSRIs underwent echocardiograms to assess cardiac size and function. The exclusion criteria for infants were prematurity, small or large for gestational age, any respiratory or cardiovascular support needed after birth, and any major congenital malformation.

RESULTS

Infants exposed to in utero SSRIs had significantly reduced right ventricular dimensions in the diastole (controls 1.0 cm [0.86, 1.20], SSRI 0.89 cm [0.730, 1.05], p = 0.03), and left ventricular lengths in the diastole and systole (diastole: controls 3.4 cm [3.25, 3.65], SSRI 3.25 cm [3.10, 3.45], p = 0.03; systole: controls 2.9 cm [2.65, 3.05], SSRI 2.6 cm [2.50, 2.85], p = 0.01). No differences were observed in cardiac function. Importantly, there were no differences in maternal conditions or infant birth weight, body surface area, or gestational age.

CONCLUSIONS

Our findings suggest an association between in utero exposure to SSRIs and ventricular size in infants. Given the increasing use of SSRIs during pregnancy and the importance of early life programming on future cardiovascular health, larger studies need to be completed to determine if in utero SSRI exposure impacts ventricular size.

Neonatal Growth Restriction Slows Cardiomyocyte Development and Reduces Adult Heart Size

Prematurity is associated with reduced cardiac dimensions and an increased risk of cardiovascular disease. While prematurity is typically associated with ex utero neonatal growth restriction (GR), the independent effect of neonatal GR on cardiac development has not been established. We tested the hypothesis that isolated neonatal GR decreases cardiomyocyte growth and proliferation, leading to long-term alterations in cardiac morphology. C57BL/6 mice were fostered in litters ranging in size from 6 to 12 pups to accentuate normal variation in neonatal growth. Regardless of litter size, GR was defined by a weight below the 10th percentile. On postnatal day 8, Ki67 immunoreactivity, cardiomyocyte nucleation status and cardiomyocyte profile area were assessed. For adult mice, cardiomyocyte area was determined, along with cardiac dimensions by echocardiography and cardiac fibrosis by Masson's trichrome stain. On day 8, cardiomyocytes from GR versus control mice were significantly smaller and less likely to be binucleated with evidence of persistent cell cycle activity. As adults, GR mice continued to have smaller cardiomyocytes, as well as decreased left ventricular volumes without signs of fibrosis. Neonatal GR reduces cardiomyocyte size, delays the completion of binucleation, and leads to long-term alterations in cardiac morphology. Clinical studies are needed to ascertain whether these results translate to preterm infants that must continue to grow and mature in the midst of the increased circulatory demands that accompany their premature transition to an ex utero existence. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc.

Cardiac Outcomes After Perinatal Sertraline Exposure in Mice

Selective serotonin reuptake inhibitors are prescribed to 6%-10% of pregnant women in the United States. Using an intrauterine plus neonatal exposure model to represent exposure throughout human pregnancy, we hypothesized sertraline exposure would impact intracardiac serotonin signaling and lead to small left heart syndrome in the absence of maternal psychopathology. C57BL/6 adult female mice received sertraline (5 mg·kg·d IP) or saline throughout pregnancy to time of delivery. Pups maintained exposure on postnatal days 1-14 to encompass the developmental window analogous to human gestation. Sertraline-exposed mice had increased cardiac hydroxyproline content, decreased 5-HT2B receptor mRNA levels, and increased 5-HT2A receptor and serotonin transporter mRNA levels on postnatal day 21 (P < 0.05). These changes were associated with diminished exercise capacity at 6 weeks (P < 0.05) and decreased adult shortening fraction and stroke volume at 5 months. Isolated cardiomyocytes from neonatal sertraline-exposed mice had significantly decreased proliferation, cross-sectional area, and phosphorylation of Akt (P < 0.05 vs. neonatal control mice). Perinatal sertraline exposure alters neonatal cardiac development and produces long-standing changes in adult cardiac function and exercise capacity. Further studies are needed to assess whether similar findings are present in the growing population that has been exposed to selective serotonin reuptake inhibitors during development.

Perinatal SSRI exposure permanently alters cerebral serotonin receptor mRNA in mice but does not impact adult behaviors

PURPOSE

Associations have been made between maternal selective serotonin reuptake inhibitor (SSRI) use during pregnancy and altered behavior in offspring, including an increased risk of autism. Given the important role serotonin plays in behavior, we hypothesized SSRI exposure in the perinatal period would alter central serotonin receptor expression and program adult behaviors in mice.

