The influence of active immunisation against GnRH on adrenergic innervation of the porcine testis, epididymis and vas deferens. A quantitative and morphological study

This study investigated the influence of active immunisation against Gn-RH on adrenergic innervation of the porcine testis, epididymis and vas deferens. Seven groups of the boars were used including three control groups (n=9) Gl, G2 and G3 consisting of non-immunised animals aged 10,18 and 26 weeks, respectively, and four groups of immunised pigs (7-9 animals in each group). All the experimental boars (G4-G7) were immunised at the age of 10 weeks. Then, the animals from the two groups (G6, G7) were immunised again at age of 18 weeks. The vasa deferentia from the immunised pigs were collected at the age of 18 weeks (G4, immunised once) and at the age of 26 weeks (G5, immunised once, and two groups, G 6 and G7, immunised twice). Immunisation was accomplished by vaccination with GnRH using vaccine obtained from Peptech Animal Health, Australia. Tissue concentrations of noradrenaline (NA) were determined using high performance liquid chromatography (HPLC), and double-immunolabellings for PGP 9.5, SNAP-25 and DßH were also performed. Immunohistochemistry revealed numerous PGP- or SNAP-25-positive (+) nerve fibres supplying the organs. The vast majority of them contained also DßH. The study revealed a gradual age-dependent decrease in NA tissue concentration and a density of PGP 9.5+, SNAP-25+ and DßH+ innervation of the testis and epididymis in the control animals (G1-G3). However, in the effectively immunised animals (especially in the boars of G7 immunised twice), both NA tissue concentration and the density of the innervation were significantly higher than those found in the animals of the corresponding control groups. With regard to the vas deferens, no distinct differences in both NA tissue concentration and in a density of the innervation between the particular animal groups including those consisting of the control and immunised boars were observed. The results obtained strongly confirm previous suggestions on the existence of an inverse relationship between the nervous and hormonal systems at the level of the porcine testis.