Table 3

Glycocholate placental uptake and bile secretion by maternal liver

[¹⁴C]GC Infusion through	Control	OCP	OCP + UDCA
Umbilical Artery
Placental content at min 2
nmol	5.56 ± 0.08	2.20 ± 0.09^a	3.02 ± 0.21^3-b
Placental content at min 10
nmol	1.86 ± 0.12	1.38 ± 0.14^a	1.90 ± 0.05^3-b
Percentage of uptake	33.4%	62.7%	62.9%
Cumulative bile output
nmol	5.37 ± 0.15	1.35 ± 0.14^a ^3-c	2.87 ± 0.18^3-b
Percentage of uptake	96.6%	61.4%	95.0%
t _1/2
min	20.1 ± 1.0	56.2 ± 2.8^a	32.6 ± 1.6^3-b
Maternal Jugular Vein
Cumulative bile output
nmol	4.33 ± 0.17	3.73 ± 0.15^a	4.53 ± 0.18^3-b
t _1/2
min	10.7 ± 0.5	23.8 ± 1.2^a	24.3 ± 1.3

The amount of [¹⁴C]GC retained by the placenta after administration (250 nmol over 5 min) through the umbilical artery of in situ perfused rat placentas in 21-day pregnant rats was measured after a 2- or 10-min washing period with [¹⁴C]GC-free perfusion medium. In two separate sets of animals, values of [¹⁴C]GC bile output into maternal bile over 3 h after administration of [¹⁴C]GC through the umbilical artery (250 nmol over 5 min) or through the maternal jugular artery (5 nmol over 5 min) were used to calculate AUC (area under the curve or accumulated output with no extrapolation to infinity) and MRT (mean residence time) by numerical integration using the trapezoidal rule. The half-life time (t_1/2) of [¹⁴C]GC in the maternal compartment was calculated as Ln2/K_e, where K_e(elimination constant) was 1/MRT (Yamaoka et al., 1978). Groups were control, and rats undergoing surgical common bile duct obstruction on day 14 that, for the remaining 7 days, received the vehicle (OCP group) or 60 μg of UDCA/100 g b.wt./day (OCP + UDCA group). Values are means ± S.E.M. (n ≥ 5).

a P < 0.05, on comparing OCP to Controls;
↵3-b P < 0.05 on comparing OCP + UDCA to OCP;
↵3-c P < 0.05 on comparing placental uptake to cumulative bile output. Comparisons were carried out by the Bonferroni method of multiple range testing.