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404: Transplacental transfer and distribution of bupropion
SMFM Abstracts
www.AJOG.org 401
THROMBIN SUPPRESSES HCG PRODUCTION BY HUMAN SYNCYTIOTROPHOBLAST: A MECHANISM BY WHICH FIRST TRIMESTER BLEEDING CAUSES ABORTION VICTORIA SNEGOVSKIKH1, ERIC HODGSON1, ANNA SFAKIANAKI1, EDMUND FUNAI1, YUEHONG MA1, SETH GULLER1, MIZANUR RAHMAN1, CATALIN BUHIMSCHI1, IRINA BUHIMSCHI1, ERROL NORWITZ1, 1Yale University, New Haven, Connecticut OBJECTIVE: Bleeding in the first trimester is associated with spontaneous pregnancy loss, but whether this bleeding causes the abortion or is simply a sign of an already unsuccessful implantation is not clear. Adequate production of hCG by syncytiotrophoblast is critical to the maintenance of early pregnancy by sustaining progesterone production by the corpus luteum. We propose that bleeding may cause abortion by interfering with hCG-progesterone signalling. This study investigates the effect of thrombin on hCG production by syncytiotrophoblast in vitro. STUDY DESIGN: Term placentae were collected from elective cesarean deliveries and cytotrophoblast cells isolated by enzymatic digestion and purified using Percoll gradient. As previously described, cells were cultured in Basal Dulbecco’s medium containing 5% fetal calf serum for 3-4 days at which time syncytiotrophoblast formation was evident. Cells were cultured in fresh serum-free medium and stimulated with or without thrombin (2.5 IU/mL) for 24h. Levels of hCG in conditioned supernatant were measured by specific ELISA and corrected for protein content. Data were analyzed by ANOVA and Chi square tests. RESULTS: Thrombin significantly suppressed hCG levels in conditioned supernatant of cultured syncytiotrophoblast from 40.8 ⫾ 7.5 to 20.7 ⫾ 3.7 mIU/mg of protein per 24h (mean ⫾ SEM; n⫽6; p⫽0.038) (Figure).
403
EFFECTS OF NO-CGMP ACTIVATION ON THE FETO-PLACENTAL CIRCULATION AFTER THROMBOXANE A2-INDUCED VASOCONSTRICTION MARIE HELENE FLINE1, CELINE BROCHOT1, ESTELLE AUBRY1, VERONIQUE HOUFFLIN-DEBARGE1, LAURENT STORME1, PHILIPPE DERUELLE1, 1JE 24 90 Universite de Lille 2, Lille, France OBJECTIVE: Nitric oxide (NO) plays a major role in the regulation of fetoplacental circulation. Increased placental circulatory resistance is associated with intra uterine growth retardation (IUGR). Several in vitro studies suggest that deficiency in NO synthesis and increase in thromboxane A2 production may contribute to IUGR. However, little is known about the in vivo effects of NO-cGMP pathway on feto-placental circulation under pathological condition. We therefore hypothesize that NO-cGMP pathway modulates the regulation of constricted placental circulation. To test this hypothesis, we studied the hemodynamic response to NOcGMP activators after constriction with the thromboxane sympathomimetic U46619 in chronically-prepared, late-gestation fetal lambs (135 d; term⫽147 d). STUDY DESIGN: Catheters were inserted in the femoral vein and artery. An ultrasonic flow transducer was placed around the primitive umbilical artery to measure fetoplacental blood flow. Umbilical vascular resistances (UVR) were calculated. To induce placental constriction, U46619 was infused in the femoral artery (150g over 1h). To test the NO-cGMP signalling, 1) acetylcholine, an activator of endothelial NOS (20g over 10min); 2) 8Br-cGMP, an analogue of cGMP (3mg over 10min); and 3) sildenafil, a selective inhibitor of