Evidence for production and functional activity of nitric oxide in seminiferous tubules and blood vessels of the human testis

Previous studies have demonstrated that nitric oxide (NO) influences Leydig cell function. Here we provide evidence for NO production and activity in seminiferous tubules and blood vessels of the human testis. By immunohistochemistry, the soluble guanylyl cyclase (sGC), the intracellular NO receptor, and the second messenger, cyclic guanosine monophosphate (cGMP), were detected in myofibroblasts of the peritubular lamina propria in Sertoli cells, as well as in endothelial and smooth muscle cells of testicular blood vessels. Performed with isolated tubules and blood vessels, the biological activity of sGC could be proved by cGMP generation in response to treatments with the NO donor, sodium nitroprusside. The endothelial and neuronal subtypes of NO synthase (NOS) were localized immunohistochemically to the same cell types that express sGC and cGMP. In isolated tubules and vessels, the presence of endothelial NOS and neuronal NOS was confirmed by immunoblotting, and NOS activity was demonstrated by decreased cGMP production upon incubation with the NOS inhibitor L-nitro arginine methylester. These findings show that peritubular cells, Sertoli cells, and testicular blood vessels may be sites of NO production and activity, possibly involved in relaxation of seminiferous tubules and blood vessels to modulate sperm transport and testicular blood flow, respectively.     

Microarchitecture of the cat testis with special reference to Leydig cells: a three-dimensional study by alkali maceration method and scanning electron microscopy

Testes from adult cats were studied by means of parallel transmission and scanning electron microscopy (SEM) after NaOH digestion technique, which selectively removed connective tissues or cells. The testis is covered by a dense fibroconnective tunica albuginea that partially divides the organ in lobules by sending septa into the parenchyma. The lamina propria of the seminiferous tubules consisted of one or two rows of cells. The interstitium was made up of randomly arranged collagen bundles. The most significant feature was the numerous Leydig cells rich in lipid droplets and displaying epithelioid features. Following alkali digestion and SEM these cells showed a cord-like arrangement. The cords were formed by one or two closely apposed cells, in between which some labyrinthine or canalicular-like spaces were left that in some areas opened in wide perivascular spaces. This particular arrangement of Leydig cells and the labyrinthine intercellular spaces is very likely designed to improve cell secretion of hormones, facilitating their transport into the blood, as well as the traffic of fluids and metabolites. The present techniques allowed the visualization of a real three-dimensional testicular microarchitecture and microtopography, not detectable with other methods. Such a study may help to better highlight the testicular morphophysiology.     

Classification of several types of maturational arrest of spermatogonia according to Sertoli cell morphology: an approach to aetiology

Bilateral testicular biopsies and clinical histories from 34 adult men with maturational arrest of spermatogonia were examined. According to the morphology of Sertoli cell nuclei, five testicular types of spermatogonial maturational arrest were established. In type I lesion, Sertoli cells resembled the immature Sertoli cells of infant testes. These cells had a round, regularly outlined, dark nucleus with a small nucleolus. The seminiferous tubules showed no apparent lumen and a poorly developed lamina propria lacking in elastic fibres. This lesion was found in patients exhibiting a eunuchoid phenotype, with small tests and low serum levels of gonadotrophins and testosterone (hypogonadotrophic hypogonadism). Type II lesion showed morphologically normal, mature, adult Sertoli cells which had a pale, irregularly outlined nucleus, many often triangle-shaped, with a large, centrally located nucleolus. The seminiferous tubules were reduced in diameter and showed a few spermatocytes and spermatids. This lesion was found in patients with varicocoele, epididymitis, testicular trauma or idiopathic infertility. Serum FSH levels were normal or increased while LH and testosterone levels were normal. In type III lesion, Sertoli cells resembled the involuting Sertoli cells found in the testes of aging men, and displayed very infolded nuclei, with abundant dense chromatin patches and a large nucleolus. The seminiferous tubules showed a slightly dilated lumen and a normal tubular wall. The most relevant clinical findings in patients with this lesion were alcoholism, varicocoele, falciform cell anaemia, epididymitis and germ cell tumour. Serum follicle stimulating hormone (FSH) levels were normal or increased while luteinizing hormone (LH) and testosterone levels were normal. Type IV lesion Sertoli cells presented with a de-differentiated appearance. These cells had a small, round euchromatic nucleus with a small nucleolus and vacuolated cytoplasm. The seminiferous tubules were devoid of lumen or ectatic, and the tubular wall was thick and contained abundant elastic fibres. This lesion was characteristic of patients who underwent hormonal treatment because of prostatic carcinoma or sex change. Type V lesion showed abnormally differentiated, probably dysgenetic, Sertoli cells which had a round to ovoid regularly outlined nucleus, with small heterochromatin granules, and the number of these cells was increased. The seminiferous tubules had a central lumen, or were ectatic with vacuolated Sertoli cells, and the amount of elastic fibres was decreased. The most relevant clinical finding in patients with this lesion was orchidopexy. Serum FSH and LH levels were normal or slightly increased. These findings indicate that spermatogonial maturational arrest is associated with a characteristic Sertoli cell morphology that can be easily identified. This morphology may shed light on the aetiology of the disorder, and be useful for establishing the prognosis and bases for treatment in subfertile patients.     

