Studies on relationship between testicular capsule and sperm transport in rat testis

Aim: In SD rats, histological changes in the testis were observed after bilateral capsulotomy (of the tunica albuginea) in order to investigate the physiological role of the testicular capsule on sperm transport. Methods: Bilateral longitudinal capsulotomy was devised to disrupt the capsular contractile function. With this technique, only the tunica vaginalis and tunlca albuginea were slit open, leaving the tunica vasculosa intact to embrace the underlying testicular parenchyma. After capsulotomy, the structural changes in the seminiferous tubules, the transitional distal seminiferous segment, and the rete testis were observed. Results: In the capsulotomized testis, there was sperm retention at the transitional seminiferous segment and progressive degenerative changes in seminiferous tubules. Conclusion: The results clearly indicated that an intact testicular capsule was required for normal sperm transport from the seminiferous tubules into the rete testis. This is the first attempt to study the physiological role of the testicular capsule in intact animals.     

Effect of testicular capsulotomy on secretion of testosterone and gonadotrophins in rats

Aim: In order to clarify further the mechanisms underlying the effect of capsulotomy on testicular function, the levels of testosterone, LH and FSH were observed. Methods: Intratesticular testosterone levels and LH, FSH levels in the peripheral blood of normal, sham-operated and capsulotomized rats were detected by RIA. Results: After testicular capsulotomy, there was a progressive reduction in the testosterone level in the testicular venous blood together with a progressive increase in the LH and FSH levels in the peripheral blood from approximately 30 days post-capsulotomy. Morphological changes were observed at 5-10 days after capsulotomy, i.e., far ahead of the hormonal changes.Conclusion: The seminiferous tubular damage after testicular capsulotomy was not caused by the reduction in testosterone, and on the contrary, the hormonal change might be secondary to the morphological alterations. The increase in LH level most likely resulted from a negative feedback influence from the lowered testosterone level, while the increase in FSH secretion may be a feedback signal of the damaged seminiferous tubules. (Asian J Androl 2000 Dec;2:257-261)     

Immunohistochemical observation on luteinizing hormone in rat testes before and after testicular capsulotomy

Aim: In the testicular capsulotomized rats, although there was a significant increase in the luteinizing hormone (LH) levels, the secretion of testosterone remained low. In order to clarify the mechanisms of this phenomenon, the binding of endogenous LH to the testes were observed before and after testicular capsulotomy. Methods: Peroxidase-antiperoxidase (PAP) method was used to detect the binding of LH to the testes in rats. Results: An intense positive staining of LH was found in the Leydig cells of both the normal and sharn-operated control testes. However, at 40 d after operation, the LH immunoreactivity was decreased in the Leydig cells of the capsulotomized testis. By d 60, only very weak positive staining could be observed in these cells. Conclusion: A progressive reduction of endogenous LH binding to the testis occurred in the capsulotomized rat.     

Local regulation of Leydig cells by the seminiferous tubules. Effect of short-term cryptorchidism

Unilateral cryptorchism was induced in adult rats for 24 h, and its effect on testicular morphology and intratesticular testosterone concentration after hCG-stimulation were studied. In seminiferous, tubules from abdominal testes an increased number of degenerating germ cells was noted in stages XIV-III of the spermatogenic cycle and Sertoli cells contained an increased amount of lipid droplets in stages XIV-VIII. However, germ cells and Sertoli cells from tubules at other stages of the cycle appeared unaffected. In scrotal testes the size of peritubular Leydig cells varied in phase with the spermatogenic cycle. The largest cells were found adjacent to stage VII-VIII and the smallest adjacent to stage XI-XII. In abdominal testes no stage-dependent variation in the size of peritubular Leydig cells was seen. Perivascular Leydig cells were of equal size in abdominal and scrotal testes. The testicular testosterone concentration following stimulation with a low dose of hCG was significantly lower in abdominal testes. It is suggested that the seminiferous tubules locally modulate Leydig cell function and that the stage specific stimulatory influence from stage VII-VIII is rapidly lost during experimental cryptorchidism.     

