Secondary changes in the scrotal testis in experimental unilateral cryptorchidism

Unilateral cryptorchidism was induced in under 2-day-old Wistar rat pups. A control group of rats underwent sham operation at the same age. The animals were killed at intervals from 5 to 120 days, both testes were excised, weighted, and processed for histological examination, morphometric measurement of the seminiferous tubules, and DNA flow cytometry. There was no difference in weight, Johnsen score, and tubular size between the scrotal testis of cryptorchid animals and control testes at any age. Significant decreases in all of these parameters occurred in the undescended testis from 30 days when compared with the scrotal testis in cryptorchid animals and controls. Using flow cytometry to measure changes in the DNA ploidy of the cells of the seminiferous epithelium during spermatogenesis, a significant decrease in the haploid population of cells occurred in the scrotal testis of cryptorchid animals at 40 days. This difference continued into adult life (P less than .005). Flow cytometry demonstrates a secondary decrease in spermatogenesis in the scrotal testis in experimental unilateral cryptorchidism.     

Studies on the scrotal testis in unilateral experimental cryptorchidism in rat and guinea pig

The effects of experimental unilateral cryptorchidism on the scrotal testis regarding weight, morphology and secretion of tubular fluid and the sertoli-cell specific androgen binding protein (ABP) were studied. In the intact guinea pig testis and epididymis an androgen binding component similar to rat ABP was found. In juvenile and adult rats cryptorchid for 17 and 21 days, respectively, and in guinea pigs cryptorchid for 11 weeks, the scrotal testis seemed unaffected regarding all parameters studied. With reference to previous findings of lowered fertility in unilateral cryptorchidism in man the possible mechanisms by which unilateral cryptorchidism may influence the scrotal testis are discussed.     

Reversal of degenerative changes in the scrotal testis after orchidopexy in experimental unilateral cryptorchidism.

Unilateral cryptorchidism was induced in newborn Wistar rat pups. Using DNA flow cytometry to compare scrotal testes of control and cryptorchid animals, there was a significant difference decrease in the haploid cell population in cryptorchid animals from 40 days of age. Orchidopexy was performed at 30 days (at the time of normal descent), 50 days (pubertal), and 90 days (fully mature adult). When with sham-operated control and cryptorchid animals of the same age were compared, there was no decrease in the haploid population at any age in the scrotal testis if orchidopexy was performed at 30 days; the degenerative changes could be reversed to normal if orchidopexy was performed at 50 days; however, if operation was delayed to 90 days, the decreased numbers of haploid cells in the scrotal testis were neither prevented nor reversed and remained significantly lower than normal controls (P less than .005). This study shows that orchidopexy performed before adulthood reverses secondary degenerative changes in the scrotal testis in an animal model of unilateral cryptorchidism.     

A new experimental model for cryptorchidism: inguinoscrotal approach

We investigated the effect of inguinal canal closure as a new mechanically induced cryptorchid rat model. The effectiveness of this new model was evaluated by histopathological examination. Thirty-one 21-day-old Wistar rats were divided into four groups. In groups 1 (n=6), 2 (n=6) and 3 (n=7), unilateral undescended testis was created by performing inguinal canal closure with inguinoscrotal approach. Sham-operated rats were used as controls in group 4 (n=12). The rats were killed on day 30 after surgery in group 1, day 45 in group 2 and day 60 in group 3. The seminiferous tubular diameter, number of tubules with mature germ cell and Leydig cell clusters were evaluated. None of the rats were lost during the study period. Signs of infection were not detected in operation site although antibiotics were not used. Overall only three (16%) testes descended into scrotum in study groups. The operation time was 3–4 min for each rat. Histopathological examination revealed detrimental effects of cryptorchidism on testicular growth in study groups. In all groups, except the sham group, the mean tubular diameter and the number of tubules with mature germ cells in the left testicle were significantly decreased compared to the right ones. Our findings were in correlation with other experimental studies using different rat models of cryptorchidism. This new model of cryptorchidism is considered to provide a simple and effective technique for investigating the impaired development of the testes in cryptorchidism. Received: 26 September 2000 / Accepted: 27 December 2000     

