The inflammasome NLRP3 plays a dual role on mouse corpora cavernosa relaxation.

NLRP3 plays a role in vascular diseases. Corpora cavernosa (CC) is an extension of the vasculature. We hypothesize that NLRP3 plays a deleterious role in CC relaxation. Male C57BL/6 (WT) and NLRP3 deficient (NLRP3-/-) mice were used. Intracavernosal pressure (ICP/MAP) measurement was performed. Functional responses were obtained from CC strips of WT and NLRP3-/- mice before and after MCC950 (NLRP3 inhibitor) or LPS + ATP (NLRP3 stimulation). NLRP3, caspase-1, IL-1ß, eNOS, nNOS, guanylyl cyclase-ß1 (GCß1) and PKG1 protein expressions were determined. ICP/MAP and sodium nitroprusside (SNP)-induced relaxation in CC were decreased in NLRP3-/- mice. Caspase-1, IL-1ß and eNOS activity were increased, but PKG1 was reduced in CC of NLRP3-/-. MCC950 decreased non-adrenergic non-cholinergic (NANC), acetylcholine (ACh), and SNP-induced relaxation in WT mice. MCC950 did not alter NLRP3, caspase-1 and IL-1ß, but reduced GCß1 expression. Although LPS + ATP decreased ACh- and SNP-, it increased NANC-induced relaxation in CC from WT, but not from NLRP3-/- mice. LPS + ATP increased NLRP3, caspase-1 and interleukin-1ß (IL-1ß). Conversely, it reduced eNOS activity and GCß1 expression. NLRP3 plays a dual role in CC relaxation, with its inhibition leading to impairment of nitric oxide-mediated relaxation, while its activation by LPS + ATP causes decreased CC sensitivity to NO and endothelium-dependent relaxation.

Stereological analysis of elastic fibers of the corpus cavernosum of rats during the aging process.

PURPOSE: To evaluate changes in the quantity of elastic fibers in the corpora cavernosa of rats during the natural aging process, and to assess the degree of this change by determining volumetric density (Vv) at different ages via stereological analysis. METHODS: Forty-eight rats, raised under similar conditions, were subjected to the natural aging process and divided into four groups (G1 to G4), according to age at the time of penectomy (6, 9, 12, and 24 months, respectively). Histological sections of the middle segment of the penis were stained with Weigert's resorcin-fuchsin, and the volumetric density (Vv) of elastic fibers of the corpora cavernosa were determined via stereological analysis. RESULTS: There were no statistically significant differences in Vv among groups G1, G2, and G3. These three groups were therefore considered as a single group. The mean Vv of this group showed a statistically significant reduction compared to that of G4 (0.16 vs. 0.11, p<0.05). CONCLUSION: Natural aging in rats was responsible for a reduction in volumetric density of elastic fibers of the corpora cavernosa (approximately 30% decrease in Vv) during senescence.

Stereological analysis of elastic fibers of the corpus cavernosum of rats during the aging process

Abstract Purpose To evaluate changes in the quantity of elastic fibers in the corpora cavernosa of rats during the natural aging process, and to assess the degree of this change by determining volumetric density (Vv) at different ages via stereological analysis. Methods Forty-eight rats, raised under similar conditions, were subjected to the natural aging process and divided into four groups (G1 to G4), according to age at the time of penectomy (6, 9, 12, and 24 months, respectively). Histological sections of the middle segment of the penis were stained with Weigert's resorcin-fuchsin, and the volumetric density (Vv) of elastic fibers of the corpora cavernosa were determined via stereological analysis. Results There were no statistically significant differences in Vv among groups G1, G2, and G3. These three groups were therefore considered as a single group. The mean Vv of this group showed a statistically significant reduction compared to that of G4 (0.16 vs. 0.11, p<0.05). Conclusion Natural aging in rats was responsible for a reduction in volumetric density of elastic fibers of the corpora cavernosa (approximately 30% decrease in Vv) during senescence.

Effects of Vitamin D Restricted Diet Administered during Perinatal and Postnatal Periods on the Penis of Wistar Rats.