Morphometric study on leydig cells in capsulotomized testis of rats

AIM: To further clarify the changes occurred in the testicular capsulotomized rats. METHODS: In testicular capsulotomized and sham-operated rats, the cross sectional area, the nucleus diameter and the number of Leydig cells were morphologically analyzed by the Vidas Image Processing System connected to a microscope. RESULTS: In the capsulotomized animals, the cross sectional area of Leydig cells was gradually increased from 30 days onwards. There was no obvious change in the nucleus diameter of Leydig cells. However, The Leydig cell number was significantly increased from day 30 onwards. CONCLUSION: In rats, testicular capsulotomy may induce hyperplasia/hypertrophy of Leydig cells in the testis.     

Mechanism of alcoholic testicular damage]

To observe the mechanism of alcoholic testicular damage, in a previous experiment we used weanling male SD rats aged 45 days, weighing about 200 g, and fed a liquid diet (Lieber's) containing 5% ethanol. The latter accounted for 36% of total caloric intake for 7 weeks, but did not result in testicular atrophy. In a later experiment, we used a liquid diet in which ethanol accounted for 46% of the total calorie count. It provided a high-fat, low-protein content which simulated the nutritional background of patients with alcoholic liver diseases. This diet resulted in testicular atrophy. Histological and biochemical changes accompanying this experimental testicular atrophy included the following: 1) The testes of alcohol-fed animals contained smaller seminiferous tubules with reduced numbers of total cells, but no degeneration was seen in the spermatids. 2) In the peritubular wall of the seminiferous tubules, we observed curvature, irregularities, infolding of the basement membrane, and lamellation of the lamina densa, as well as hyperplasia of collagen fibers in the tunica propria. 3) In the cytoplasm of the Sertoli cells, deposits of gigantic fat droplets and stratification of the mitochondria were observed. The permeability of the Sertoli cell tight junction was confirmed using the Lanthanum method. 4) Testosterone levels in both the serum and testes declined. 5) Lactate dehydrogenase-X (LDH-X) activity in the testes declined. 6) Low Km alcohol dehydrogenase (ADH) activity localized in the testicular interstitial tissue was increased. These results indicate that the composition of three major nutritional elements as well as alcohol concentration are important in the mechanism of alcoholic testicular damage, and this damage affects both the testicular interstitial cell and the seminiferous tubules, particularly the Sertoli cells and peritubular wall of the latter. In addition, the findings suggest that ADH is involved in alcohol metabolism in the interstitial cells of the testes.     

Effect of testicular capsulotomy on fertility of rats

Aim: To demonstrate the effect of capsulotomy on the fertility of male rats. Methods: Testicular capsulotomy was carried out in immature (21 days) and adult (60 days) male rats. The fertility of them was assessed by cohabitation with proestrus females overnight and 20 days later, the females were examined for impregnation. Morphological changes at the site of the capsulotomy were observed under light microscope. Results: In rats capsulotomized at Day 60, the fertility was gradually depressed and all the rats completely lost their fertility 2 months post - operation. At that time, a partial regeneration of the capsule at the site of capsulotomy was observed. Immature rats capsulotomized at Day 21 were found to possess normal fertility at maturity. The capsulotomy site was almost completely recovered 60 days post-operation. Conclusion: In male rats, testicular capsulotomy at the age of Day 60 will damage fertility. However, when capsulotomy is performed at Day 21. fertility is preserve.     

Obstruction of the tubuli recti and ductuli efferentes by dilated veins in the testes of men with varicocele and its possible role in causing atrophy of the seminiferous tubules

