Prenatal exposure to diethylstilbestrol decreases the number of estrogen receptor alpha-containing neurons innervating the ovary in rat celiac ganglion.

Recently, we reported that, in rats, transplacental exposure to diethylstilbestrol, a potent synthetic estrogen, decreases the density of the ovarian sympathetic nerve network compared to that in control rats not exposed to diethylstilbestrol. To clarify the mechanism of the decrease in the density, we performed a series of experiments using rats prenatally exposed to diethylstilbestrol and unexposed control rats. First, a retrograde tract tracer, Fast Blue, was microinjected into the ovaries of both groups of rats at four months of age, and the number of Fast Blue-positive neurons in the celiac ganglion was counted. The number of neurons in the ganglion was smaller in diethylstilbestrol-exposed rats than in the controls. Second, double labeling of the neurons with antibody against estrogen receptor alpha and Fast Blue in the celiac ganglion was carried out in both groups of rats. The results showed that estrogen receptor alpha-containing neurons in the ganglion innervated the ovary, and their number was decreased selectively by prenatal diethylstilbestrol exposure. Finally, a decrease in the celiac ganglion volume in rats prenatally exposed to diethylstilbestrol was also detected on day 23 of gestation, as compared to the volume in the control rats. From these observations, we propose that prenatal exposure to diethylstilbestrol can induce a loss of estrogen receptor alpha-containing neurons innervating the ovary during development, resulting in paucity of the neural network in the ovary.