Effects Of Maternal Exposure To Nicotine During Pregnancy On Fetal And Offspring Arrhythmia

PART 1 Effects of maternal exposure to nicotine during late gestation on fetal values, heart rate, and arrhythmiaObjective: To determine the effects of different doses of nicotine in ewes on fetal blood values,heart rate,and arrhythmia during late term.Methods: Chronically prepared ovine fetal model under conscious and unstressed condition. Pregnant ewes were administered 0.9%NaCl, or 10ug/kg and 25ug/kg nicotine, 15 minute later maternal and fetal blood gas were detected by blood gas analyzer, plasma osmotic pressure was tested by osmotic pressure machine; Maternal and fetal heart rate were recorded by power lab, arrhythmia was analyzed by the cardiac cycle.Results: Maternal and fetal blood gas, blood values were not changed after pregnant ewes were administered nicotine. Fetal blood values were also not changed, but fetal PO2 and pH decreased, PCO2 was increased in the nicotine treated fetus. Arrhythmia in nicotine treated group was also increased. Conclusion: Fetal arrhythmia was increased in exposure to nicotine at doses of 10ug/kg and 25ug/kg.PART 2 Effects of maternal exposure to nicotine on fetal blood values and male offspring heart rate and arrhythmiaObjective: To determine the effects of maternal exposure to nicotine during gestation on offspring arrhythmia.Methods: Pregnant rats were subcutaneous injected with nicotine 1.5mg/kg.d from G1 to G21, Blood electrolyte, blood gas and plasma osmotic pressure at G21 (maternal and fetal rats) were determined. Weight of fetal heart and fetal body were measured. Male offspring at 4-5 month old were used. Their blood values, heart weight and body weight were measured. Electrocardiogram machine was used to determine heart rate and arrhythmia while rats were restricted and after administration of nicotine.Results: Fetal blood electrolyte was not changed, but fetal PO2, pH, and heart weight decreased, PCO2 increased; Prenatal nicotine had no effects on blood gas, blood electrolyte, body and heart weight in male adult offspring. However, in offspring exposured to prenatal nicotine, basic heart rate was increased with restriction and arrhythmia was increased in response to injection of nicotine.Conclusion: Basic heart rate was higher in the offspring exposured to prenatal nicotine, and arrhythmia was increased in response to injection of nicotine.