Anatomical, Histological and Immunohistochemical Study of the Reproductive System Accessory Glands in Male Viscacha (Lagostomus maximus maximus)

Comparative analysis of male reproductive accessory glands in bats Histiotus velatus (Vespertilionidae), Molossus rufus (Molossidae), and Peropteryx leucoptera (Emballonuridae)

Despite the high number of species and wide geographic dispersion, reproductive accessory glands (RAGs) of bats have traditionally received little attention in the literature, with some species not even having a basic description of their composition and structure. Thus, this study aimed to analyze and compare the composition, anatomy, and histology of male RAGs of bat species belonging to three of the largest (cosmopolitan) bat families: Vespertilionidae (Histiotus velatus), Molossidae (Molossus rufus), and Emballonuridae (Peropteryx leucoptera), in order to understand the variations in the bat RAGs. The results showed that the RAGs of H. velatus, M. rufus, and P. leucoptera are composed of an intra-abdominal prostatic complex, associated with the urethra, urethral glands, and a pair of inguinal bulbourethral glands; without ampullary glands or seminal vesicles. The prostatic complex can be composed of two (M. rufus and P. leucoptera) or three (H. velatus) prostatic regions, and can be compact (P. leucoptera), semi-lobed (M. rufus), or multilobed (H. velatus). Each prostatic region has unique and distinct characteristics, with the ventral region presenting a holocrine nature, exclusive to bats; while the dorsal and/or dorsolateral regions have similar characteristics to the ventral prostate of rats and to the human peripheral zone.

Comparison of the structural and ultrastructural characteristics of the female prostate between pregnant and non-pregnant plains viscacha (Lagostomus maximus)

Some years ago, our group reported the presence of the female prostate in all the studied females of the plains viscacha (Lagostomus maximus). The goal of the present study was to characterize and compare the female prostate gland between adult pregnant and non-pregnant plains viscacha using histochemical, lectin-histochemical and immunohistochemical techniques, as well as optic and electron microscopy. Structurally, alveoli are lined by a simple epithelium formed by different cell types: basal cells, secretory cells in different stages of the secretory cycle and cells of clear cytoplasm. Secretory cells are the most abundant cell type, differing between them depending on the quantity and electron-density of their granules. The basal cells are less abundant and are responsible for the renewal of the alveolar epithelium. Likewise, other cells with secretory morphology were found in all the studied females; these have a clear cytoplasm, few granules and mitochondria. It could be considered that they are degranulated secretory cells or that they have partially released their granules. The stroma of the organ is formed by connective tissue and smooth muscle fibers, which are immunohistochemically evidenced against desmin. Histochemical and lectin-histochemical analysis revealed the presence of different glucidic residues in the different cell types. No structural, histochemical, lectin-histochemical, and ultrastructural differences were observed between pregnant and non-pregnant females of plain viscachas, except for the expression of some lectins. The paraurethral gland of Lagostomus maximus can be used as a model for studying the gland in other species since its structural and ultrastructural characteristics do not depend on the hormonal status of the female.

A Seasonal and Age-Related Study of Interstitial Cells in the Pineal Gland of Male Viscacha (Lagostomus maximus maximus)

The pineal gland of viscacha exhibits histophysiological variations throughout the year, with periods of maximal activity in winter and minimal activity in summer. The aim of this work is to analyze the interstitial cells (IC) in the pineal gland of male viscachas in relation to season and age. The S-100 protein, glio-fibrillary acidic protein (GFAP), and vimentin were detected in adult and immature animals by immunohistochemistry (IHC). Double-IHC was also performed. The S-100 protein was localized within both, IC nucleus and cytoplasm. GFAP was present only in the cytoplasm. Vimentin was expressed in some IC, besides endothelial cells, and perivascular spaces. In the adult males, the morphometric parameters analyzed for the S-100 protein and GFAP exhibited seasonal variations with higher values of immunopositive area percentage in winter and lower values in summer, whereas the immature ones showed the lowest values for all the adult animals studied. Colocalization of S-100 protein and GFAP was observed. The IC exhibited differential expression for the proteins studied, supporting the hypothesis of the neuroectodermal origin. The IC generate an intraglandular communication network, suggesting its participation in the glandular activity regulation processes. The results of double-IHC might indicate the presence of IC in different functional stages, probably related to the needs of the cellular microenvironment. The morphometric variations in the proteins analyzed between immature and adult viscachas probed to be more salient in the latter, suggesting a direct relationship between the expression of the S-100 protein and GFAP, and animal age. Anat Rec, 2017. © 2017 Wiley Periodicals Inc. Anat Rec, 300:1847-1857, 2017. © 2017 Wiley Periodicals, Inc.