Hormone measurements, spermiograms and testicular biopsies studies were performed in young with varicocele. In addition, the testes and epididymides of 27 adults with varicocele were obtained from autopsies. Light and electron microscopic examination of biopsy and autopsy specimens revealed two types of lesions in testes with varicocele: 1) a diffuse lesion consisting of abnormal spermatozoa and spermatid morphology and sloughing of immature spermatozoa and spermatid; 2) focal lesion, distributed irregularly throughout the testicular parenchyma, affecting several small groups of seminiferous tubules. Each of these groups corresponded to a testicular lobule and showed different degrees of tubular atrophy, so that the focal lesions were distributed in a mosaic pattern. The testicular interstitium showed dilated veins and venules, and progressive collagenization. Some testes showed dilated veins in the rete testis, which compressed several tubuli recti and caused tubular atrophy in the seminiferous tubules opening into these tubuli recti. Other testes showed dilated young veins among the ductuli efferentes, and the rete testis channels appeared to be dilated. Among the different etiological mechanisms which have been suggested to for testicular lesions in varicocele, tubular obstruction at the level of either the tubuli recti or the ductuli efferentes might be responsible for lesions leading to testicular atrophy.     

神经肽Y在大鼠睾丸内的表达及其意义

目的 :分析神经肽Y(NPY)在大鼠睾丸中的表达 ,探讨NPY在雄激素生成和精子发生中的作用。　方法 :用RT PCR半定量法分析SD雄性大鼠睾丸中的NPYmRNA的表达 ,以β actin为内参照。用免疫组化法观察NPY在组织和细胞内的分布。　结果 :NPY基因在大鼠睾丸中有相当水平的表达 ,在PCR产物电泳图谱中见到明显的基因扩增产物条带 ;免疫组化显示 ,NPY在睾丸间质区、睾丸小血管周围及其精曲小管周围阳性表达 ,而在精曲小管内未见表达。　结论 :睾丸内表达的NPY可能直接参与了睾丸功能的调节。     

Distribution of carcinoma-in-situ in testes from infertile men

Quantitative histologial studies on 4 testes removed because of carcinoma-in-situ (CIS) were performed in order to determine the distribution of CIS within the testis and to estimate the likelihood of diagnosing testicular CIS by biopsy. The CIS changes were distributed in all parts of the testes but were less frequent in the parts adjacent to the epididymis. In the 4 testes examined 1.4 to 599 of the entire testicular volume contained seminiferous tubules with CIS. In parts of the testes where more than approximately 10% of the testicular volume consisted of tubules with CIS all simulated biopsies measuring 3 mm contained the lesion. The same was true for simulated biopsies measuring 1.5 mm when more then approximately 30% of the testicular volume consisted of tubules with CIS.
If the distribution of CIS generally is similar to that found in the 4 analysed testes there seems to be a high probability of detecting the disease by one or two testicular biopsies.     

On the Postnatal Development of the Terminal Segment of the Seminiferous Tubules in Normal and Germ Cell Depleted Rat Testes

The development of the terminal segment of the seminiferous tubules was studied in 5 to 50 days old normal rats. At the age of 5, 10, and 15 days the terminal segment contained fewer gonocytes or spermatogonia than did the corresponding seminiferous tubule. The differentiation of the terminal segment was obvious at 20 days of age due to the high number of germ cells in the seminiferous tubules, where the epithelium became stratified at this stage. The blood-testis barrier in the terminal segment was chiefly established between 15 and 20 days of age as revealed by the lanthanum tracer technique.
To study the effect of the germ cells on the differentiation, the germ cell depleted testes of prenatally irradiated rats were also studied. The modified Sertoli cells of the terminal segment were more vacoulated and had fewer lipid droplets and inter-Sertoli cell junctions than did the Sertoli cells of the seminiferous tubules. The ultrastructure of the modified Sertoli cells of the terminal segment was similar in adult normal and adult SCO (Sertoli cell only) rats. The amount of lipid droplets in the Sertoli cells of SCO rats showed considerable variation among different tubular cross-sections within one testis.     