phosphodiesterase 5 (12mg over 2 hrs), were infused after U46619 constriction. RESULTS: U46619 infusion increased UVR from 0.093⫾0.015 to 0.110⫾0.024 mmHg/ml/min (p⬍0.01). Acetylcholine induced a slightly decrease in UVR after U46619 infusion (from 0.149⫾0.07 to 0.126⫾0.04mmHg/ml/min; NS). Sildenafil and 8Br-cGMP reduced U46619-induced vasoconstriction (from 0.128⫾0.024 to 0.103⫾0.019 mmHg/ml/min; p⬍0.01 for sildenafil and from 0.111⫾0.038 to 0.0853⫾0.009mmHg/ml/min; p⬍0.01 for 8Br-cGMP). CONCLUSION: We found that NO and thromboxane A2 play a major role in the regulation of the feto-placental circulation. NO-cGMP activators may reverse U46619-induced vasoconstriction. We speculate that sildenafil may have therapeutic potential for pathology with impaired NO production, such as IUGR. 0002-9378/$ - see front matter doi:10.1016/j.ajog.2007.10.421
CONCLUSION: Thrombin suppresses hCG production by human syncytiotrophoblast in vitro. These data suggests that bleeding in the first trimester may be a cause and not a consequence of early pregnancy loss, and may have important implications for pregnancies complicated by inherited thrombophilias. 0002-9378/$ - see front matter doi:10.1016/j.ajog.2007.10.419
402
THE EFFECT OF POSTNATAL AGE ON FETAL VASCULAR PROGRAMMING OF BLOOD PRESSURE IN A NITRIC OXIDE SYNTHASE KNOCKOUT MOUSE MODEL MONICA LONGO1, FANGXIAN LU1, ESTHER TAMAYO1, PHYLLIS GAMBLE1, ELENA SBRANA1, NIMA GOHARKHAY1, GARLAND D. ANDERSON1, GARY D.V. HANKINS1, GEORGE R. SAADE1, 1The University of Texas Medical Branch, Obstetrics and Gynecology, Galveston, Texas OBJECTIVE: To determine the effect of postnatal age on fetal vascular programming of adult blood pressure (BP) using a well characterized mouse model with abnormal uterine environment induced by lack of a functional endothelial nitric oxide synthase (NOS3), an important regulator of utero-placental perfusion. STUDY DESIGN: Homozygous NOS3 knockout (⫺/⫺KO) and wild type controls (⫹/⫹WT) were cross-bred to obtain heterozygous offspring (KOM) developing in KO mothers lacking a functional NOS3 versus genomically similar offspring (KOP) born to wild-type mothers having NOS3 gene. Male KOM and KOP offspring at 7 and 21 weeks of age were used for in vivo BP measurement by a telemetry system. A BP catheter was inserted into the aortic arch and BP monitored continuously for 8 days in the conscious unrestrained heterozygous offspring mice. The mean arterial pressure (MAP), systolic (SBP), diastolic (DBP), pulse pressure (PP) and heart rate (HR) were obtained. Their mean values over an 8 day period were calculated and Student t-test used for statistical analysis (significance: p ⬍ 0.05). RESULTS: BP in the KOM and KOP mice offspring at 7 weeks of age did not differ in any of the parameter considered. However, at 21 weeks the KOM offspring show a significant higher MAP (117.18 ⫾ 1.6 vs 109.2 ⫾ 0.9 mmHg), DBP (87.6 ⫾ 2.3 vs 57.2 ⫾ 5.6 mmHg) as well as PP and HR compared with the KOP offspring. Only SBP was not different between the two groups at 21 weeks. CONCLUSION: Heterozygous offspring born to a mother with an adverse uterine environment due to lack of NOS3 have altered BP compared with their genomically similar counterparts developing in a normal mother. The effect of fetal programming on blood pressure is not evident in early postnatal life. Early screening and intervention may present an opportunity to prevent onset of cardiovascular disease later in life.