单侧隐睾大鼠对侧睾丸的损害与Bcl-2和Bax基因表达

目的:探讨单侧隐睾大鼠对侧睾丸生精细胞凋亡与Bcl-2/Bax基因表达的关系。方法:20只健康SD雄性大鼠(22日龄)随机分成隐睾组和对照组,每组10只。通过手术建立单侧隐睾动物模型。术后90 d取对侧睾丸,采用原位缺口末端标记(TUNEL)法检测生精细胞凋亡,免疫组化SP法检测Bcl-2/Bax基因表达。结果:与对照组相比,隐睾组对侧睾丸生精细胞凋亡显著增多(P<0.01),重量显著减轻(P<0.01),Bax表达显著升高(P<0.01),Bcl-2表达显著降低(P<0.01)。凋亡细胞主要是初级精母细胞和圆形精子细胞。结论:单侧隐睾大鼠对侧睾丸的生精细胞凋亡增多与Bcl-2基因表达降低、Bax基因表达升高密切相关。细胞内Bc l-2/Bax比值是影响生精细胞凋亡的重要因素之一。     

FasL在大鼠隐睾中的表达

目的 :观察FasL蛋白在大鼠隐睾中的表达并探讨其意义。　方法 :将 2 2日龄SD雄性大鼠 2 4只随机分为隐睾组和假手术组各 1 2只 ,在日龄 1 1 0d时采血并处死。免疫组化 (SP法 )测睾丸组织中的FasL蛋白表达 ,ELISA法检测血清抗精子抗体 (AsAb)。　结果 :隐睾组大鼠的隐睾侧及对侧睾丸的FasL阳性表达率均显著高于假手术组大鼠的手术侧及对侧睾丸 (P <0 .0 0 1 ) ;隐睾组和假手术组的血清AsAb阳性率分别为 41 .7%和 0 ,差异有显著性 (P <0 .0 1 )。　结论 :单侧隐睾大鼠的双侧睾丸组织中都有FasL表达的上调 ,可能是睾丸对自身免疫的一种保护性反应     

Assessment of germ cell apoptosis in cryptorchid rats

Aim: To investigate the relationship between germ cell degeneration and apoptosis in cryptorchid rats. Methods: Thirteen 21-day-old Wistar rats were made unilaterally cryptorchid by closing the left inguinal canal. At day 30 (Group 1, n=6) and day 60 (Group 2, n=7) after operation, the testes were removed for histopathological examination. The controls (n=8) were sham operated and were sacrificed at day 60. Germ cell apoptosis was assessed by means of the TUNEL method. Results: Spermatogenesis was arrested and the testicular and seminiferous tubular diameters were significantly reduced In the unilateral undescended testes (UUTs) compared with the contralateral descended testes (CDTs) and the control rats. However, atrophic changes, pathological calcification, necrosis of seminiferous tubule, and absence or sloughing of germ cells were not found in all the animals. The spermatocytes were the main type of germ cells undergoing apoptosis in all the groups. In the UUTs, there was a significant and time-depe     

生殖股神经在单侧隐睾鼠对侧睾丸损害中的作用机制

目的：探讨生殖股神经在单侧隐睾鼠模型对侧睾丸损害中的作用机制。方法：建立单侧隐睾鼠模型（21d龄），切断该侧生殖股神经，120d后观察对侧睾丸的生精细胞凋亡及细胞乳酸含量变化。结果：切断生殖股神经后对侧睾丸生精细胞凋亡减少，乳酸含量降低，乳酸含量与细胞凋亡呈正相关。结论：单侧隐睾症对侧睾丸损伤可能与其神经传导反射性血流减少引起生精细胞凋亡有关。     

Effect of cryptorchidism on testicular and Leydig cell androgen production in the mouse