Vitamin D deficiency is common in pregnant women and infants. The present study aimed to investigate the effects of vitamin D restricted diet on the Wistar rats offspring penis morphology. Mother rats received either standard diet (SC) or vitamin D restricted (VitD) diet. At birth, offspring were divided into SC/SC (from SC mothers, fed with SC diet) and VitD/VitD (from VitD mothers, fed with VitD diet). After euthanasia the penises were processed for histomorphometric analysis. The VitD/VitD offspring displayed metabolic changes and reduction in the cross-sectional area of the penis, corpus cavernosum, tunica albuginea, and increased area of the corpus spongiosum. The connective tissue, smooth muscle, and cell proliferation percentages were greater in the corpus cavernosum and corpus spongiosum in the VitD/VitD offspring. The percentages of sinusoidal spaces and elastic fibers in the corpus cavernosum decreased. The elastic fibers in the tunica albuginea of the corpus spongiosum in the VitD/VitD offspring were reduced. Vitamin D restriction during perinatal and postnatal periods induced metabolic and structural changes and represented important risk factors for erectile dysfunction in the penis of the adult offspring. These findings suggest that vitamin D is an important micronutrient in maintaining the cytoarchitecture of the penis.

Acellular human glans extracellular matrix as a scaffold for tissue engineering: in vitro cell support and biocompatibility.

UNLABELLED: Diseases of the genitourinary tract can lead to significant damage. Current reconstructive techniques are limited by tissue availability and compatibility. This study aims to assess if the decellularized human glans can be used as a biomaterial for penile reconstruction. MATERIALS AND METHODS: Samples of the glans matrices were descellularized. We evaluate the presence of collagen type I and III, and elastic fibers. Biocompatibility assays were performed to assess the cytotoxic and non-cytotoxic interactions between the acellular matrix and 3T3 cells. The matrices were seeded with mesenchymal stem cells and were assessed for viability and integration of these cells. Biomechanical tests in native tissue, descellularized matrix and seeded matrix were performed to characterize their biomechanical properties. RESULTS: The tissue architecture of the decellularized matrix of human glans was preserved as well as the maintenance of the biomechanical and biological properties. The analyzes of glans seeded with mesenchymal stem cells revealed the integration of these cells to the matrices, and its viability during two weeks "in vitro". CONCLUSION: The decellularization process did not alter the biological and biomechanical characteristics of the human glans. When these matrices were seeded they were able to maintain the cells integrity and vitality.

Acellular human glans extracellular matrix as a scaffold for tissue engineering: in vitro cell support and biocompatibility

ABSTRACT Objectives: Diseases of the genitourinary tract can lead to significant damage. Current reconstructive techniques are limited by tissue availability and compatibility. This study aims to assess if the decellularized human glans can be used as a biomaterial for penile reconstruction. Materials and Methods: Samples of the glans matrices were descellularized. We evaluate the presence of collagen type I and III, and elastic fibers. Biocompatibility assays were performed to assess the cytotoxic and non-cytotoxic interactions between the acellular matrix and 3T3 cells. The matrices were seeded with mesenchymal stem cells and were assessed for viability and integration of these cells. Biomechanical tests in native tissue, descellularized matrix and seeded matrix were performed to characterize their biomechanical properties. Results: The tissue architecture of the decellularized matrix of human glans was preserved as well as the maintenance of the biomechanical and biological properties. The analyzes of glans seeded with mesenchymal stem cells revealed the integration of these cells to the matrices, and its viability during two weeks "in vitro". Conclusion: The decellularization process did not alter the biological and biomechanical characteristics of the human glans. When these matrices were seeded they were able to maintain the cells integrity and vitality.

Effects of castration and late hormonal replacement in the structure of rat corpora cavernosa.

The objective of the study was to evaluate, through quantitative methods, the structural alterations in the corpora cavernosa of rats submitted to orchiectomy as well as the role of late hormone replacement in overturning the possible structural alterations. Twenty-five male rats were assigned into 5 groups with 5 animals each and treated as follows: ORCHIEC-1 = submitted to orchiectomy and sacrificed after 1 month; C-1 = control group sacrificed after 1 month; ORCHIEC-2 = submitted to orchiectomy and sacrificed after 2 months; C-2 = control group sacrificed after 2 months; and T = submitted to orchiectomy, underwent testosterone replacement with testosterone undecanoate (100 mg/kg) after 1 month, and sacrificed after 1 month of hormonal replacement. Smooth muscle, collagen, and elastic system fibers of penile corpora cavernosa were quantified. There was a significant decrease in the absolute values of smooth muscle, sinusoidal space, and total area of corpora cavernosa after 2 months in the castrated group when compared with controls. Overall, regarding density, no significant differences were observed among the groups. The hormonal replacement with testosterone was able to reverse the alterations observed. The method used for this research allowed demonstrating that absolute values are reliable to quantify the structural alterations of corpora cavernosa structures. The results suggest that hormonal replacement, even when instituted at a late stage, is effective in reversing the corpora cavernosa's structural alterations produced by castration.