METHODS

Female mice were injected with sertraline or saline throughout pregnancy. Offspring continued to receive injections on postnatal days 1-14, a time period in mice similar to the third trimester in human pregnancy. Adult offspring underwent behavioral testing, and serotonin receptor mRNA levels were quantified.

RESULTS

Compared to controls, SSRI exposed mice did not have a reduction in social interactions, spatial learning, or exploratory behavior. As adults, sertraline exposed mice had significantly increased mRNA levels of multiple 5-HT receptors, serotonin transporter (5-HTT), and tryptophan hydroxylase isoform 2 in the cerebral cortex.

CONCLUSION

Although no behavioral phenotype was observed, SSRI exposure in the perinatal period permanently alters cerebral receptor mRNA levels. We speculate these shifts in mRNA expression provide important compensation during SSRI exposure. Further pre-clinical and clinical investigation into additional serotonin-regulated phenotypes is necessary to further assess the long-term implications of perinatal SSRI exposure.

Selective serotonin reuptake inhibitor exposure constricts the mouse ductus arteriosus in utero

Use of selective serotonin reuptake inhibitors (SSRIs) is common during pregnancy. Fetal exposure to SSRIs is associated with persistent pulmonary hypertension of the newborn (PPHN); however, a direct link between the two has yet to be established. Conversely, it is well known that PPHN can be caused by premature constriction of the ductus arteriosus (DA), a fetal vessel connecting the pulmonary and systemic circulations. We hypothesized that SSRIs could induce in utero DA constriction. Using isolated vessels and whole-animal models, we sought to determine the effects of two commonly prescribed SSRIs, fluoxetine and sertraline, on the fetal mouse DA. Cannulated vessel myography studies demonstrated that SSRIs caused concentration-dependent DA constriction and made vessels less sensitive to prostaglandin-induced dilation. Moreover, in vivo studies showed that SSRI-exposed mice had inappropriate DA constriction in utero. Taken together, these findings establish that SSRIs promote fetal DA constriction and provide a potential mechanism by which SSRIs could contribute to PPHN.

Oral oestrogen reverses ovariectomy-induced morning surge hypertension in growth-restricted mice

Perinatal growth restriction (GR) is associated with heightened sympathetic tone and hypertension. We have previously shown that naturally occurring neonatal GR programmes hypertension in male but not female mice. We therefore hypothesized that intact ovarian function or post-ovariectomy (OVX) oestrogen administration protects GR female mice from hypertension. Utilizing a non-interventional model that categorizes mice with weanling weights below the tenth percentile as GR, control and GR adult mice were studied at three distinct time points: baseline, post-OVX and post-OVX with oral oestrogen replacement. OVX elicited hypertension in GR mice that was significantly exacerbated by psychomotor arousal (systolic blood pressure at light to dark transition: control 122 ± 2; GR 119 ± 2; control-OVX 116 ± 3; GR-OVX 126 ± 3 mmHg). Oestrogen partially normalized the rising blood pressure surge seen in GR-OVX mice (23 ± 7% reduction). GR mice had left ventricular hypertrophy, and GR-OVX mice in particular had exaggerated bradycardic responses to sympathetic blockade. For GR mice, a baseline increase in baroreceptor reflex sensitivity and high frequency spectral power support a vagal compensatory mechanism, and that compensation was lost following OVX. For GR mice, the OVX-induced parasympathetic withdrawal was partially restored by oestrogen (40 ± 25% increase in high frequency spectral power, P<0.05). In conclusion, GR alters cardiac morphology and cardiovascular regulation. The haemodynamic consequences of GR are attenuated in ovarian-sufficient or oestrogen-replete females. Further investigations are needed to define the role of hormone replacement therapy targeted towards young women with oestrogen deficiency and additional cardiovascular risk factors, including perinatal GR, cardiac hypertrophy and morning surge hypertension.

Transient postnatal fluoxetine decreases brain concentrations of 20-HETE and 15-epi-LXA4, arachidonic acid metabolites in adult mice

BACKGROUND

Transient postnatal exposure of rodents to the selective serotonin (5-HT) reuptake inhibitor (SSRI) fluoxetine alters behavior and brain 5-HT neurotransmission during adulthood, and also reduces brain arachidonic (ARA) metabolic consumption and protein level of the ARA metabolizing enzyme, cytochrome P4504A (CYP4A).

HYPOTHESIS

Brain 20-hydroxyeicosatetraenoic acid (20-HETE), converted by CYP4A from ARA, will be reduced in adult mice treated transiently and postnatally with fluoxetine.