Experimental study on earlier thrombogenic process in thrombin induced retinal venous obstruction in rabbit eye]

The purpose of this study was to morphologically investigate the thrombogenic process in the early stage of retinal venous obstruction development. Venous obstruction was induced by transadventitial instillation of thrombin (5 units) given to the rabbit retinal vessels via a sclerovitreous route. The changes were studied by ophthalmoscopy, fluorescence microscopy combined with an intravenously injected gelatin fluorescein preparation technique as well as light and electron microscopy. No ophthalmoscopic change was seen within 1 hr after thrombin instillation. Three hour after thrombin instillation, focal narrowing of retinal arterioles was found with intraluminal platelet aggregation and rouleaux formation of erythrocytes. On electron microscopy, a large number of monocytes was observed in the lumina and subendothelial space of a pericytic venule having a partial endothelial defect as well as monocyte adhesion to its luminal surface. At more than 6 hrs, subendothelial thrombi were observed in the venules without any endothelial lesion while no change was observed in the arterioles, capillaries and pericytic venules. These findings suggested the possibility of participation of the arteriolar lesion in the occurrence of retinal venous obstruction and the role of endothelial lesions caused by blood stasis in subendothelial thrombogenesis.     

Testicular calcifications: incidence, histology and proposed pathological criteria for testicular microlithiasis

PURPOSE: Testicular microlithiasis is a clinical syndrome in which men present with innumerable testicular calcifications. Indirect evidence suggests that this syndrome may be associated with an increased risk of germ cell neoplasia. The incidence and types of testicular calcification in normal and diseased testes is unknown. MATERIALS AND METHODS: A series of 131 orchiectomy specimens were reviewed, including 79 germ cell tumors, and 100 entirely embedded autopsy testes in men with no known testicular pathology. RESULTS: Two types of calcifications were identified. Hematoxylin bodies, consisting of amorphous calcific debris, were present in 6 cases associated with germ cell tumors. In contrast, laminated calcifications were found not only in association with germ cell tumors (35 cases), but also in 2 of 4 cryptorchid testes and 6 of the remaining 145 testes (4%). Of these calcifications 61% were multiple. When laminated calcifications were associated with germ cell tumors there was an increased incidence of extension beyond the tunica albuginea (43 versus 21%) and lymphatic invasion (52 versus 17%, p = 0.046 and 0.012, respectively). CONCLUSIONS: Testicular calcifications are heterogeneous. Hematoxylin bodies are specific for germ cell tumors but laminated calcifications, while more common in germ cell tumors, also occur in otherwise normal testes. The pathological criteria for testicular microlithiasis should include the identification of multiple laminated calcifications within seminiferous tubules.     

