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

A. Kozłowska,B. Jana,M. Majewski

doi:10.1007/s12031-014-0239-1

Abstract

We revealed earlier that induction of ovarian cysts in gilts by dexamethasone phosphate disodium salt (DXM) administration from the follicular phase of the estrous cycle (EC) changed the cholinergic innervation of the gonad. In the present study, the innervation of porcine ovaries by vesicular acetylcholine transporter (VAChT)-, neuronal nitric oxide synthase (nNOS)-, vasoactive intestinal peptide (VIP)- and somatostatin (SOM)-immunoreactive (IR) fibres, after induction of cystic changes from the middle luteal phase of the EC, was determined. The cystic changes were induced by DXM injections from days 7 to 21 of the EC, and 11 days later, the ovaries were collected. In the cystic ovaries, VAChT-, nNOS- and SOM-IR fibres were found around cysts and small tertiary follicles; nNOS-IR and also VAChT-IR fibres were observed near secondary follicles and veins; and VAChT- and nNOS-IR fibres were not found around cortical arteries. The number of VIP-IR fibres increased near the cysts and within the ground plexus, while the number of VAChT-IR fibres decreased within the medullar part of this structure. Thus, our study showed changes in the cholinergic innervation pattern of the porcine cystic ovaries induced from the middle phase of the cycle and confirmed that cystic ovary innervation depends partly on the phase of the EC in which the induction of cysts was started.

Highlights

The porcine ovary receives its nerve supply from sympathetic, parasympathetic and sensory components of the peripheral nervous system (PNS)
In the ovaries of DXM-treated gilts, in contrast to the CON group (Figs. 1a—vesicular acetylcholine transporter (VAChT), 1b—neuronal nitric oxide synthase (nNOS), 3a—VAChT, 3b—nNOS and 25—SOM), VAChT- and nNOS-IR fibres were found near the secondary (Fig. 2a, b; respectively) and tertiary follicles measuring up to 3 mm (Fig. 4a, b; respectively), while SOM-IR fibres were visible within the ground plexus (Fig. 26) and around the tertiary follicles measuring up to 3 mm
No immunostaining for VAChT (Fig. 7a), nNOS (Fig. 7b), vasoactive intestinal peptide (VIP) (Fig. 22) and SOM (Fig. 29) was detected in the control ovaries when the primary antibodies were substituted with normal IgGs

Summary

Introduction

The porcine ovary receives its nerve supply from sympathetic, parasympathetic and sensory components of the peripheral nervous system (PNS). Many possibilities are involved in COD development and maintenance. This disease results mainly from a dysfunction of the hypothalamic-pituitary-ovarian axis function (see review of Ahmed et al 2003). It was revealed that in rats, the steroid-induced augmentation in the sympathetic nerve activity and stress are able to cause a cystic condition similar to polycystic ovary syndrome (PCOS) in humans (Dorfman et al 2003). The importance of the sympathetic nerve activity to the development and/or maintenance of ovarian cysts was indicated in cows (Paredes et al 2011). In the studies performed on gilts, we have found that in the dexamethasone

Methods

Results

Conclusion