Apoptosis and proliferation in human undescended testes

OBJECTIVE: To study apoptosis and proliferation in the testes of children with undescended testes; the degree to which undescended testes contributes to a patient's ultimate fertility is debatable, but undescended testes have fewer germ cells, and some have proposed that apoptosis is an important cause. PATIENTS AND METHODS: Testis biopsies were taken at the time of orchidopexy in a consecutive series of children undergoing surgical repair for undescended testes. Immunohistological techniques were used to detect apoptosis and proliferation, and the numbers of cells undergoing apoptosis or proliferation per 50 seminiferous tubules were recorded. RESULTS: Inguinal testes had less apoptosis than abdominal testes, with a mean (sd) of 0.71 (1.31) vs 1.63 (1.95) apoptotic cells per 50 seminiferous tubules (P < 0.02). Similarly, there was less apoptosis in children aged > 1 years than in children aged < 1 years (0.68 (1.40) vs 1.35 (1.56); P < 0.03). Proliferation was very limited in all cryptorchid testes. In contrast to cryptorchid testes, five autopsy controls had many more apoptotic cells, (10.60 (1.34) per 50 seminiferous tubules), and many more proliferating cells, (8.40 (6.43) per 50 seminiferous tubules). CONCLUSION: In contrast to animal studies, neither apoptosis nor proliferation was common in undescended testes from 6 months of age onward. However, apoptosis was more common in abdominal testes and in children aged < 1 year. It is likely that, if substantial apoptosis occurs in human undescended testes, it occurs before 6 months of age.     

先天性双侧输精管缺如患者睾丸超微结构的改变

目的 了解先天性双侧输精管缺如（Congenital bilateral absence of vas deferens,CBAVD)患者睾丸超微结构的改变,以预测单精子卵胞浆内注射（ICSI）治疗效果。方法 对13例光镜下睾丸组织形态学正常的CBAVD患者睾丸组织进行电镜观察。结果 曲细精管界膜改变表现变睾丸曲细精管基膜增厚,分层,向管腔形成不同程度的指状突起,基膜外胶原纤维呈不同程度增多,增粗、排列紊乱,极性消失,生精上皮表现为精子细胞头部畸形,胞核染色质呈现明显颗粒状结构。出现核内空泡,精子细胞中段线粒体鞘部分或完全缺失,顶体内陷,顶体囊增大,内有电子密度不高的片层结构（5例）。支持细胞表现数目增多,胞浆内脂质颗粒及降解小体明显增多。有时可见支持细胞之间的紧密连接消失（2例）。结论 CBAVD患者睾丸组织超微结构异常主要表现为界膜与精子细胞的改变,CBAVD所致的无精子症除了梗阻因素外,同时合并了睾丸性因素。     

Testicular biopsy in patients with obstructive azoospermia

The present report studies the testicular biopsy lesions (histologic and semiquantitative) in a series of 48 patients with obstructive azoospermia of known etiology (vasectomy, congenital absence of vas deferens, herniorrhaphy, hydrocelectomy, Young's syndrome, and ejaculatory duct obstruction) in order to establish objective testicular data that permit the pathologist to diagnose an obstructive process, which should not be mistaken with a primary testicular lesion. The semiquantitative study included determinations of the average numbers of spermatogonia, primary spermatocytes, young spermatids (Sa + Sb), and differentiated spermatids (Sc + Sd). According to this study, the testes were classified into the following groups: (1) normal testes whose germ cell numbers were within normal limits (27 testes); (2) testes with lesions in the adluminal compartment; these lesions comprise two subgroups: (2a) late sloughing of primary spermatocytes (both spermatid types were greatly reduced in number while the other germ cell types were in normal numbers) (45 testes); and (2b) early sloughing of primary spermatocytes (normal spermatogonial number, reduced number of spermatocytes, and scanty spermatids) (9 testes); and (3) lesions in the basal compartment; these lesions comprise two subgroups: (3a) pure hypospermatogenesis (a proportionate decrease in the numbers of all germ cell types) (8 testes); and (3b) hypospermatogenesis associated with sloughing of primary spermatocytes (decreased numbers of all germ cell types with a very scanty number spermatids) (4 testes). Two testes appeared hyalinized and one testis was removed owing to cryptorchidism. The most frequent testicular lesion observed (alteration in the adluminal compartment of seminiferous tubules) seems to be related to the increase in hydrostatic pressure in the tight compartment formed by seminiferous tubules, rete testis, efferent ducts, the epididymal duct, and the initial portion of the vas deferens. The severity of the lesions is probably related to the cause and span of the obstruction. In addition, two azoospermic men without obstructive azoospermia and whose testicular biopsy study revealed meiotic anomalies (with the subsequent bad prognosis) were also studied for comparison. The semiquantitative study of these patients permitted the differential diagnosis between two lesion types. Testes with meiotic anomalies had a disproportionately elevated number of primary spermatocytes, and an extremely low number of young spermatids.     

