Innervation and immunohistochemical characteristics of epididymis in Alpaca camelid (Vicugna pacos)

Alpacas (Vicugna pacos) are domesticated camelids indigenous to south America and recently also bred in Europe and Italy for their high quality wool. There is little data available regarding the innervation of the male reproductive tract of this species. In the present study, the distribution of protein gene product 9.5 (PGP 9.5), neuropeptide Y (NPY), tyrosine hydroxilase (TH), calcitonin gene related peptide (CGRP) and substance P (SP) was analyzed in the epididymis by using immunohistochemical methods. Specimens of the caput, corpus and cauda epididymis were fixed in Bouin's fluid and processed for immunohistochemistry analysis with primary antibodies against PGP 9.5, NPY, TH, CGRP and SP. Immunopositivity to PGP 9.5 and TH and NPY was observed in nerve fibre bundles and in single nerve fibres contained into the peritubular connective tissue. Many TH and NPY immunopositive cells were found to innervate blood vessels. Rare CGRP and SP immunopositive nerves were observed. Several PGP 9,5 and NPY immunopositive epithelial cells were observed in the caput epididymis. The results of the present study suggest a role for the innervations in modulate reproductive functions in the alpaca epididymis

Urocortins in the mammalian endocrine system

Urocortins (Ucns), peptides belonging to the corticotropin-releasing hormone (CRH) family, are classified into Ucn1, Ucn2, and Ucn3. They are involved in regulating several body functions by binding to two G protein-coupled recep- tors: receptor type 1 (CRHR1) and type 2 (CRHR2). In this review, we provide a historical overview of research on Ucns and their receptors in the mammalian endocrine system. Although the literature on the topic is limited, we focused our attention particularly on the main role of Ucns and their receptors in regulating the hypothalamic–pituitary–adre- nal and thyroid axes, reproductive organs, pancreas, gastrointestinal tract, and other tissues characterized by “diffuse” endocrine cells in mammals. The prominent function of these peptides in health conditions led us to also hypothesize an action of Ucn agonists/antagonists in stress and in various diseases with its critical consequences on behavior and physiology. The potential role of the urocortinergic system is an intriguing topic that deserves further in-depth investi- gations to develop novel strategies for preventing stress-related conditions and treating endocrine diseases

Orexin A-Mediated Modulation of Reproductive Activities in Testis of Normal and Cryptorchid Dogs: Possible Model for Studying Relationships Between Energy Metabolism and Reproductive Control

Orexin A (OxA) is a neuropeptide produced in the lateral hypothalamus that performs pleiotropic functions in different tissues, including involvement in energy homeostasis and reproductive neuroendocrine functions. The role of OxA is particularly important given the well-studied relationships between physiological mechanisms controlling energy balance and reproduction. The enzyme P450 aromatase (ARO) helps convert androgens to estrogens and has roles in steroidogenesis, spermatogenesis, and energy metabolism in several organs. The goal of this study was thus to investigate the role of OxA in ARO activity and the effects of this regulation on reproductive homeostasis in male gonads from healthy and cryptorchid dogs. The cryptorchidism is a specific condition characterized by altered reproductive and metabolic activities, the latter of which emerge from impaired glycolysis. OxA helps to stimulate testosterone (T) synthesis in the dog testis. We aimed to investigate OxA-mediated modulation of 17β-estradiol (17β-E) synthesis, ARO expression and metabolic indicators in testis of normal and cryptorchid dogs. Our results indicate putative effects of OxA on estrogen biosynthesis and ARO activity based on western blotting analysis and immunohistochemistry for ARO detection and in vitro tests. OxA triggered decrease in estrogen production and ARO activity inhibition; reduced ARO activity thus prevented the conversion of T to estrogens and increasing OxA-mediated synthesis of T. Furthermore, we characterized some metabolic and oxidative modulations in normal and cryptorchid dog's testis. The steroidogenic regulation by OxA and its modulation of ARO activity led us to hypothesize that OxA is a potential therapeutic target in pathological conditions associated with steroidogenic alterations and OxA possible involvement in metabolic processes in the male gonad

Do Animals Play a Role in the Transmission of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2)? A Commentary

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) belongs to the Beta-coronavirus genus. It is 96.2% homologous to bat CoV RaTG13 and 88% homologous to two bat SARS-like coronaviruses. SARS-CoV-2 is the infectious agent responsible for the coronavirus disease (COVID-19), which was first reported in the Hubei province of Wuhan, China, at the beginning of December 2019. Human transmission from COVID-19 patients or incubation carriers occurs via coughing, sneezing, speaking, discharge from the nose, or fecal contamination. Various strains of the virus have been reported around the world, with different virulence and behavior. In addition, SARS-CoV-2 shares certain epitopes with some taxonomically related viruses, with tropism for the most common synanthropic animals. By elucidating the immunological properties of the circulating SARS-CoV-2, a partial protection due to human–animal interactions could be supposed in some situations. In addition, differential epitopes could be used for the differential diagnosis of SARS-CoV-2 infection. There have been cases of transmission from people with COVID-19 to pets such as cats and dogs. In addition, wild felines were infected. All These animals were either asymptomatic or mildly symptomatic and recovered spontaneously. Experimental studies showed cats and ferrets to be more susceptible to COVID-19. COVID-19 positive dogs and felines do not transmit the infection to humans. In contrast, minks at farms were severely infected from people with COVID-19. A SARS-Cov-2 variant in the Danish farmed mink that had been previously infected by COVID-19 positive workers, spread to mink workers causing the first case of animal-to-human infection transmission that causes a moderate decreased sensitivity to neutralizing antibodies. Thus, more investigations are necessary. It remains important to understand the risk that people with COVID-19 pose to their pets, as well as wild or farm animals so effective recommendations and risk management measures against COVID-19 can be made. A One Health unit that facilitates collaboration between public health and veterinary services is recommended

Expression of Orexin A and its Receptor 1 in the Epididymis of the South American Camelid Alpaca (Vicugna pacos).