Unilateral cryptorchidism was induced surgically in adult mice and the effects on testicular and Leydig cell steroidogenesis were studied after 7 weeks. There was a 60% reduction in weight of the cryptorchid testis and this was associated with a significant reduction in intratesticular androgen content, both under basal conditions and following an injection of hCG. Testicular androgen production in vitro was also significantly lower in the cryptorchid testis compared to the scrotal testis, again under both basal conditions (29 +/- 6% of control) and in the presence of hCG (46 +/- 9% of control). Scrotal testes from the unilaterally cryptorchid animals did not show any significant difference in steroidogenic capacity compared to testes from untreated control animals. The decrease in steroidogenic capacity of the cryptorchid testis was due, at least in part, to a reduction in activity for each Leydig cell. In four experiments, androgen production by Leydig cells isolated from cryptorchid testes was 48 +/- 9% of cells from scrotal testes in the presence of a saturating dose of hCG. Under basal conditions the effect was more variable between experiments with steroid secretion by Leydig cells from cryptorchid testes being 58 +/- 32% of that for cells from scrotal testes. Leydig cell steroidogenesis in the scrotal testes of unilaterally cryptorchid animals did not differ significantly from untreated controls. These results show that induced cryptorchidism in the mouse causes a significant reduction in Leydig cell activity. This is apparently different from the effects of this procedure on the rat and raises the possibility that intratesticular regulation differs between the two species.     

Effect of kolaviron,a biflavonoid complex from Garcinia kola seeds,on the antioxidant,hormonal and spermatogenic indices of diabetic male rats

The antihyperglycaemic effect of kolaviron (KV), a biflavonoid from Garcinia kola has been established in previous studies. In this study, we investigated the effect of KV (200 mg kg^?1) on the antioxidant, hormonal and spermatogenic indices of alloxan‐diabetic male rats, and metformin hydrochloride (MET) (30 mg kg^?1) served as standard drug. The results showed that KV and MET significantly (P < 0.05) decreased the fasting blood glucose of the diabetic rats. Also, untreated and MET‐treated diabetic groups had significantly (P < 0.05) lower body‐weight gain and relative weights of testes. In addition, epididymal sperm abnormalities were increased, whereas sperm count, motility, testicular protein and sialic acid were decreased in untreated diabetic group. Also, antioxidant parameters, reduced glutathione, catalase, superoxide dismutase, glutathione‐S‐transferase and glutathione peroxidase were significantly (P < 0.05) reduced in the testes with a concomitant increase in lipid peroxidation in untreated diabetic group. Furthermore, untreated diabetic group had significantly (P < 0.05) lower levels of testosterone, luteinising and follicle‐stimulating hormones relative to controls. Treatment with KV restored the relative weights of testes, activities of antioxidant enzymes, sperm and hormonal indices of the diabetic animals. This study demonstrated the role of KV to promote fertility in diabetic male rats by enhancing the hormonal and antioxidant status of the rats.     

Acquired cryptorchidism is frequent in infancy and childhood

Accurate prevalence data for acquired cryptorchidism are currently sparse and systematic prospective studies have not yet been reported. Our aim was to determine the prevalence of testicular ascent in childhood. In a prospective longitudinal population-based child cohort from Copenhagen, Denmark (1997–2007), testicular position was examined according to a standardised protocol in a total of 1072 boys, at birth ( n  = 1051), at 3 months ( n  = 983), 18 months ( n  = 888), 36 months ( n  = 790) and again once between 4½ and 10 years of age ( n  = 509). Ascensus testis was defined as ascent of the testis into a cryptorchid position after normal scrotal position at birth. A congenital cryptorchid testis with spontaneous postnatal descent followed by recurrence of cryptorchidism was named recurrent cryptorchidism. Ascensus testis occurred in 0.2%, 0.6% and 0.6% of boys at 3, 18 and 36 months of age respectively. When including recurrent cryptorchidism the prevalence was 0.2%, 1.2% and 0.8% respectively. Ascensus testis accounts for 58% of all cases of cryptorchidism (congenital and acquired) at 18 months, 71% at 36 months and thereafter 69%. Ascensus testis accounts for more than half of cryptorchid testes seen in childhood and occurs in both previously scrotal and cryptorchid testes. We therefore recommend that all boys should have testis position checked regularly during childhood, at least up to 3 years of age.     