Laparoscopic and histologic evaluation of the inguinal vanishing testis

OBJECTIVES: Visual inspection of the spermatic cord vessels and vas deferens during laparoscopy now frequently determines further treatment. We set out to explore the implications of atretic spermatic cord vessels and vas deferens entering the inguinal ring, a finding noted on laparoscopic examination in some patients with a nonpalpable testis, and that we refer to as the inguinal vanishing testis. METHODS: We reviewed our series of 35 patients with nonpalpable testes with regard to the laparoscopic, surgical, and histopathologic findings of the involved gonadal structures. RESULTS: We noted atretic vessels and vas deferens entering the inguinal ring in 14 patients in this series. All 14 patients underwent open inguinal exploration. Histopathologic findings revealed fibrosis and hemosiderin deposits alone in 13 patients. One specimen had a microscopic focus of residual seminiferous tubules. No specimen contained dysgenetic gonadal tissue. CONCLUSIONS: We submit that patients with inguinal vanishing testes do not need to undergo inguinal exploration to remove residual testicular tissue. Only rarely will viable seminiferous tubules be found, so the risk of malignant degeneration is remote. The histopathologic findings suggest that the inguinal vanishing testis occurs secondary to a vascular accident in utero or in the neonatal period.     

Klinefelter syndrome with hypogonadotropic hypogonadism and absence of Leydig cells

Klinefelter's syndrome is characterized by hypergonadotropic hypogonadism, 47,XXY karyotype, gynecomastia, azoospermia and testicular atrophy with hyalinization of seminiferous tubules and hyperplasia of Leydig cells. Some cases of Klinefelter's syndrome with unexplainably low levels of gonadotropins have been reported in the literature. Two additional cases of Klinefelter's syndrome with hypogonadotropic hypogonadism and absence of Leydig cells are described.     

Testing the potential of sodium fluoride to affect spermatogenesis: a morphometric study

This study provides quantitative information on the effect of sodium fluoride (NaF) on the testes of F1 generation male rats exposed in utero and during lactation to NaF at one of four concentrations (25, 100, 175, 250 ppm). At weaning, the F1 generation males were exposed to NaF in their drinking water for 14 weeks, after which time testicular tissues were perfusion-fixed with glutaraldehyde and observed after being embedded in plastic. The seminiferous tubules comprised 89%, 87%, 88%, 88% and 88% of the total testis volume while the interstitial space occupied 9.3%, 11.2%, 10.2%, 9.8% and 9.9% of the total testis volume for the 0, 25, 100, 175 and 250 ppm NaF treatment groups, respectively. Statistically significant differences between control and NaF-treated rats were not observed with respect to absolute volume of the seminiferous tubules, interstitial space, Leydig cells, blood vessels boundary layer, lymphatic space, macrophages, tubular lumen or absolute tubular length and absolute tubular surface area, mean Sertoli cell nucleoli number per tubular cross-section, mean seminiferous tubule diameter and the mean height of the seminiferous epithelium. A statistically significant decrease in the absolute volume and volume percent of the lymphatic endothelium was observed in the 175 and 250 ppm NaF-treated groups and in the testicular capsule in the 100 ppm NaF-treated groups. The significance of this finding is unknown at the present time. Overall, the quantitative information obtained suggests that exposure to NaF at the doses used in the present study does not adversely affect testis structure or spermatogenesis in the rat.     

Tunica propria in chronic allergic rhinitis. Electron-microscopic study. I. The nasal blood vessels

The fine structure of human nasal blood vessels was studied in 15 chronic allergic patients. The venules showed gaping of the interendothelial junctions and lamination of the basal lamina. The capillaries displayed numerous endothelial cytoplasmic processes. The arteriolar walls showed thinning and destructive changes. A reciprocal relation between the vascular endothelium and its basal lamina was deduced.     

An opportunity for exploitation of research in biomedical engineering: the EC Life Sciences Demonstration Projects

The morphology of the ureter of the duck was investigated, using histological, SEM and TEM techniques. The inner perimeter, the total thickness of the ureteral wall and the thickness of each uretral layer were measured. The epithelium was tall columnar and pseudostratified along all the tracts of the ureter and showed a high muco-secretive activity. The lamina propria contained numerous capillaries and aggregates of leucocytes and macrophages. Throughout the lamina propria there was a dense plexus of nerves. Some denuded single nerve fibres were observed between the epithelial basal cells. A plexus of nerves was also observed in the tunica muscularis. The ostium cloacale ureteris opened on a well-developed papilla in the dorsal region of the urodeum. The total thickness of the ureteral wall, the thickness of the lamina propria and the tunica muscularis, and the inner perimeter progressively increased towards the ostium. The above observations suggest that the avian ureter plays an important role in the modification of the urine coming from medullary cones, and in emission of the urine into the cloaca.     