404
TRANSPLACENTAL TRANSFER AND DISTRIBUTION OF BUPROPION ANGELA EARHART1, TATIANA NANOVSKAYA1, SVETLANA PATRIKEEVA1, ROBIN BOWEN1, GARY D.V. HANKINS1, MAHMOUD AHMED1, 1University of Texas Medical Branch, Obstetrics and Gynecology, Galveston, Texas OBJECTIVE: Bupropion is used for treatment of depression and smoking cessation in non-pregnant adults. Limited clinical trials have investigated pregnancy outcomes of women treated with bupropion for depression. The success of bupropion for smoking cessation warrants its investigation for treatment of pregnant patients. Therefore, the aim of this investigation is to determine placental transfer and distribution of bupropion, in presence and absence of human serum albumin (HSA), between the tissue, maternal and fetal circuits of the dually perfused placental lobule. STUDY DESIGN: Placentas were obtained from healthy term pregnancies. Bupropion was perfused (150ng/mL) which is its mean plasma level following a 150mg dose. The marker compound antipyrine (AP, 20 g/mL) was coperfused with bupropion to account for inter-placental variations. The [3H]-isotope of bupropion and 14C-AP were cotransfused to enhance their detection limits. The effect of HSA (30mg/mL) on transfer and distribution of bupropion was determined. The concentration of the drugs in the tissue, maternal and fetal circuits was determined by liquid scintillation spectrometry. RESULTS: Transfer of bupropion from maternal to fetal circuit was biphasic, fast in the initial 20 minutes then slower during the remaining 220 minutes of perfusion. At the end of the 4-hour period, the ratio of bupropion concentration (fetal:maternal) was 0.57⫹0.11. The distribution of bupropion was as follows: 45% of its initial concentration was retained by placental tissue, 35% remained in maternal, and 20% transferred to the fetal circuit. The addition of HSA to the perfusion medium did not affect the transfer or distribution of bupropion. CONCLUSION: Bupropion is transferred from the maternal to fetal circuits, is not affected by albumin, and appears to have no adverse effects on placental tissue viability and functional parameters. These data suggest that bupropion use during pregnancy should be further investigated to determine its safety and efficacy for smoking cessation. 0002-9378/$ - see front matter doi:10.1016/j.ajog.2007.10.422
0002-9378/$ - see front matter doi:10.1016/j.ajog.2007.10.420
Supplement to DECEMBER 2007 American Journal of Obstetrics & Gynecology
S121
www.AJOG.org 401
THROMBIN SUPPRESSES HCG PRODUCTION BY HUMAN SYNCYTIOTROPHOBLAST: A MECHANISM BY WHICH FIRST TRIMESTER BLEEDING CAUSES ABORTION VICTORIA SNEGOVSKIKH1, ERIC HODGSON1, ANNA SFAKIANAKI1, EDMUND FUNAI1, YUEHONG MA1, SETH GULLER1, MIZANUR RAHMAN1, CATALIN BUHIMSCHI1, IRINA BUHIMSCHI1, ERROL NORWITZ1, 1Yale University, New Haven, Connecticut OBJECTIVE: Bleeding in the first trimester is associated with spontaneous pregnancy loss, but whether this bleeding causes the abortion or is simply a sign of an already unsuccessful implantation is not clear. Adequate production of hCG by syncytiotrophoblast is critical to the maintenance of early pregnancy by sustaining progesterone production by the corpus luteum. We propose that bleeding may cause abortion by interfering with hCG-progesterone signalling. This study investigates the effect of thrombin on hCG production by syncytiotrophoblast in vitro. STUDY DESIGN: Term placentae were collected from elective cesarean deliveries and cytotrophoblast cells isolated by enzymatic digestion and purified using Percoll gradient. As previously described, cells were cultured in Basal Dulbecco’s medium containing 5% fetal calf serum for 3-4 days at which time syncytiotrophoblast formation was evident. Cells were cultured in fresh serum-free medium and stimulated with or without thrombin (2.5 IU/mL) for 24h. Levels of hCG in conditioned supernatant were measured by specific ELISA and corrected for protein content. Data were analyzed by ANOVA and Chi square tests. RESULTS: Thrombin significantly suppressed hCG levels in conditioned supernatant of cultured syncytiotrophoblast from 40.8 ⫾ 7.5 to 20.7 ⫾ 3.7 mIU/mg of protein per 24h (mean ⫾ SEM; n⫽6; p⫽0.038) (Figure).