METHODS

Male mice pups were injected i.p. daily with fluoxetine (10mg/kg) or saline during P4-P21. At P90 their brain was high-energy microwaved and analyzed for 20-HETE and six other ARA metabolites by enzyme immunoassay.

RESULTS

Postnatal fluoxetine vs. saline significantly decreased brain concentrations of 20-HETE (-70.3%) and 15-epi-lipoxin A4 (-60%) in adult mice, but did not change other eicosanoid concentrations.

CONCLUSIONS

Behavioral changes in adult mice treated postnatally with fluoxetine may be related to reduced brain ARA metabolism involving CYP4A and 20-HETE formation.

Effects of neonatal fluvoxamine administration on the physical development and activity of the serotoninergic system in white rats

Selective serotonin reuptake inhibitors (SSRIs), including fluvoxamine, are widely used to treat depressive disorders in pregnant women. These antidepressants effectively penetrate through the placental barrier, affecting the fetus during the critical phase of neurodevelopment. Some clinical studies have linked prenatal exposure to SSRIs with increased neonatal mortality, premature birth, decreased fetal growth and delay in psychomotor development. However, the effects of prenatal exposure to SSRIs remain unknown. The administration of SSRIs in rodents during the first postnatal weeks is considered as an model for studying the effects of prenatal SSRIs exposure in human. The aim of this work was to study the acute effects of chronic fluvoxamine (FA) administration in white rat pups. The study was carried out in male and female rat pups treated with FA (10 mg/kg/day, intraperitoneally) from postnatal days 1 to 14. The lethality level, body weight, age of eye opening, and motor reflex maturation were recorded. The contents of biogenic amines and their metabolites in different brain structures were also determined. It was shown that neonatal FA administration led to increased lethality level, reduced body weight, and delayed maturation of motor reflexes. Furthermore, increased noradrenalin level in hypothalamus, serotonin level in hippocampus and serotonin metabolite 5-HIAA level in frontal cortex, hypothalamus, hippocampus, and striatum were observed in drug-treated animals compared to the control group. We can conclude that the altered activity of the serotoninergic system induced by fluvoxamine administration at early developmental stages leads to a delay in physical and motor development.

Impact of neonatal sertraline exposure on the post-myocardial infarction outcomes of adult male mice

Neonatal exposure to a selective serotonin reuptake inhibitor (SSRI) leads to decreased left ventricular volumes and sympathetic activation in adult mice. We hypothesized this neonatal SSRI exposure-induced small left heart syndrome would increase post-myocardial infarction (MI) morbidity and mortality. C57BL/6 mice received saline or sertraline (5 mg/kg intraperitoneally) on postnatal days 1-14. At 5 months, male mice underwent coronary artery ligation and were monitored by radiotelemetry until death or 4 weeks after ligation. After ligation, SSRI-exposed mice had increased heart rates (SSRI, 516 ± 13 bpm; control, 470 ± 15 bpm; P < 0.05). SSRI-exposed mice had significant reductions in left ventricular systolic volumes both before and after coronary ligation (SSRI: baseline = 20 ± 3 μL, post-MI = 37 ± 10 μL; control: baseline = 30 ± 3 μL, post-MI = 65 ± 23 μL). Post-MI echocardiography showed significantly decreased ejection fraction in control mice (baseline = 60% ± 4%, post-MI = 41% ± 2%, P < 0.01) but not the SSRI-exposed mice (baseline = 65% ± 3%, post-MI = 53% ± 7%). Neonatal SSRI exposure did not significantly alter post-MI survival. We conclude that the preexisting SSRI-induced small left heart syndrome may provide protection from post-MI ventricular dilation.

Reduced blood pressure of CFTR-F508del carriers correlates with diminished arterial reactivity rather than circulating blood volume in mice

The F508del mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) is the most common cause of cystic fibrosis (CF). Both CF patients and F508del carriers have decreased blood pressure. While this has been attributed to salt depletion, recent studies have shown F508del expression interferes with smooth muscle cell calcium mobilization. We tested the hypothesis that carriers of the F508del mutation have lower adult blood pressures and reduced aortic contractility without a reduction in circulating blood volume. By radiotelemetry, F508del heterozygous mice had significantly lower arterial pressures than wild-type C57BL/6 controls, with the greatest effect seen at the time of dark-to-light cycle transition (mean difference of 10 mmHg). To replicate the vascular effects of sympathetic arousal, isoproterenol and epinephrine were co-infused, and F508del mice again had significantly reduced arterial pressures. Aortas isolated from F508del heterozygous mice had significantly decreased constriction to noradrenaline (0.9±0.2 versus 2.9±0.7 mN). Inhibition of wild-type CFTR or the inositol triphosphate receptor replicated the phenotype of F508del aortas. CFTR carrier status did not alter circulating blood volume. We conclude the CFTR-F508del mutation decreases aortic contractility and lowers arterial pressures. As a cAMP-activated chloride channel that facilitates calcium mobilization, we speculate wild-type CFTR co-activation during adrenergic receptor stimulation buffers the vasodilatory response to catecholamines, and loss of this compensatory vasoconstrictor tone may contribute to the lower arterial pressures seen in heterozygote carriers of a CFTR-F508del mutation.

