Effects of castration on the expression of the NGF and TrkA in the vas deferens and accessory male genital glands of the rat

Abstract

Nerve Growth Factor (NGF) is a member of the neurotrophin family. Neurotrophins exert their effects by binding to corresponding receptors, which are formed by the tyrosine protein kinases TrkA, TrkB, and TrkC, and the low affinity p75NTR receptor. The role of neurotrophins in the biology of male genital organs is far from clear. In particular, little is known about the influence of sex hormones on the expression of neurotrophins and their receptors. In the present study, using immunohistochemistry and real time RT-PCR, we investigated the expression of NGF and TrkA in the vas deferens and accessory male genital glands in normal and castrated rats. In normal rats, both NGF-and TrkA-immunoreactivities (IR) were localized in the epithelial layer of the vas deferens. NGF-IR was also found in the stroma and epithelium of the vesicular gland and prostate. TrkA-IR was distributed in the epithelial cells of vesicular and prostate glands. The nerves were weakly immunoreactive in all the examined organs. After castration the immunoreactivities increased. Real-time RT-PCR experiments indicated that NGF and TrkA mRNA levels increased significantly after castration. These results suggest that NGF and TrkA are expressed in the internal male genital organs of the rat and that their expression is downregulated by androgen hormones. We hypothesize NGF and TrkA play a role in the processes that regulate the involution of these organs under conditions of androgen deprivation.

Expression of β‐NGF and high‐affinity NGF receptor (TrKA) in llama (Lama glama) male reproductive tract and spermatozoa

“…To the best of our knowledge, this is the first report that describes the differential expression of mRNA and proteins of β-NGF and its β-NGF, as a component of the SP, has an important role in camelids reproduction, being responsible for inducing ovulation . In other species, both prostate and vesicular glands are the major sites of β-NGF expression (Hofmann & Unsicker, 1982;Maranesi et al, 2015;Squillacioti et al, 2009). It is known that in camelids vesicular glands are absent (Tibary & Anouassi, 1997).…”

“…In this regard, expressions of β-NGF and its high-and lowaffinity receptors, TrKA and p75NTR, have been detected in different organs of the male reproductive tract in a large variety of species (Li et al, 2005;MacGrogan, Desprès, Romand, & Dicou, 1991;Shikata et al, 1984;Wang, Dong, Chen, Hei, & Dong, 2011). The prostate and seminal vesicles are the major sites of β-NGF expression in the bull (Harper & Thoenen, 1980;Hofmann & Unsicker, 1982), the male guinea pig (Harper et al, 1979), the rat (Squillacioti, De Luca, Paino, Langella, & Mirabella, 2009), and the rabbit (Maranesi et al, 2015). Both β-NGF and its corresponding receptors (TrKA and p75NTR) have been implicated in autocrine and paracrine regulation of spermatogenesis (Mutter, Middendorff, & Davidoff, 1999;Parvinen et al, 1992;Persson et al, 1990;Seidl, Buchberger, & Erck, 1996) and also in testis morphogenesis (Russo et al, 1999).…”

Localization of orexin B and receptor 2 for orexins in testicular cytotypes of the camelid alpaca (Vicugna pacos)

“…Tissue collection was performed as described by Liguori et al (2013). After removal, the testes were finely cut in small samples which were either fixed in Bouin's fluid for immunohistochemistry as described in details elsewhere (Squillacioti, De Luca, Paino, Langella, & Mirabella, 2009) or frozen in liquid nitrogen and stored at −80°C until used for Western blotting analysis.…”

Innervation and Immunohistochemical Characteristics of Epididymis in Alpaca Camelid (Vicugna Pacos)

“…The autonomic innervation plays a key role in regulation of male genital functions. Anatomical, pharmacological and physiological data (Hib, 1976;Laitinen and Talo, 1981;Pholpramool and Triphon, 1984;Mirabella et al, 2006Mirabella et al, , 2008Squillacioti et al, 2008Squillacioti et al, , 2009 suggest that the role of adrenergic and cholinergic inner- (Farrel and Lyman, 1937;Sjostrand, 1965;Mirabella et al, 2007) and blood flow (Baumgarten and Holstein, 1968;Kuwahara and Frick, 1974;Damber et al, 1982;Billups et al, 1990;Santamaria et al, 1995). Epithelial exo/endocytic events and ionic exchange between cellular and luminal compartments are other processes that are influenced by autonomic innervations (Mayerhofer et al, 1992;Chan et al, 1994;Kempinas et al, 1995;Lamano-Carvalho et al, 1996;Zhu et al, 1998).…”