Epididymis of Viscacha (Lagostomus maximus maximus): A Morphological Comparative Study in Relation to Sexual Maturity

The morphological variations and the androgen receptor (AR) expression were studied in viscacha epididymis in relation to sexual maturity. The animals were divided into immature, pre-pubertal and adult, according to their corporal weight and testicular histology. The epididymides were studied by light microscopy, immunohistochemistry for AR and morphometric analysis. In pre-pubertal and adult animals, four well-differentiated segments (initial, caput, corpus and cauda) were observed, while in immature animals, three segments were identified (initial-caput segment, corpus and cauda). In each segment, the structural parameters and the relative cell distribution were different between the groups. The serum testosterone levels of pre-pubertal and adults showed a very significant increase related to sexual maturity. The AR expression in epithelial and fibromuscular stromal cells was different between the groups. In conclusion, the present work demonstrates that the morphological characteristics of the viscacha epididymis vary while sexual maturity is reached, the development of initial and caput is subsequent to corpus and cauda development and the androgens might play an important role during this process.

Declining semen quality and steadying seminal plasma ions in heat-stressed boar model

Purpose

There are increasing concerns about infertility of male exposure to high environmental temperatures. Nevertheless, the relationship between heat and accessory sex gland secretion underlying the high ambient temperature-induced poor semen quality has not yet been addressed.

Methods

In the present study, five boars were used as an animal model to evaluate semen quality and the secretory function of accessory sex glands. After the boars received 3 days of heat exposure, semen collection was standardized to 18 continual times with a 3-day interval to determine the semen variables of semen volume, semen concentration, abnormal spermatozoa, seminal plasma composition, and testosterone level in the seminal plasma and serum.

Results

The total sperm count was lowest by the end of week 2. The higher abnormal spermatozoa percentage were observed by the end of week 2 and persisted until week 6 after heat exposure. Additionally, there was no significant change in semen volume, testosterone level, and concentrations of ions and total protein in the seminal plasma before and after heat exposure.

Conclusions

A single 3-day heat exposure caused poor semen quality, but did not disturb accessory sex gland secretion in boars. Declining semen quality might be mainly due to the damaged germ cells, which were sensitive to elevated temperature in hot summer months.

Estereologia das glândulas bulbouretrais do coelho (Oryctolagus cuniculus) e da cobaia (Cavia porcellus)

As glândulas bulbouretrais (GBU) no coelho (Oryctolagus cuniculus) e na cobaia (Cavia porcellus) desempenham um papel importante na fisiologia reprodutiva. No entanto, seus aspectos histológico e estereológico são escassos. Assim, o objetivo desta pesquisa foi comparar características estereológicas entre as GBU do coelho e da cobaia como um primeiro passo para a compreensão das variáveis morfométricas que participam nos processos reprodutivos. Foram utilizados 5 coelhos e 5 cobaias adultos machos, saudáveis, obtidos do Biotério da Universidade de La Frontera, Temuco, Chile. A região pélvica foi dissecada isolando-se a GBU de cada animal. Determinou-se o peso e o volume de cada glândula. Estas foram fixadas em formalina tamponada durante 24 horas e incluídas em paraplast. Cortes seriados de 4 μm de espessura foram corados com HE para análise estereológica. A média de células glandulares na GBU do coelho foi 19,50 x 10(5)mm³ (DP 2,35) e da cobaia 10,57 x 10(5)mm³ (DP 2,07) e a porcentagem média de tecido glandular foi de 25,52% (DP 2,20) e 17,20% (DP 3,33), respectivamente. Todos os parâmetros estereológicos comparados tiveram uma diferença estatisticamente significativa (p<0,0001). Estas diferenças poderiam ser explicadas porque há maior proximidade celular do epitélio secretor, menor diâmetro do lúmen dos ácinos e da relação núcleo citoplasma na GBU do coelho. Assim, os ácinos da GBU apresentam maior quantidade de células por mm³ do que na GBU do coelho. Estes parâmetros podem ser influenciados por fatores hormonais, etários, sazonais e ambientais, entre outros. Considerar as características morfológicas da GBU nesses animais poderia condicionar o êxito da reprodução por parte do macho.