Orexins A (ox A) and B are two peptides originally discovered in neurons of rat hypothalamus, and later found in different cellular types of the gastrointestinal and genital tracts. They arise from the proteolytic cleavage of a common precursor molecule, prepro-orexin, and bind to two receptors, namely receptor 1 (ox1r) and receptor 2 for orexins, that show different binding affinity. The central role of the two peptides has been extensively studied, whereas their activity in the periphery is still poorly known. Here, we investigated the presence of ox A and ox1r in the epididymis of a South American camelid species, the alpaca, by immunohistochemistry, and we also assessed the expression of prepro-orexin and ox1r in tissue extracts by Western blotting analysis. Ox A- and ox1r-immunoreactivity was found in the cytoplasm of principal cells of the caput epididymis. A prevalent supranuclear localization of granular-shaped positive material was observed. No positivity was present in the other cytotypes of epididymis. The expression of two peptides with molecular weight corresponding to those of prepro-orexin and ox1r, respectively, was detected in the tissue extracts from the organ

Presence and Distribution of Urocortin and its Receptors in the Epididymis of Alpaca (Vicugna pacos).

Urocortin 1 (UCN) is a 40-amino acid peptide belonging to the corticotrophin-releasing hormone (CRH) family. The biological effects of this peptide are modulated by binding two G-coupled receptors named CRH receptor 1 (CRHR1) and CRH receptor 2 (CRHR2). CRHR2 has high affinity for UCN. The aim of the present study was to investigate the presence and distribution of UCN, CRHR1 and CRHR2 in the epididymis of the South America camelid Alpaca (Vicugna pacos) by Western blotting analysis and immunohistochemistry. Tissue extracts of the organ reacted with the anti-UCN, anti-CRHR1 and anti-CRHR2 antibodies, recognizing in all the cases a single specific protein band. UCN- and CRHR2-immunoreactivities (IRs) were found in the cytoplasm of the principal cells (PCs) of the caput epididymis. A prevalent supranuclear localization of granular-shaped positive material was observed. CRHR1-IR was observed in the fibromuscular stromal cells encircling the tubules and in the smooth musculature of the blood vessels throughout the three epididymal segments. In addition, in the cauda, CRHR1-IR was observed in some apical epithelial cells (ACs) which were morphologically similar to apical mitochondria-rich cells (AMRCs). These results suggest that UCN, CRHR1 and CRHR2 are expressed in the alpaca epididymis and that CRH-related peptides might play multiple roles in maturation and storage of spermatozo

Expression of urocortin and corticotropin-releasing hormone receptors in the horse thyroid gland

Urocortin (UCN) is a 40-amino-acid peptide and a member of the corticotropin-releasing hormone (CRH) family, which includes CRH, urotensin I, sauvagine, UCN2 and UCN3. The biological actions of CRH family peptides are mediated via two types of G-protein-coupled receptors, namely CRH type 1 receptor (CRHR1) and CRH type 2 receptor (CRHR2). The biological effects of these peptides are mediated and modulated not only by CRH receptors but also via a highly conserved CRH-binding protein (CRHBP). Our aim was to investigate the expression of UCN, CRHR1, CRHR2 and CRHBP by immunohistochemistry, Western blot and reverse transcription with the polymerase chain reaction (RT-PCR) in the horse thyroid gland. The results showed that UCN, CRHR1 and CRHR2 were expressed in the thyroid gland, whereas CRHBP was not expressed. Specifically, UCN immunoreactivity (-IR) was found in the thyroid follicular cells, CRHR2-IR in the C-cells and CRHR1-IR in blood vessels. Western blot analysis and RT-PCR experiments confirmed the immunohistochemical data. These results suggest that a regulatory system exists in the mammalian thyroid gland based on UCN, CRHR1 and CRHR2 and that UCN plays a role in the regulation of thyroid physiological functions through a paracrine mechanism

Expression of urocortin and its receptors in the rat epididymis

Urocortin (UCN; 40 aa) is a corticotrophin-releasing hormone (CRH)-related peptide. The biological actions of CRH family peptides are mediated by two types of G-protein-coupled receptors, CRH type 1 receptor (CRHR1) and CRH type 2 receptor (CRHR2). The biological effects of the peptides are mediated and modulated not only by CRH receptors but also by a highly conserved CRH-binding protein (CRHBP). The aim of the present study was to investigate the expression of UCN, CRHR1, CRHR2 and CRHBP by immunohistochemistry, Western blot, RT-PCR and real-time RT-PCR in the rat epididymis. Urocortin, CRHR1 and CRHR2, but not CRHBP, were expressed in all segments of the rat epididymis. Specifically, UCN- and CRHR2-immunoreactivities (IRs) were distributed in epididymal epithelial cells of the caput, corpus and cauda. CRHR1-IR was found in the fibromuscular cells surrounding the epididymal duct and in the smooth musculature of the blood vessels throughout the organ. UCN and CRHR2 mRNA expression levels were higher in the caput and corpus than in the cauda, while CRHR1 mRNA level was higher in the cauda than those in the caput and corpus. In summary, UCN, CRHR1 and CRHR2 are expressed in the rat epididymis. It is suggested that CRH-related peptides might play multiple roles in the maturation and storage of spermatozoa