Transport kinetics of alpha-aminoisobutyric acid and water in pre-eclamptic pregnancies: an in vitro study.
OBJECTIVE
To investigate the transport kinetics of a model amino acid, alpha-aminoisobutyric acid (AIB), in the maternal-fetal direction in placentae from pre-eclamptic pregnancies.


METHODS
Transport kinetics of the amino acid was assessed in vitro using perfusion of human placental lobules. Control placental lobules were perfused for comparison. National Culture and Tissue Collection--135 medium diluted with Earle's buffered salt solution was used as the perfusate, and tritiated water served as the internal reference marker. AIB along with reference marker was injected as a single bolus into the maternal arterial perfusate, and serial perfusate samples were collected from maternal and fetal venous circuits for a study period of 5 min.


RESULTS
The differential transport rate of the amino acid for various efflux fractions differed significantly between control and experimental groups when compared to that of the reference marker. The transport rate (corresponding to 50% of efflux into the fetal vein), transport fraction, absorption and elimination rates of the amino acid differed significantly compared to the reference marker values in study and control groups.


CONCLUSIONS
The results indicate that amino acid transport function is compromised in placentae of pre-eclamptic pregnancies.
Nandakumaran
Moorkath
M
Obstetrics and Gynecology Department, Faculty of Medicine, Kuwait University, PO Box 24923, Safat 13110, Kuwait. moorkath@hsc.kuniv.edu.kw
Omu
Alexander
A
Diejomaoh
Michael
M
al-Yatama
Majda
M
Harouny
Assem K
AK
Sugathan
Thattaruparambil N
TN
D000328:Adult; D000621:Aminoisobutyric Acids / Q000493:pharmacokinetics*; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D008431:Maternal-Fetal Exchange; D010920:Placenta / Q000378:metabolism*; D011225:Pre-Eclampsia / Q000503:physiopathology*; D011247:Pregnancy; D014867:Water / Q000378:metabolism*
D000621:Aminoisobutyric Acids; D014867:Water; C100049:2-aminoisobutyric acid