Ultrastructure of arterioles in the cat brain

A total of 110 arterioles were examined in the brains of cats; different sites were studied including the cortex, putamen, pons and crus cerebri. No internal elastic laminae were seen in the subendothelial space, although occasional fragments of elastic material were present in the larger arterioles. The media was composed of one, two or three layers of smooth muscle cells which interlocked in such a way that the vessel wall thickness was constant. Numerous tight junctions were seen between adjacent smooth muscle cells and between the endothelium and smooth muscle cells. Apart from the usual cell organelles, the smooth muscle cells of arterioles had numerous dense patches on the cell surface. The structure of the adventitia varied according to the diameter of the vessel and the site in the brain; it contained adventitial cells, bundles of collagen fibres and nerve fibres. Innervation of arterioles was more constant in the brain stem than in the cortex. Metarterioles had less specialised, atypical smooth muscle cells, a discontinuous media and numerous, extensive myoendothelial tight junctions; they were not innervated by nerve fibres. The diameter of metarterioles was less than 10 micronm whereas that of arterioles was 10-45 micronm. The possible functional aspects of arteriolar innervation are discussed.     

Hospital development and the performance of organ procurement organizations

Light microscopical studies on the uptake of blood-borne horseradish peroxidase (HRP) in large areas of the testis have been scarce because of the difficulty of staining HRP in testes with well-preserved morphology. However, observation of exogenous HRP in all areas of the testis enables detection of regional tissue injury induced by toxic chemicals or immunization. In the present study, the localization of blood-borne HRP in the murine testis was investigated light microscopically using plastic-embedded testes and post-embedding histochemical methods. Mice were injected intravenously with HRP, and then perfused with 2.5% glutaraldehyde and 3% paraformaldehyde in 0.1 M phosphate buffer. The fixed testes were immediately removed, dehydrated, and then embedded in plastic without cutting them into small pieces. The prepared sections treated by the diaminobenzidine method exhibited intense HRP activity with well-preserved testis morphology. It was noted that many interstitial macrophages had endocytosed HRP. In particular, HRP-endocytosing macrophages were concentrated around the tubuli recti. The testicular capsule, containing many lymphatic capillaries and vessels, was also loaded with HRP. In the subcapsular interstitium, free HRP in the lymph space accumulated, but the staining intensity was weak compared to that in testicular macrophages. No HRP infiltration into the lumen of the seminiferous tubules was observed at the light microscope level; however, HRP staining was detected in tubular walls and epithelial cells lining the rete testis and tubuli recti, indicating that these regions are permeable to HRP.     

Efficacy of octreotide in diarrhoea due to Vibrio cholerae: a randomized, controlled trial

The ultrastructure of autonomic nerve fibers and terminal varicosities is described in relation to the lamina propria of the human seminiferous tubules during childhood (age 3 to 10 years). Autonomic nerve varicosities are classified as: Type I with numerous small (30-60 nm) agranular vesicles and variable numbers of large (100 nm) granular vesicles, and Type II with numerous small (30-60 nm) granular vesicles and sporadic large granular vesicles. These two varicosity types are consistent in morphology with cholinergic and adrenergic nerve terminals, respectively. Nerve varicosities are found, associated with Schwann cells, in proximity to the cells of the lamina propria. Although not found in direct "synaptic' contact, these autonomic endings are often within a few hundred nanometers of the cellularity of the lamina propria. The Schwannian sheath is interrupted over the varicosities at these sites and occasionally the terminal varicosities are totally lacking a Schwann sheath. These findings are consistent with the structural relationship of autonomic nerve "terminals' and effector in other endocrine and non-endocrine systems. This is the first evidence of adrenergic nerve varicosities in proximity to the lamina propria in humans (at any age). Evidence is also presented which suggests a locational difference in the distribution of cholinergic (Type I) and adrenergic (Type II) nerve varicosities in this region, with only cholinergic endings observed directly adjacent to the basal lamina of the seminiferous tubules.     