Study on antisperm autoimmunity in experimental cryptorchid rats

Study on antisperm autoimmunity in experimental cryptorchid rats     

大鼠单侧隐睾对侧睾丸的损害与抗氧化酶mRNA的表达

目的　从基因表达水平探讨单侧隐睾对侧睾丸损害机制。方法　 3 0只SD雄性大鼠分为对照组与隐睾组 ,每组各 15只。采用逆转录 聚合酶链反应 (RT PCR)方法检测对侧睾丸中谷胱甘肽过氧化物酶 (GSH PX)、铜 /锌超氧化物岐化酶 (Cu/Zn SOD)、过氧化氢酶 (CAT)mRNA的表达 ;化学比色法测定丙二醛 (MDA)的含量 ;生物素 dUTP/酶标亲和素法检测睾丸生殖细胞的凋亡。结果　术后 2周 ,与对照组比较 ,隐睾组GSH PX和SODmRNA表达明显下降 ,MDA和生殖细胞凋亡明显升高 (P <0 .0 1) ,而CATmRNA表达无明显改变 (P >0 .0 5 )。结论　单侧隐睾对侧睾丸存在GSH PX和SODmRNA表达降低 ,氧自由基升高和生殖细胞过度凋亡。     

Early signs of Sertoli and Leydig cell dysfunction in the abdominal testes of immature unilaterally cryptorchid rats

Testicular descent was prevented unilaterally by cutting the gubernaculum testis of newborn rats. When 20 days old unilaterally cryptorchid rats were injected intraperitoneally with 2 μg bFSH per gram body weight and killed 6 h later when testicular testosterone (T) and oestradiol (E₂) concentrations were determined. The increase in E₂ was subnormal in abdominal testes. In 18-day-old unilaterally cryptorchid rats the efferent ducts were ligated bilaterally, and the rats were killed 48 h later. The weight increase, due to accumulation of seminiferous tubule fluid, was significantly greater in the abdominal testes. In contrast, the ABP content of the abdominal epididymis was subnormal in 20-day-old unilaterally cryptorchid rats. Unilateral orchidectomy was performed in 16-day-old unilaterally cryptorchid rats and at 20 days of age intratesticular T and E₂, and plasma FSH and LH concentrations were determined and compared to that in 20-day-old control unilaterally cryptorchid rats. Removal of an abdominal testis resulted in increased plasma FSH and intratesticular E₂, whereas plasma levels of LH and intratesticular levels of T were unaffected. Removal of a scrotal testis resulted in increased plasma FSH and LH coupled with increased intratesticular T and E₂. Rats with a single abdominal testis had higher plasma FSH and LH and intratesticular T, but similar intratesticular E₂, than rats with a single scrotal testis. It is concluded that Sertoli and Leydig cell function are influenced by cryptorchidism at a stage when the temperature difference, and the morphological differences between the testes are very discrete.     

Impaired estrogen production by Leydig cells of the naturally retained testis in unilaterally cryptorchid boars and stallions

Estrogen production in vitro was compared for Leydig cells from cryptorchid and scrotal testes in boars and stallions. Animals with natural and experimental cryptorchidism were used. Purified Leydig cells were prepared from testes of mature animals by collagenase treatment and Percoll density gradients. After incubation for 3 hours (1 X 10(6) cells), estrone sulfate and estrone in the media were measured by direct radioimmunoassay. Androstenedione and testosterone in media extracts also were determined. Cells from the abdominal testis of unilateral cryptorchid boars and stallions showed impaired estrogen production compared with that of the contralateral scrotal testis. Surgical translocation of the scrotal testis to the abdominal cavity in four unilaterally cryptorchid, prepubertal boars did not result in a reduced capacity for estrogen secretion by Leydig cells examined after puberty. Cells from the naturally retained testis in each of these four animals produced practically no estrogen. In a naturally bilateral cryptorchid stallion, there was a high rate of estrogen secretion by both testes. It was concluded that the scrotal testis of a unilaterally cryptorchid animal exerts a suppressive influence on estrogen formation by the abdominal testis.     

