Reduction of the Number of Neurones in the Caudal Mesenteric Ganglion Innervating the Ovary in Sexually Mature Gilts Following Testosterone Administration

Abstract

The effect of testosterone on the morphological and chemical plasticity of the porcine caudal mesenteric ganglion (CaMG) ovary‐projecting neurones was investigated. To identify the neurones on day 3 of the oestrous cycle, the ovaries of both the control and experimental gilts were injected with Fast Blue retrograde neuronal tracer. From next day until day 20 of the anticipated second studied cycle, experimental gilts were injected with testosterone, whereas control gilts received oil. Testosterone injections increased testosterone (by approximately 3.5‐fold) and 17β‐oestradiol (by approximately 1.6‐fold) levels in the peripheral blood and decreased the following in the CaMG: the total number of Fast Blue‐positive perikarya (including small ones); the population of small perikarya in the caudal, ventral and dorsal ganglional regions; the numbers of dopamine‐β‐hydroxylase (DβH) and/or neuropeptide Y (NPY), somatostatin (SOM), galanin (GAL) small and large perikarya; the numbers of small perikarya containing DβH (but not NPY, SOM, GAL); and the density of DβH and/or NPY, SOM nerve fibres. A disappearance of small and large non‐noradrenergic perikarya and an increase in the total number of androgen receptor‐immunoreactive perikarya was noted. Our results suggest that elevated androgen levels occurring during pathological states may regulate ovary function(s) by affecting the CaMG gonad‐supplying neurones.

Changes in the Cholinergic Innervation Pattern of Porcine Ovaries with Cysts Induced by Dexamethasone Administration

“…It is recognized that estrogen receptors are expressed in the ovarian neurons of sympathetic and parasympathetic as well as sensory ganglia in adult gilts and that the long-term 17β-estradiol treatment reduced the population of these neurons (Koszykowska et al 2011a, b; Jana et al 2012, 2013a). A similar situation has been revealed for neurons in the caudal mesenteric ganglion innervating the ovary in adult gilts following testosterone administration (Jana et al 2013b). It is worth noting that in the gilts, from which the cystic ovaries were collected for the present study, the peripheral blood levels of sex steroids were markedly changed (Jana, unpublished data).…”

Long-term treatment with testosterone alters ovary innervation in adult pigs

“…The plasma was decanted and stored at −20 °C until further processing. The analysis of androgen and oestrogen concentrations in the peripheral blood of the gilts was described earlier [ 40 ]. After the last blood sample collection the gilts were slaughtered by electric shock (ENZ 300 Metalowiec, Bydgoszcz, Poland) and both ovaries from each gilt were immediately dissected out and weighed.…”

“…In fact, the pig, due to its embryological, anatomical and physiological similarity to humans, constitutes an especially valuable species for bio-medical research, including that of ovary functions [ 38 , 39 ]. Our earlier studies revealed that long-term testosterone (T) treatment alters the morphological and chemical organization of the CaMG [ 40 ], PCG [ 41 ] and SChGs [ 42 ] ovarian perikarya in adult gilts. Taking into consideration the above-mentioned findings, we hypothesize that elevated levels of androgens during pathological states may also affect the innervation pattern, including sympathetic ones, in the ovaries, and finally the gonadal functions.…”

The regulative effect of galanin family members on link of energy metabolism and reproduction

“…A study reported that an injection of testosterone decreased the number of galanin cells in small and large perikarya of the porcine caudal mesenteric ganglion [72]. Other …”