Follicle-stimulating hormone in azoospermia in prediction of spermatogenic patterns

Follicle-stimulating hormone (FSH) is considered to be the most important plasma hormone correlated with spermatogenesis. Elevated FSH plasma levels were shown to be associated with complete damage to testicular seminiferous tubule germinal epithelium. Recently, there have been conflicting reports with regard to the value of FSH plasma levels in predicting seminiferous tubule histology in the azoospermic patient and hence, as a guide for therapy in assisted reproduction using testicular sperm retrieval. The aim of this study was to evaluate whether FSH plasma levels can predict spermatogenic pattern in the testes of the azoospermic infertile patient. 69 infertile men with non-obstructive azoospermia and 18 with very severe oligospermia were studied. In all, plasma levels of testosterone, free testosterone, prolactin, luteinizing hormone and follicle-stimulating hormone were measured by enzyme immunoassay. In the azoospermic patients the seminiferous tubule spermatogenic pattern was determined in testicular aspirates obtained by multiple fine needle aspiration and categorized according to the most mature spermatogenic cell type in the aspirates: Sertoli cells only, spermatogenic maturation arrest or full spermatogenesis. There were no significant differences in plasma levels of any hormone measured except in very severely oligospermic and azoospermic patients. Both normal and elevated levels were detected in all, regardless of seminiferous tubule cytological pattern or plasma FSH in azoospermic patients. It is concluded that plasma levels of FSH can not be used as a predictive parameter, neither for the presence of spermatozoa nor for any other seminiferous tubule cytological pattern in azoospermic infertile men. They cannot serve as guides for selection of azoospermic men for trials of testicular sperm retrieval in assisted reproduction.     

Radiological and functional outcome after anterior lumbar interbody spinal fusion

The efficacy of hCG treatment was studied in 182 cryptorchid patients. The efficacy of the treatment correlated with the initial position of the testis. None of the abdominal testes reached a normal position, whereas 90% of high scrotal testes descended during the treatment. Fifty-four boys who were treated unsuccessfully with hCG and 29 untreated boys were biopsied. The biopsies were performed on 32 scrotal and 87 maldescended testes to examine the state of the organ and the effects of hCG treatment. In biopsies, the volume densities of seminiferous tubules, interstitial tissue and blood vessels were counted, and the sections screened for interstitial bleeding. Significant differences between scrotal and maldescended testes were found in all of the volume densities measured. Interstitial bleeding occurred rarely in scrotal testes, whereas in maldescended testes it was frequently apparent. hCG treatment induced a significant increase in the volume density of both interstitial tissue and blood vessels. Even though the hCG treatment induced measurable, possibly harmful, changes both in scrotal and maldescended testes, our data do not prove that hCG treatment causes permanent damage to the testis.     

The radiation hybrid database

The objective of this study was to evaluate morphological characteristics and testicular function of boars with different endogenous concentrations of FSH. Boars were selected at 6 mo of age on the basis of mean FSH concentrations in plasma collected at 4, 5, and 6 mo of age. Boars were classified within half-sibling families based on whether they had high concentrations of FSH (HiFSH, > 500 ng/ml, n = 9) or low concentrations (LoFSH, < 500 ng/ml, n = 7). At 14.5 mo, testes were collected, fixed, sectioned at 1 microm, and evaluated for morphological characteristics. Boars with LoFSH had larger (p < 0.01) testicular and epididymal weights than boars with HiFSH, greater (p < 0.01) daily sperm production per gram of testis, and greater total daily sperm production per boar. Testes of boars with LoFSH had a greater (p < 0.03) volume percentage of seminiferous tubules, a lesser percentage (p < 0.03) of Leydig cells, and a somewhat lesser (p = 0.06) percentage of vascular structures than testes of boars with HiFSH. Testes of boars with LoFSH had greater (p < 0.01) total tubule volume and tubule length than testes of boars with HiFSH. There were no differences (p > 0.70) in volume, diameter, or total number of Leydig cells or in total interstitial volume in testes (p > 0.41) of these two groups. Production of testosterone in vitro per paired testis and per million Leydig cells was not different (p > 0.65) between boars with HiFSH or LoFSH. Greater concentrations of FSH in blood plasma were negatively associated with development of seminiferous tubules and spermatogenic efficiency, whereas Leydig cell development was not different in boars of these two groups.     

