Fig. 13.

Insulin signaling up-regulates 5-HT uptake rates of trophoblast of normal placentas. Insulin treatment on ERp44-SERT dissociation was followed by determining the 5-HT uptake rates of trophoblast following a pretreatment with either 100 nM insulin or 5 μM AGL2263 or with both insulin (100 nM) and AGL2263 (5 μM). Trophoblast cells were isolated and purified from normal and GDM placentas (all groups, n = 5). Then the [³H]-5HT uptake rates were measured in intact cells (2.3 × 10⁵ per assay). Rate of uptake is expressed as the means and SD values of triplicate determinations from three independent samples in each group. The values are statistically different (P < 0.001, Student t test). Asterisks indicate statistical difference between normal and GDM trophoblast (*); insulin pretreated and untreated normal trophoblast (**).