Anatomical and immunohistochemical characteristics of the prostate gland in the greater cane rat (Thryonomys swinderianus)

This study examined the morphology and immunohistochemical features of the prostate gland in 15 captive-reared male greater cane rat of known reproductive and medical history. Samples of the glands were taken after gross examination and routinely prepared for both histological and ultrastructural analysis. Immunohistochemistry was also carried out on paraffin-embedded sections of the glands using rabbit polyclonal antibodies against oestrogen receptors (ERα and ERβ) and mouse monoclonal antibody for the progesterone receptor (PR). The prostate, which constitutes 0.04% of the body weight, was a paired, lobulated, brownish gland having three left and four right lobes that partly cover the pelvic urethra. Based on the amount and arrangement of the secretory epithelial folding and relative to their distances to the urethra, two histological zones, the central and peripheral, were identified. However, the epithelium of both zones was lined by predominantly simple cuboidal cells with occasional basal cells. The main ultrastructural features of these cuboidal cells were the presence of several nuclear pores on the nucleus, moderately well-developed, short microvilli and bleb-like apical projections, as well as inter-cellular lacunae seen between these cells and the basal cells. The cuboidal epithelial cells also showed positive nuclear staining for ERα and ERβ but not for PR. It is however interesting that the ERα-positive staining was more at the epithelial cells, which is uncommon. These findings highlight the peculiarities in the structure and ultrastructure as well as the unique expression of the oestrogen receptors in the prostate gland of the greater cane rat.

Histomorphological Studies on the Prostate Gland of Donkey Equus Asinus during Different Seasons

The objective of this study is to describe the histological and histochemical structures of the prostate gland during different seasons of the year. The experiment was carried out on the prostate gland of 24 sexually mature apparently healthy male donkeys (5 to 7 years) distributed over the four seasons of the year. The prostate gland was enveloped externally by a thick fibromuscular capsule. Fibromuscular septa arose from the deep aspect of the capsule dividing the prostate into variable numbers of lobules of different sizes and shapes. Each prostatic lobe was made up of compound tubuloalveolar glands and duct system. The secretory end pieces were lined with principal secretory cells with occasional few basal ones. The principal cells varied from columnar to cuboidal in shape, depending upon the studied season. The principal cells showed PAS-positive reactivity. Seasonal variations were observed in the height of the principal cell lining the secretory end pieces, in the interstitial tissue/glandular tissue ratio, and in the PAS reactivity in the principal cells. In conclusion, the prostate gland of donkey appeared more active during spring. This reactivity decreased during other seasons of the year. Minimal reactivity was recorded during winter.

Epithelial Bmp (Bone morphogenetic protein) signaling for bulbourethral gland development: a mouse model for congenital cystic dilation

The bulbourethral gland (BUG) is a male-specific organ, which secretes part of the semen fluid. As the BUG is located in the deep pelvic floor, its developmental process is still unclear. Bone morphogenetic protein (Bmp) signaling plays pivotal roles in various organs. However, the function of Bmp signaling for BUG development is still unclear. The present study aimed to elucidate the role of Bmp signaling in the development of the BUG. We observed the prominent nuclear accumulation of phosphorylated (p) SMAD1/5/8, the downstream molecules of Bmp signaling, during BUG epithelial development. These results suggest that Bmp signaling contributes to BUG development. Bmp receptor1a (Bmpr1a) is known as the major type 1 signal transducer in some organogeneses. To analyze the Bmp signaling function for BUG development, we examined epithelial cell-specific Bmpr1a gene conditional mutant mice utilizing the tamoxifen-inducible Cre recombinase system. We observed cystic dilation and epithelial hyperplasia of the BUG in the Bmpr1a conditional knockout mice. The mutant cystic BUG specimens also showed inflammatory lesions. These BUG abnormalities resembled some of the BUG malformations observed in human congenital syndromes. The current study suggests that Bmp signaling possesses an essential role in BUG development and homeostasis. This would be the first report showing that the mutation of the Bmpr1a gene in the BUG epithelia phenocopied some abnormalities of human congenital syndromes affecting the BUG duct.