403
EFFECTS OF NO-CGMP ACTIVATION ON THE FETO-PLACENTAL CIRCULATION AFTER THROMBOXANE A2-INDUCED VASOCONSTRICTION MARIE HELENE FLINE1, CELINE BROCHOT1, ESTELLE AUBRY1, VERONIQUE HOUFFLIN-DEBARGE1, LAURENT STORME1, PHILIPPE DERUELLE1, 1JE 24 90 Universite de Lille 2, Lille, France OBJECTIVE: Nitric oxide (NO) plays a major role in the regulation of fetoplacental circulation. Increased placental circulatory resistance is associated with intra uterine growth retardation (IUGR). Several in vitro studies suggest that deficiency in NO synthesis and increase in thromboxane A2 production may contribute to IUGR. However, little is known about the in vivo effects of NO-cGMP pathway on feto-placental circulation under pathological condition. We therefore hypothesize that NO-cGMP pathway modulates the regulation of constricted placental circulation. To test this hypothesis, we studied the hemodynamic response to NOcGMP activators after constriction with the thromboxane sympathomimetic U46619 in chronically-prepared, late-gestation fetal lambs (135 d; term⫽147 d). STUDY DESIGN: Catheters were inserted in the femoral vein and artery. An ultrasonic flow transducer was placed around the primitive umbilical artery to measure fetoplacental blood flow. Umbilical vascular resistances (UVR) were calculated. To induce placental constriction, U46619 was infused in the femoral artery (150g over 1h). To test the NO-cGMP signalling, 1) acetylcholine, an activator of endothelial NOS (20g over 10min); 2) 8Br-cGMP, an analogue of cGMP (3mg over 10min); and 3) sildenafil, a selective inhibitor of phosphodiesterase 5 (12mg over 2 hrs), were infused after U46619 constriction. RESULTS: U46619 infusion increased UVR from 0.093⫾0.015 to 0.110⫾0.024 mmHg/ml/min (p⬍0.01). Acetylcholine induced a slightly decrease in UVR after U46619 infusion (from 0.149⫾0.07 to 0.126⫾0.04mmHg/ml/min; NS). Sildenafil and 8Br-cGMP reduced U46619-induced vasoconstriction (from 0.128⫾0.024 to 0.103⫾0.019 mmHg/ml/min; p⬍0.01 for sildenafil and from 0.111⫾0.038 to 0.0853⫾0.009mmHg/ml/min; p⬍0.01 for 8Br-cGMP). CONCLUSION: We found that NO and thromboxane A2 play a major role in the regulation of the feto-placental circulation. NO-cGMP activators may reverse U46619-induced vasoconstriction. We speculate that sildenafil may have therapeutic potential for pathology with impaired NO production, such as IUGR. 0002-9378/$ - see front matter doi:10.1016/j.ajog.2007.10.421
CONCLUSION: Thrombin suppresses hCG production by human syncytiotrophoblast in vitro. These data suggests that bleeding in the first trimester may be a cause and not a consequence of early pregnancy loss, and may have important implications for pregnancies complicated by inherited thrombophilias. 0002-9378/$ - see front matter doi:10.1016/j.ajog.2007.10.419
402
THE EFFECT OF POSTNATAL AGE ON FETAL VASCULAR PROGRAMMING OF BLOOD PRESSURE IN A NITRIC OXIDE SYNTHASE KNOCKOUT MOUSE MODEL MONICA LONGO1, FANGXIAN LU1, ESTHER TAMAYO1, PHYLLIS GAMBLE1, ELENA SBRANA1, NIMA GOHARKHAY1, GARLAND D. ANDERSON1, GARY D.V. HANKINS1, GEORGE R. SAADE1, 1The University of Texas Medical Branch, Obstetrics and Gynecology, Galveston, Texas OBJECTIVE: To determine the effect of postnatal age on fetal vascular programming of adult blood pressure (BP) using a well characterized mouse model with abnormal uterine environment induced by lack of a functional endothelial nitric oxide synthase (NOS3), an important regulator of utero-placental perfusion. STUDY DESIGN: Homozygous NOS3 knockout (⫺/⫺KO) and wild type controls (⫹/⫹WT) were cross-bred to obtain heterozygous offspring (KOM) developing in KO mothers lacking a functional NOS3 versus genomically similar offspring (KOP) born to wild-type mothers having NOS3 gene. Male KOM and KOP