Diabetes, Vol 39, Issue 8 914-918, Copyright © 1990 by American Diabetes Association
Alterations in transfer and lipid distribution of arachidonic acid in placentas of diabetic pregnancies
DC Kuhn, MA Crawford, MJ Stuart, JJ Botti and LM Demers
Department of Obstetrics and Gynecology, M.S. Hershey Medical Center, Pennsylvania State University, Hershey 17033.
Placental tissue from nondiabetic term pregnancies and pregnancies
complicated by maternal insulin-dependent diabetes mellitus (IDDM) was
perfused in vitro to compare the transfer and lipid distribution of
arachidonic acid (AA). Radiolabeled albumin-bound AA was administered into
the maternal afferent circulation, and samples of fetal and maternal
effluent were collected at 10-min intervals. Perfused placental tissue was
collected at the end of each experiment. The effluent was analyzed for
total radioactivity, and extracts were subjected to thin-layer
chromatography for the assessment of radioactivity associated with various
lipid fractions. Placental AA uptake was significantly increased in
perfused tissue from diabetic pregnancies (0.88 vs. 1.72 nM.min-1.g-1 in
nondiabetic and IDDM, respectively; P less than 0.01), as was AA transfer
(0.22 vs. 0.42 ml/min in nondiabetic and IDDM, respectively; P less than
0.01). However, transfer of the highly diffusible marker substance
antipyrine was significantly reduced in IDDM placentas (1.79 vs. 2.49
ml/min in IDDM and nondiabetic, respectively; P less than 0.01). Compared
with nondiabetic placentas, incorporation of AA into triglyceride was
significantly increased in both maternal and fetal effluents and in
placental tissue from IDDM pregnancies, whereas the percentage of AA
remaining unesterified was reduced in both placental tissue and fetal
effluent. Incorporation of AA into phosphoglycerides was significantly
reduced in placental tissue but increased in fetal effluent in placentas
from IDDM pregnancies. The results of these studies suggest that transfer
and lipid distribution of AA are significantly altered in placentas from
IDDM pregnancies. These findings may be relevant to the increased incidence
of abnormal fetal growth and development associated with IDDM pregnancies.