Intraepithelial plasma cells in the avian copulatory organ of two tinamou species: quantitative variation during the breeding season.

A recent observation concerning the phallus of the tinamou Nothura maculosa was the presence of cells resembling plasma cells within the epithelium of the fixed tubular portion. Owing to this unusual location of plasma cells, we studied the phalli of the tinamous N. maculosa and Rhynchotus rufescens to confirm the occurrence of intraepithelial plasma cells and to evaluate the seasonal variation in these cells. Abundant plasma cells were found within the epithelium of the fixed tubular portion of the phallus but not in the evertible portion. Migration of plasma cells from the adjacent connective tissue through the basement membrane and between the epithelial cells was frequent. Some plasma cells exhibited a rough endoplasmic reticulum with variable cisternal distension, containing fine, slightly electron-dense, granular material suggestive of immunoglobulin accumulation. An expressive increase of more than 800% in the number of intraepithelial plasma cells was found during the breeding season compared to the non-breeding season. By establishing the occurrence of intraepithelial plasma cells in the phallus and their seasonal variation, the results contribute to a better understanding of the role of these cells in the mucosal immune system of the reproductive tract of male birds.

Histological and histochemical aspects of the penial glands of Girardia biapertura Sluys, 1997 (Platyhelminthes, Tricladida, Paludicola).

Girardia biapertura was described with sperm ducts penetrating the penis bulb, subsequently opening separately at the tip of the penis papilla and receiving the abundant secretion of penial glands. In the present work, the penial glands of this species have been histologically and histochemically analysed, and four types of secretory cells are distinguished. The openings of the penial glands into the intrabulbar and intrapapillar sperm ducts, designated here as intrapenial ducts, allow for the distinction between three histologically differentiated regions. The most proximal region possibly corresponds to the bulbar cavity of other freshwater triclads whereas the median and distal portions correspond to the ejaculatory duct. The proximal region of the intrapenial ducts receives mainly the openings of a secretory cell type (type I) that produces a proteinaceous secretion. A second type of secretory cell (type II) that secretes neutral mucopolyssacharides opens into the median region of the intrapenial ducts. The distal portion of the ducts receives two types of secretory cells (types III and IV) which secret glycoprotein and glycosaminoglycans, respectively. Types III and IV open also directly into the male atrium through the epithelium of the penis papilla. A comparison with the results presented here and those of other authors for species of Girardia is provided and the importance of the study of the penial glands for taxonomic characterisation of freshwater triclads is emphasised.

Organization and relative content of smooth muscle cells, collagen and elastic fibers in the corpus cavernosum of rat penis.

PURPOSE: The corpus cavernosum smooth muscle and extracellular matrix are essential for normal penile erection and are implicated in erectile dysfunction. Although investigations of these issues have used the rat corpus cavernosum, organization of its components is to date not well known. We characterized and quantified the smooth muscle cells and the main extracellular matrix components of the rat corpus cavernosum. MATERIALS AND METHODS: Collagen, elastic fibers and smooth muscle cells were stained on paraffin sections of rat penises using sirius red and Gomori's reticulin, Weigert's resorcin-fuchsin and an anti-smooth muscle cells alpha-actin antibody, respectively. Stained components were then quantified by computer aided morphometry. RESULTS: Smooth muscle cells were restricted to the subendothelial space of corpus cavernosum and had a volumetric density of 9.1%. Collagen was thick, usually in transversely oriented bundles and was the most abundant component of the trabeculae with a volumetric density of 62.7%. Gomori's reticulin disclosed a meshwork of fibrils also in the subendothelial space but did not stain the thicker bundles. Volumetric density of elastic fibers was 4.9%, and at the periphery of the corpus cavernosum the fibers were parallel to the long axis of the penis, while in deeper regions most of them were transversely oriented and at different directions from those of collagen. CONCLUSIONS: Rat corpus cavernosum differs from that of humans by lesser amounts of smooth muscle cells, greater amounts of collagen and the presence of fibrillar collagen and smooth muscle cell subendothelial layers. Therefore, these differences should be considered when using the rat penis for studies on erection.

