OBJECTIVE: The objective of the study was to determine the effect of gestational age and P-glycoprotein expression on transplacental transfer of methadone. STUDY DESIGN: Dual perfusion of placental lobule was utilized. Methadone (200 ng/mL) and its [3H]-isotope were cotransfused from the maternal-to-fetal circuit with the marker compound antipyrine (20 microg/mL) and its [14C]-isotope. Concentration of the drugs in trophoblast tissue and both circuits was determined by liquid scintillation spectrometry. RESULTS: Fetal transfer rate of methadone in preterm placentas was 19 +/- 5.8%, and in term placentas it was 31 +/- 9.7% (P < .01). Clearance index of methadone in preterm placentas (0.57 +/- 0.2) was lower than in term placentas (0.95 +/- 0.3, P < .01). P-glycoprotein expression was higher in preterm than term placentas. CONCLUSION: The ex vivo transfer of methadone across preterm placentas is 30% lower than in term placentas.
OBJECTIVE: The objective of the study was to determine the effect of gestational age and P-glycoprotein expression on transplacental transfer of methadone. STUDY DESIGN: Dual perfusion of placental lobule was utilized. Methadone (200 ng/mL) and its [3H]-isotope were cotransfused from the maternal-to-fetal circuit with the marker compound antipyrine (20 microg/mL) and its [14C]-isotope. Concentration of the drugs in trophoblast tissue and both circuits was determined by liquid scintillation spectrometry. RESULTS: Fetal transfer rate of methadone in preterm placentas was 19 +/- 5.8%, and in term placentas it was 31 +/- 9.7% (P < .01). Clearance index of methadone in preterm placentas (0.57 +/- 0.2) was lower than in term placentas (0.95 +/- 0.3, P < .01). P-glycoprotein expression was higher in preterm than term placentas. CONCLUSION: The ex vivo transfer of methadone across preterm placentas is 30% lower than in term placentas.
Authors: Sarah J Hemauer; Tatiana N Nanovskaya; Sherif Z Abdel-Rahman; Svetlana L Patrikeeva; Gary D V Hankins; Mahmoud S Ahmed Journal: Biochem Pharmacol Date: 2009-11-06 Impact factor: 5.858
Authors: Amy L Salisbury; Mara G Coyle; Kevin E O'Grady; Sarah H Heil; Peter R Martin; Susan M Stine; Karol Kaltenbach; Manfred Weninger; Hendrée E Jones Journal: Addiction Date: 2012-11 Impact factor: 6.526