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

Abstract

BackgroundIntraovarian distribution and density of nerve fibres immunoreactive (IR) to protein gene product 9.5 (PGP 9.5) and containing dopamine-β-hydroxylase (DβH), neuropeptide Y (NPY), somatostatin (SOM), galanin (GAL) were determined.MethodsFrom day 4 of the first oestrous cycle to day 20 of the second studied cycle, experimental gilts (n = 3) were injected with testosterone (T), while control gilts (n = 3) received corn oil.ResultsAfter T administration the numbers of fibres IR to PGP 9.5 and fibres IR to DβH, NPY and SOM were decreased. Fewer PGP 9.5- and DβH-IR terminals were observed within the ground plexus and around arteries and medullar veins, and medium tertiary follicles, and DβH-IR terminals in the vicinity of small tertiary follicles. T decreased the density of NPY-IR fibres in the medullar part of the ground plexus, and SOM-IR in the cortical part of the ground plexus.ConclusionsThe obtained data show that long-term T treatment of gilts decreases the total number of intraovarian fibres, including sympathetic ones. These results suggest that elevated T levels that occur during pathological states may affect the innervation pattern of ovaries, and their function(s).

Neuropeptide Y directly reduced apoptosis of granulosa cells, and the expression of NPY and its receptors in PCOS subjects

“…However, there are no reports demonstrating how NPY functions at the ovarian level of PCOS in either animal models or human studies. In the present study, we observed for the first time that postnatal DHT treatment reduced NPY expression in granulosa cells, which is consistent with NPY level in ovarian nerve fiber [ 26 ] and in contrast with that in the central neuron system [ 9 , 10 ]. The tissue-specific variation of NPY expression suggests that NPY may function in both paracrine and autocrine manners.…”

“…In several PCOS animal models, chronic androgen excess induces NPY expression in arcuate nucleus of the hypothalamus and Npy mRNA abundance in adipose tissue [ 9 , 10 , 25 ]. On the other hand, Jana et al reported that postnatal treatment of testosterone in gilts reduced both NPY-immunoreactivity and total nerve fibers in ovaries [ 26 ]. In human, serum NPY level in normal weight PCOS women was higher than those in non-PCOS women [ 22 , 23 ].…”