Embryonal morphogenesis of the intraorgan circulatory bed, lymphatic outflow pathways and innervation structures

Development of the circulation bed in human embryogenesis is brought about by a loop-like growth of vessels manifesting in proliferation, integration and morphofunctional transformation of the vascular loops. Proliferation of the loops ensures the blood inflow and reflux at all levels while their integration is followed by formation of hemocirculation system with appearance of the connective and major capillaries which serve the basis for development of true capillaries and capillary network in which precapillary arterioles and postcapillary venules can be distinguished. Hemocirculation system is completed by formation of the arteriolar and venular collaterals and arteriolo-venular anastomoses. Non-participation in the angiogenesis of the autogenic vessel endotheliocytes and their widespread necrosis give grounds to suggest that they are genetically condemned to death. Development of lymph vessels and innervation occurs simultaneously and together with blood vessels by mechanism of their centrifugal growth.     

A retrospective drug utilization evaluation of antihyperlipidaemic agents in a medical centre in Taiwan

The interstitial tissue of the testis was studied in gonadally active and gonadally inactive domestic fowl (Gallus gallus domesticus), guinea-fowl (Numida meleagris), duck (Anas platyrhynchos) and Japanese quail (Coturnix coturnix japonica). Gonadal inactivity in the fowl was induced by a single subcutaneous injection of 50 mg oestradiol benzoate. The structure of this tissue was similar in all the birds studied. Lymphatic vessels were mostly thin and meandered between the peritubular tissue peripherally and the centrally located blood vessels, Leydig cells and macrophages. The basal lamina rested on a closely associated homogeneous microfibrillar layer free of collagen fibres. The myofibroblast layer was several cells thick, and quite compact. The basal lamina of gonadally resting birds was highly irregular, relatively electron-dense, contained electron-lucent globules, and sent numerous finger-like processes or plicae into the seminiferous epithelium, particularly into the Sertoli cells. The Leydig cells were few but typical in structure. In gonadally inactive birds they accumulated lipid droplets, dense heterogeneous bodies, probably lysosomes, and appeared to degenerate. The avian testicular interstitium is similar to that of the human and cat in possessing a multi-layered myofibroblast component, and to that of the rodent in possessing a small number of Leydig cells, as well as in the location of the lymphatic vessels. Thus the bird combines characteristics of the interstitium found variably in mammals.     

Growth of testes and testicular morphology after eight generations of selection for increased predicted weight of testes at 150 days of age in boars

Weights of testes and epididymides, body weight, and morphometric measurements of testicular tissue of 75 boars of a line selected for eight generations for predicted weight of testes at 150 d of age and 75 boars of a randomly selected control line were used to evaluate the effects of selection on testicular development at 70, 100, 130, 160, and 450 d of age (n = 15 boars per line per age). Body weights for boars of the select and control line did not differ (P < .05) and the shape of the body growth curve was similar for both lines. Boars of the select line had larger testes than control boars at each age (P < .05), but there was a significant line x age interaction. The percentage increase of the select line mean over the control mean for weight of testes was 37% at 70 d, a maximum of 120% at 100 d, and 25% at 450 d. The percentage of the testes made up of seminiferous tubules differed between lines (P < .01). Lines had similar means of approximately 28% at 70 d and 71% at 450 d, but the mean for the select line was larger between 100 and 160 d of age; the greatest difference was 11.6% (control = 43.7, select = 55.3%) at 100 d. After 70 d of age, select-line boars had a greater percentage of seminiferous tubules with lumens that contained elongated spermatids (P < .10).(ABSTRACT TRUNCATED AT 250 WORDS)     

Immunohistochemical demonstration of a testicular substance related to luteinizing hormone-releasing hormone

A substance related to luteinizing hormone-releasing hormone was demonstrated, by immunohistochemical procedures, in the cytoplasm of interstitial cells within the rat testes. In many seminiferous tubules, nuclei of spermatogonial cells were also immunopositive. Both cytoplasmic and nuclear fractions of testicular homogenates contain immunoreactive compounds, and this report identifies which cell types contain this substance. The localization of a peptide hormone within the nucleus of a target cell population may indicate its mode of action.