Relative Positions of the Spermatogenic Stages in the Mouse Testis: Morphological Evidences for their Non-Randomized Adjacencies

The topographical distribution pattern of the stages of the murine seminiferous epithelium cycle was investigated. PAS-hematoxylin stained testicular sections from adult mice representative of the apical, equatorial and caudal region of both testes, were used. The relative frequencies (RF) of the stages of the seminiferous epithelium cycle was estimated on the basis of more than 10,000 cross-sectioned seminiferous tubules identified according to the criteria of Leblond and Clermont (1952). It was found that in the testicular sections the stages of adjacent seminiferous tubules are not distributed randomly. The comparison of the RF of the stages (calculated over all the testicular sections) with the RF of the stages that are adjacent to a given seminiferous tubule stage suggests a clustered occurrence of numerically identical stages. These comparisons very often show statistically significant differences. The finding of such associations among adjacent segments of seminiferous tubules (stages) suggest the existence of an ordered distribution of the seminiferous tubules inside the testis possibly controlled by substances with local control capacity of spermatogenesis. On the basis of the findings here presented, it is suggested an interpretation of the phenomenon of modulations of the waves of the seminiferous epithelium.     

Testicular lymphangiectasis in Noonan's syndrome

We describe a boy with testicular lymphangiectasis and Noonan's syndrome. Both testes showed seminiferous tubules with a reduced tubular diameter, containing few spermatogonia. The testicular interstitium exhibited a number of large, dilated lymphatic vessels forming irregular channels among the seminiferous tubules and surrounding them. Since there was no accompanying pathological condition to indicate an obstruction to the lymphatic flow at the level of the spermatic cord or in the regional lymph nodes, the abnormal development of testicular lymphatic vessels suggests a congenital malformation.     

Histopathology of testis in acquired immune deficiency syndrome

Histologic sections from the testes of 32 autopsied patients with acquired immune deficiency syndrome (AIDS) were examined. Almost invariably the testes displayed decreased spermatogenesis, and 20 of the 32 cases showed marked hypospermatogenesis with Sertoli cells predominantly lining the tubules. Although the seminiferous tubules were generally of normal size, the tunica propria at the periphery of the tubules was mildly to moderately thickened in 19 cases and markedly thickened in 10. The interstitial cells of Leydig were unaltered in most patients, with only 4 testes showing Leydig cell hyperplasia. The testicular blood vessels were slightly thickened in many patients, but 5 exhibited moderate to marked intimal proliferation with narrowing of the lumen. Mononuclear inflammatory infiltration of the testicular interstitium was slight in 11 cases, moderate in 6. Only 7 of the 28 AIDS patients with opportunistic infections had evidence of direct involvement of the testes by the infectious organisms. We concluded that the extragonadal endocrine balance of AIDS patients may be deranged due to the infectious process and so deserves clinical evaluation.     