Morphology of the copulatory apparatus of the spotted tinamou Nothura maculosa (Aves: Tinamiformes).

The components of the copulatory apparatus of Nothura maculosa were identified and studied by means of dissections, parenteral latex injections and standard histological and histochemical techniques. N. maculosa possesses an intromittent phallus with a tubular cavity, within which a fixed base and a tubular portion can be distinguished. An ejaculatory groove, which is supported by a fibrous body, runs dorsally at the base of the phallus. The tubular portion of the phallus inserts into the fibrous body, the former possessing two continuous but morphologically distinct parts, one of which is eversible and is extruded during erection while the other is a fixed non-eversible glandular portion. The walls of both parts are formed by the mucosa, an intermediate layer of connective tissue containing a wide lymphatic space which surrounds the whole perimeter of the tube, and an external layer of dense connective tissue. The mucosa of the eversible portion, which lodges the phallic groove, is lined by a non-keratinized stratified squamous epithelium. In the fixed tubular portion, the tubular lumen is reduced in size, the phallic groove disappears, the mucosa becomes folded and there occurs an abrupt change to a pseudostratified columnar secretory epithelium. The copulatory apparatus of N. maculosa includes the vascular bodies of the phallus, which show morphofunctional continuity with the phallic structures, thus forming a single system involved in erection. On erection, the eversible portion of the phallus evaginates and emerges from the cloacal opening as a spiral shaped structure directed towards the left.

Collagen and elastic fibers in the penis of human fetuses at 28 weeks postconception.

OBJECTIVES: The extracellular matrix is a key element in penile function and pathology, yet little is known of its development. Herein we investigated the morphological organization of collagen and elastin in the corpora cavernosa and tunica albuginea of human fetuses. MATERIAL AND METHODS: The penises from 5 fresh human fetuses at 28 weeks postconception (WPC) were routinely fixed and embedded, and all staining procedures were carried out on paraffin sections. Collagen was evidenced by staining with: (1) Gomori's trichrome; (2) sirius red, followed by observation under polarized light, and (3) an antihuman collagen type-III antibody. Elastin and the whole elastic system were revealed using an antihuman elastin antibody and Weigert's resorcin fucsin, respectively. RESULTS: At this stage of fetal development, the albuginea is formed predominantly by dense bundles of collagen. Near the corpora cavernosa, the presence of type-III collagen was also observed. Weigert staining showed numerous fibers of the elastic system in the albuginea. Type-III collagen was found to be strongly positive in the cavernous trabeculae and in the connective sheath surrounding the central artery. Using Weigert staining and an immunolabeling method with primary antibody against human elastin, we found an important quantity of elastic system fibers in the trabeculae of the corpora cavernosa. CONCLUSION: In fetuses at 28 WPC the albuginea is formed predominantly by dense bundles of collagen. The trabecular structures of the corpora cavernosa present a significant quantity of type-III collagen and elastic system fibers.

Quantitative analysis of smooth muscle fibers in corpus cavernosum of human fetuses.

PURPOSE: Quantify objectively the normative distribution and the percentage of smooth muscle fibers in the corpus cavernosum of human fetuses with 24 weeks post-conception (WPC) of gestational age. MATERIAL AND METHODS: We studied 7 penises taken from 7 fresh human fetuses. We analyzed 5 randomized sections from each penis and in every section we analyzed 3 fields, totaling 15 fields per penis and 105 fields for the final results. Immunohistological staining for the smooth muscle fibers was used to accentuate the differences between the intracavernous structures (smooth muscle fibers and collagen fibers). The fields studied were digitized with a final magnification of 450X and a computerized analysis of the smooth muscle fibers was performed with image analyzer software. The percentage of smooth muscle fibers per standard square area was estimated and the mean value was used for each penis. RESULTS: The distribution of smooth muscle fibers in the corpus cavernosum of human fetuses with 24 WPC of gestational age ranged from 17.52% to 27.76% of the total area. The mean value was 22.72% and the standard deviation was 3.56. CONCLUSIONS: Our results show that the percentage of smooth muscle cells in corpus cavernosum of human fetuses with 24 WPC of gestational age is significantly smaller when compared with the data available for adult cadavers.