Morphological and neurochemical characterization of the ovarian sympathetic chain ganglia perikarya in testosterone-treated sexually matured pigs.

Abstract We studied the effect of testosterone overdose on the number, distribution and chemical coding of ovarian neurons in the sympathetic chain ganglia (SChGs) in pigs. On day 3 of the estrous cycle the ovaries of both the control and experimental gilts were injected with retrograde neuronal tracer Fast Blue to identify the neurons innervating gonads. From the following day to the expected day 20 of the second studied cycle the experimental pigs were injected with testosterone, while the control pigs received oil, and subsequently the SChG Th16-S2 were collected. Testosterone injections increased testosterone (∼3.5 fold) and estradiol-17β (∼1.6 fold) levels in the peripheral blood, and reduced the following in the SChGs: the total number of Fast Blue-positive neurons, the numbers of perikarya in the L3–L5 ganglia, the numbers of perikarya in the ventral, dorsal and central regions of the SChGs, and the numbers of DβH + /NPY + , DβH + /GAL + , DβH + /NPY − , DβH + /SOM − and DβH + /GAL − perikarya. In the testosterone-affected SChGs, the perikarya DβH − /SOM + , DβH − /GAL + and DβH − /NPY − were absent. In these ganglia, the population of androgen receptor-positive perikarya was increased, while the population of estrogen receptor-expressing perikarya was lowered. Our data indicate that in the pig SChGs elevated androgen levels occurring during pathological states may affect the morphology and chemical coding of ovarian neurons.