offspring at 7 and 21 weeks of age were used for in vivo BP measurement by a telemetry system. A BP catheter was inserted into the aortic arch and BP monitored continuously for 8 days in the conscious unrestrained heterozygous offspring mice. The mean arterial pressure (MAP), systolic (SBP), diastolic (DBP), pulse pressure (PP) and heart rate (HR) were obtained. Their mean values over an 8 day period were calculated and Student t-test used for statistical analysis (significance: p ⬍ 0.05). RESULTS: BP in the KOM and KOP mice offspring at 7 weeks of age did not differ in any of the parameter considered. However, at 21 weeks the KOM offspring show a significant higher MAP (117.18 ⫾ 1.6 vs 109.2 ⫾ 0.9 mmHg), DBP (87.6 ⫾ 2.3 vs 57.2 ⫾ 5.6 mmHg) as well as PP and HR compared with the KOP offspring. Only SBP was not different between the two groups at 21 weeks. CONCLUSION: Heterozygous offspring born to a mother with an adverse uterine environment due to lack of NOS3 have altered BP compared with their genomically similar counterparts developing in a normal mother. The effect of fetal programming on blood pressure is not evident in early postnatal life. Early screening and intervention may present an opportunity to prevent onset of cardiovascular disease later in life.
404
TRANSPLACENTAL TRANSFER AND DISTRIBUTION OF BUPROPION ANGELA EARHART1, TATIANA NANOVSKAYA1, SVETLANA PATRIKEEVA1, ROBIN BOWEN1, GARY D.V. HANKINS1, MAHMOUD AHMED1, 1University of Texas Medical Branch, Obstetrics and Gynecology, Galveston, Texas OBJECTIVE: Bupropion is used for treatment of depression and smoking cessation in non-pregnant adults. Limited clinical trials have investigated pregnancy outcomes of women treated with bupropion for depression. The success of bupropion for smoking cessation warrants its investigation for treatment of pregnant patients. Therefore, the aim of this investigation is to determine placental transfer and distribution of bupropion, in presence and absence of human serum albumin (HSA), between the tissue, maternal and fetal circuits of the dually perfused placental lobule. STUDY DESIGN: Placentas were obtained from healthy term pregnancies. Bupropion was perfused (150ng/mL) which is its mean plasma level following a 150mg dose. The marker compound antipyrine (AP, 20 g/mL) was coperfused with bupropion to account for inter-placental variations. The [3H]-isotope of bupropion and 14C-AP were cotransfused to enhance their detection limits. The effect of HSA (30mg/mL) on transfer and distribution of bupropion was determined. The concentration of the drugs in the tissue, maternal and fetal circuits was determined by liquid scintillation spectrometry. RESULTS: Transfer of bupropion from maternal to fetal circuit was biphasic, fast in the initial 20 minutes then slower during the remaining 220 minutes of perfusion. At the end of the 4-hour period, the ratio of bupropion concentration (fetal:maternal) was 0.57⫹0.11. The distribution of bupropion was as follows: 45% of its initial concentration was retained by placental tissue, 35% remained in maternal, and 20% transferred to the fetal circuit. The addition of HSA to the perfusion medium did not affect the transfer or distribution of bupropion. CONCLUSION: Bupropion is transferred from the maternal to fetal circuits, is not affected by albumin, and appears to have no adverse effects on placental tissue viability and functional parameters. These data suggest that bupropion use during pregnancy should be further investigated to determine its safety and efficacy for smoking cessation. 0002-9378/$ - see front matter doi:10.1016/j.ajog.2007.10.422
0002-9378/$ - see front matter doi:10.1016/j.ajog.2007.10.420
Supplement to DECEMBER 2007 American Journal of Obstetrics & Gynecology
S121