Pattern of Sertoli cell degeneration in cryptorchid prepubertal tests

Seventy-three testicular biopsies from 54 children (aged 2 months-14 years) with undescended testes were examined by light and electron microscopy. The biopsies included abdominal, inguinally fixed, inguinally moveable, and retractile testes. Alterations in Sertoli cell morphology were found in all biopsies. The alterations included dilated elements of rough endoplasmic reticulum, vacuolization of the cytoplasm, mitochondria with poorly preserved cristae, increase in electron density of the matrix, elongation of the nuclei, and irregularities of the nuclear membrane. According to the numerical appearance of these cells and to the extent of lesions in single Sertoli cells, seven phases in the continuous process of tubular alteration were distinguished. The most severe tubular damaged (phase VII) occurred when the seminiferous epithelium consisted exclusively of necrotic cells. All phases of tubular alterations were seen regularly in each of the biopsies investigated. Germ cells occurred only in phases I-IV and were never observed in tubules in phases V-VII. Significant differences became evident between inguinal and retractile testes by morphometric evaluation. It was demonstrated that the number of germ cells per cross-sectioned tubule (S/T value) correlated negatively with the percentage of tubules in phases V-VII. In contrast to inguinal testes, a complete absence of Sertoli cells and an S/T value less than 0.1 were never found in retractile testes and the percentage of tubules in phases V-VII was reduced significantly compared with inguinal testes. Our findings indicate that (i) maldescended testis in patients between 1 and 15 years-of-age is associated with a special pattern of Sertoli cell degeneration; (ii) Sertoli cell degeneration is a continuous process, which can lead eventually to complete dissolution of the seminiferous epithelium; (iii) total degeneration is not related to age but is dependent on testicular position; (iv) a defined phase of degeneration excludes germ cell development, and therefore enhanced Sertoli cell degeneration in cryptorchid testes must also account for the reduction in germ cell number.     

Melatonin prevents testicular damage in hyperlipidaemic mice

The damaging effect of hyperlipidaemia on testicular structure was determined, and the influence of melatonin was evaluated in testicular damage related to hyperlipidaemia. Hyperlipidaemia was induced in ApoE-knockout C57BL/6J male mice fed with high-fat diet alone (group A), or with high-fat diet and melatonin (group B). Six ApoE wild-type C57BL/6J male mice were fed with normal diet, served as controls. At the end of the experimental period, ultrastructural observations showed dramatically histopathological alterations in testicular tissues of group A. The basement membranes of seminiferous tubules were partially thickened and wavy-like in testes of mice with hyperlipidaemia, and vacuolar degeneration of mitochondria and dilation of endoplasmic reticulum were identified as well as the number of mitochondria and lipid droplets decreased significantly in Leydig cells and Sertoli cells. Electrondense deposits were observed in cytoplasms of germ cells. The testicular histostructure in group B treated with melatonin was similar to that of control. Apoptosis was determined by terminal-deoxynucleotidyl-transferase-mediated dUTP nick end labelling. Apoptotic germ cells were significantly more numerous in group A than in group B and controls. The results suggest that melatonin may be potential to attenuate testicular damage by improving histopathological changes and reducing germ cell apoptosis in hyperlipidaemic mice.     

Histopathological mapping of open testicular biopsies in patients with unobstructive azoospermia.

OBJECTIVE: To evaluate, in patients with unobstructive azoospermia, the heterogeneity of spermatogenesis within the testes and thus whether there is any region of advanced spermatogenesis. Patients and methods Seventy infertile men (mean age 34 years, SD 5.01) with no varicoceles or testicular atrophy had bilateral open testicular biopsies taken from six different sites. For each biopsy specimen the number of seminiferous tubules and of tubules with sperm maturation were counted (by light microscopy at x 400). The ratio of tubules with active spermatogenesis to the total number was calculated for each biopsy sample. RESULTS: The mean (SD) right and left testicular volumes were 19.82 (7.8) and 18.84 (7.89) mL, respectively; the patients' follicle-stimulating hormone level was 8.34 (1.17) IU/mL. On sextant biopsy spermatozoa were detected in 42 of the 70 patients (60%). The mean (SD) ratio of tubules with spermatozoa was 5.23 (0.8)% for the right and 5.37 (0.76)% for the left testes. There was no statistically significant difference in the ratio of seminiferous tubules positive for spermatozoa at the different biopsy sites in either the right or left testis. Spermatozoa were identified in only one to three biopsy sites in almost half of those with maturation arrest; this ratio increased to 74% in patients diagnosed as having Sertoli-cell-only syndrome with focal spermatogenesis. Conclusion There is no region of the testis that is rich or advanced in spermatogenesis in patients with unobstructive azoospermia. Without multiple testicular biopsy it is possible to miss advanced spermatogenesis in some unobstructed patients. The sextant testis biopsy is a reliable method for detecting the presence and exact location of seminiferous tubules with spermatozoa in patients with unobstructive azoospermia.