Transient postnatal fluoxetine leads to decreased brain arachidonic acid metabolism and cytochrome P450 4A in adult mice

Fetal and perinatal exposure to selective serotonin (5-HT) reuptake inhibitors (SSRIs) has been reported to alter childhood behavior, while transient early exposure in rodents is reported to alter their behavior and decrease brain extracellular 5-HT in adulthood. Since 5-HT2A/2C receptor-mediated neurotransmission can involve G-protein coupled activation of cytosolic phospholipase A2 (cPLA2), releasing arachidonic acid (ARA) from synaptic membrane phospholipid, we hypothesized that transient postnatal exposure to fluoxetine would alter brain ARA metabolism in adult mice. Brain ARA incorporation coefficients k* and rates Jin were quantitatively imaged following intravenous [1-(14)C]ARA infusion of unanesthetized adult mice that had been injected daily with fluoxetine (10mg/kg i.p.) or saline during postnatal days P4-P21. Expression of brain ARA metabolic enzymes and other relevant markers also was measured. On neuroimaging, k* and Jin was decreased widely in early fluoxetine- compared to saline-treated adult mice. Of the enzymes measured, cPLA2 activity was unchanged, while Ca(2+)-independent iPLA2 activity was increased. There was a significant 74% reduced protein level of cytochrome P450 (CYP) 4A, which can convert ARA to 20-HETE. Reduced brain ARA metabolism in adult mice transiently exposed to postnatal fluoxetine, and a 74% reduction in CYP4A protein, suggest long-term effects independent of drug presence in brain ARA metabolism, and in CYP4A metabolites. These changes might contribute to reported altered behavior following early SSRI in rodents.

The effects of maternal depression and maternal selective serotonin reuptake inhibitor exposure on offspring

It has been estimated that 20% of pregnant women suffer from depression and it is well-documented that maternal depression can have long-lasting effects on the child. Currently, common treatment for maternal depression has been the selective serotonin reuptake inhibitor medications (SSRIs) which are used by 2–3% of pregnant women in the Nordic countries and by up to 10% of pregnant women in the United States. Antidepressants cross the placenta and are transferred to the fetus, thus, the question arises as to whether children of women taking antidepressants are at risk for altered neurodevelopmental outcomes and, if so, whether the risks are due to SSRI medication exposure or to the underlying maternal depression. This review considers the effects of maternal depression and SSRI exposure on offspring development in both clinical and preclinical populations. As it is impossible in humans to study the effects of SSRIs without taking into account the possible underlying effects of maternal depression (healthy pregnant women do not take SSRIs), animal models are of great value. For example, rodents can be used to determine the effects of maternal depression and/or perinatal SSRI exposure on offspring outcomes. Unraveling the joint (or separate) effects of maternal depression and SSRI exposure will provide more insights into the risks or benefits of SSRI exposure during gestation and will help women make informed decisions about using SSRIs during pregnancy.

Placental serotonin: implications for the developmental effects of SSRIs and maternal depression

In addition to its role in the pathophysiology of numerous psychiatric disorders, increasing evidence points to serotonin (5-HT) as a crucial molecule for the modulation of neurodevelopmental processes. Recent evidence indicates that the placenta is involved in the synthesis of 5-HT from maternally derived tryptophan (TRP). This gives rise to the possibility that genetic and environmental perturbations directly affecting placental TRP metabolism may lead to abnormal brain circuit wiring in the developing embryo, and therefore contribute to the developmental origin of psychiatric disorders. In this review, we discuss how perturbations of the placental TRP metabolic pathway may lead to abnormal brain development and function throughout life. Of particular interest is prenatal exposure to maternal depression and antidepressants, both known to alter fetal development. We review existing evidence on how antidepressants can alter placental physiology in its key function of maintaining fetal homeostasis and have long-term effects on fetal forebrain development.