Rorabaugh BR, Seeley SL, Bui AD, Sprague L, D'Souza MS. Prenatal methamphetamine differentially alters myocardial sensitivity to ischemic injury in male and female adult hearts. Am J Physiol Heart Circ Physiol 310: H516 -H523, 2016. First published December 18, 2015 doi:10.1152/ajpheart.00642.2015-Methamphetamine is one of the most common illicit drugs abused during pregnancy. The neurological effects of prenatal methamphetamine are well known. However, few studies have investigated the potential effects of prenatal methamphetamine on adult cardiovascular function. Previous work demonstrated that prenatal cocaine exposure increases sensitivity of the adult heart to ischemic injury. Methamphetamine and cocaine have different mechanisms of action, but both drugs exert their effects by increasing dopaminergic and adrenergic receptor stimulation. Thus the goal of this study was to determine whether prenatal methamphetamine also worsens ischemic injury in the adult heart. Pregnant rats were injected with methamphetamine (5 mg·kg Ϫ1 ·day Ϫ1 ) or saline throughout pregnancy. When pups reached 8 wk of age, their hearts were subjected to ischemia and reperfusion by means of a Langendorff isolated heart system. Prenatal methamphetamine had no significant effect on infarct size, preischemic contractile function, or postischemic recovery of contractile function in male hearts. However, methamphetamine-treated female hearts exhibited significantly larger infarcts and significantly elevated enddiastolic pressure during recovery from ischemia. Methamphetamine significantly reduced protein kinase Cε expression and Akt phosphorylation in female hearts but had no effect on these cardioprotective proteins in male hearts. These data indicate that prenatal methamphetamine differentially affects male and female sensitivity to myocardial ischemic injury and alters cardioprotective signaling proteins in the adult heart. prenatal methamphetamine; ischemia; heart; pregnancy; drug abuse NEW & NOTEWORTHY Prenatal exposure to methamphetamine increases myocardial sensitivity to ischemic injury and alters proteins involved in cardioprotective signaling pathways in the adult female rat heart. These changes were not observed in male hearts. The responses of adult male and female hearts to an ischemic insult are differentially altered by prenatal methamphetamine.METHAMPHETAMINE is one of the most common illicit drugs abused during pregnancy (2, 29). One study found that 5.2% of pregnant women use methamphetamine at some point during their pregnancy (2). Most studies of prenatal methamphetamine have focused on the impact of this drug on behavior and cognitive effects during early childhood. Prenatal methamphetamine produces a variety of neurological effects, including structural changes in the brain (8, 37), increased prevalence of cognitive and behavioral problems (11, 23), delayed development of gross motor skills (42), and decreased verbal and spatial memory (8). In contrast to these neurological effects, the impact of prenatal methamphetamin...

This study assessed the role of regulator of G protein signaling 2 (RGS2) in nicotine-induced anxiolytic- and antidepressant-like effects using RGS2 wildtype (WT) and RGS2 knockout (KO) mice. RGS2 negatively regulates monoaminergic neurotransmission, which is implicated in the pathology of anxiety and depression. We hypothesized that deletion of RGS2 would enhance nicotine-induced anxiolytic- and antidepressant-like effects, which were assessed using the elevated plus maze and tail suspension tests, respectively. Anxiolytic-like effects were observed in both RGS2 WT and KO mice after administration of low dose of nicotine (0.05 mg/kg, base) compared to respective saline controls. Additionally, administration of nicotine (0.1 mg/kg, base) compared to saline resulted in anxiolytic-like effects in RGS2 KO mice, but not RGS2 WT mice, suggesting genetic deletion of RGS2 facilitated anxiolytic-like effects of nicotine. Administration of nicotine (0.5 and 1 mg/kg, base) compared to saline resulted in antidepressant-like effects in RGS2 WT mice. Antidepressant-like effects were observed in RGS2 KO mice only at the highest tested dose of nicotine (1 mg/kg, base) compared to saline controls, suggesting that genetic deletion of RGS2 decreased sensitivity to antidepressant-like effects of nicotine. Together, the data suggest that RGS2 differentially regulated nicotine-induced affective behavioral responses. These data suggest that individuals with RGS2 polymorphisms may experience differential affective responses to tobacco smoking, which may make them vulnerable to developing nicotine addiction.

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