Endocrine Effects of Early Non-Union of Testis and Epididymis and of Cryptorchidism in the Rat/Endokrine Effekte bei jungen Ratten nach experimenteller Trennung von Hoden und Nebenhoden wie auch nach experimentellem Kryptorchismus

The aim of this study was to explore possible endocrine effects of early non-union of testis and epididymis. In 16 days old Sprague-Dawley rats the testis and epididymis were separated to the level of the inferior epididymis artery (non-union operation). Animals were killed at intervals from 30-58 days, and the plasma concentrations of total testosterone, total estrogens, LH, FSH and PRL were measured. The testes were studied by light microscopy. Groups of rats made cryptorchid and sham-operated rats were used as controls. Although their testes were scrotal, the non-union operated animals had testosterone and estrogen concentrations similar of cryptorchid animals, and significantly (p less than 0.05) lower than sham-operated animals. The LH- and FSH-concentrations were significantly (p less than 0.05) elevated suggesting a primary lesion in both Leydig- and Sertoli-cells. Towards puberty FSH increased in the non-union operated animals, while FSH values declined in the cryptorchid and sham-operated animals. These FSH-patterns probably reflect the existence of different pathogenic mechanisms in the non-union operated rats and the rats with cryptorchid testes.     

Ghrelin is a suppressor of testicular damage following experimentally induced cryptorchidism in the rat

Background

Cryptorchidism is associated with increased level of reactive oxygen species and lipid peroxidation. This study was undertaken to examine the possible ghrelin ability in attenuation of testicular damage in response to elevated temperature.

Methods

Thirty male rats were subdivided into sham-operated, cryptorchidism-saline and cryptorchidism-ghrelin group. Bilateral cryptorchidism was induced in groups 2 and 3, surgically. The animals in group 3 were given ghrelin for 7 days and all testes were taken for biochemical and photomicrograph analysis.

Results

Glutathione peroxidase activity and glutathione content significantly promoted on day 7 in the cryptorchid rats treated by ghrelin. Catalase activity was higher in the ghrelin-exposed animals than the cryptorchidism-saline group on both experimental days. Although superoxide dismutase activity was elevated by ghrelin treatment on both days, it did not differ significantly. By contrast, significant reduction was observed in thiobarbituric acid reactive substances concentrations following ghrelin administration on day 7. Moreover, ghrelin could improve histopathological scores of the testes, and diminished formation of giant cells and tubular vacuolization.

Conclusions

These findings indicate for the first time the novel evidence of ghrelin antioxidant properties in attenuation of rat testicular injury following experimentally induced cryptorchidism.     

血管内皮细胞生长因子和内皮型一氧化氮合酶在大鼠单侧隐睾对侧睾丸损害中的表达

目的 探讨大鼠隐睾中内皮型一氧化氮合酶(eNOS)和血管内皮细胞生长因子(VEGF)的表达与单侧隐睾对侧睾丸损害的关系.方法 将45只雄性SD大鼠(22 日龄)随机分成单侧隐睾并生殖股神经离断组(A组)、单侧隐睾组(B组)和假手术组(C组),每组15只.动物模型建立后(65日龄),苏木素-伊红(HE)染色观察睾丸生精上皮形态,原位缺口末端标记法(TUNEL)检测对侧睾丸生精细胞的凋亡,免疫组织化学和Western blot方法检测对侧睾丸组织中eNOS和VEGF基因表达的变化.结果 B组相对于A组和C组对侧睾丸组织中生精细胞的凋亡率最高(t1=3.04,t2=3.94,t1,t2＞t28,P＜0.01),Western blot和免疫组织化学方法检测结果也显示B组eNOS和VEGF的表达含量较A组和C组都显著升高,差异有统计学意义(P＜0.01),而A组和C组的各指标差异均无统计学意义(P＞0.05).结论 eNOS和VEGF的高表达和生殖股神经在单侧隐睾对侧睾丸的损害中起重要作用,而切断生殖股神经可以阻断这一损害过程.

Abstract：

Objective To study the relationship between the expression of endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) with the damage of contralateral testis of unilateral cryptorchidism in the experimental rats. Methods Forty-five immature male Sprague-Dawley rats (aged 22 days) were randomly divided into the group A (unilateral cryptorchidism and the ipsilateral genitofemoral nerve division), group B (unilateral cryptorchidism), group C (sham operation), n = 15 in each group. When the rats were aged 65 days, all the rats were sacrificed and the testes were obtained. The morphological changes of the spermatogenic epithelium in the testes were observed, and the germ cell apoptosis was detected by the TdT-mediated dUTP-biotin nick end labeling (TUNEL) technique. The expression of eNOS and VEGF was detected by using Western blotting and immunohistochemistry in the testicular tissues.Results The germ cell apoptosis was increased significantly ( t1 = 3. 04, t2 = 3. 94, t1 ,t2 ＞ t28 , P ＜0. 01) , and the levels of eNOS and VEGF in the contralateral testes were also increased obviously in group B as compared with groups A and C ( P ＜ 0. 01) , but the entire indexes in groups A and C had no significant difference. Conclusion eNOS, VEGF and genitofemoral nerve play a important role in the damage of the contralateral testes of unilateral cryptorchidism, and the damage can be prevented by genitofemoral nerve division.     

Effect of epidermal growth factor on spermatogenesis in the cryptorchid rat

PURPOSE: Epidermal growth factor (EGF) is secreted mainly from the submandibular glands. Submandibular gland ablation causes a marked decrease in male fertility, which suggests that EGF influences spermatogenesis. We investigated the effect of EGF in combination with orchiopexy on cryptorchid rat testes in which tubular deterioration had become partially irreversible. MATERIALS AND METHODS: Unilaterally cryptorchid rats were obtained by daily administration of 7.5 mg flutamide (Nihonkayaku, Tokyo, Japan), an androgen receptor antagonist, to pregnant rats. At age 10 weeks the unilaterally cryptorchid rats underwent orchiopexy with or without EGF administered into the cryptorchid testis. EGF solution (10 microg/ml) was delivered into the seminiferous tubules by retrograde perfusion through the rete testis. At 14 days testicular recovery was assessed based on the maturity of spermatogenesis using a modified Johnsen score and from the number of apoptotic germ cells per seminiferous tubule. RESULTS: Mean Johnsen score +/- SEM was significantly higher in the orchiopexy with EGF than in the orchiopexy without EGF group (7.85 +/- 0.12 vs 7.12 +/- 0.13, p <0.001). The number of apoptotic germ cells tended to be smaller in the orchiopexy with EGF group than in the orchiopexy without EGF group (0.16 +/- 0.05 vs 0.28 +/- 0.08). CONCLUSIONS: Although orchiopexy for cryptorchidism partly improved spermatogenesis, recovery was limited. EGF administered in combination with orchiopexy was more effective for spermatogenesis than orchiopexy alone. This may be applicable in patients with cryptorchidism.     

Laminin, type IV collagen, and fibronectin in normal and cryptorchid human testes. An immunohistochemical study

An immunohistochemical study of laminin, type IV collagen, and fibronectin was carried out in the testes of normal men and in the cryptorchid and contralateral scrotal testes of cryptorchid men from 2 to 40 years of age. The integrated optical density (IOD) per unit area of the lamina propria was measured in the immunostained sections. Fibronectin was found throughout the thickness of the lamina propria of the seminiferous tubules and in the interstitial connective tissue. No differences between normal and cryptorchid testes were found. Laminin was observed in the innermost part of the lamina propria of the seminiferous tubules and surrounding the endothelium of blood capillaries from infancy. No differences were found between normal and cryptorchid testes in the prepubertal period. In adult cryptorchid testes, laminin formed more numerous and deeper invaginations towards the seminiferous epithelium than in normal adult testes. Type IV collagen appeared throughout the thickness of the lamina propria of normal testes as well as in the wall of interstitial blood vessels. From infancy, the lamina propria of seminiferous tubules, but not blood vessel walls, showed lesser immunostaining for type IV collagen and a lower IOD of this component than did control tests from men of the same age. No differences between unilateral and bilateral cryptorchidism were found. The contralateral scrotal testes of cryptorchid males showed intermediate immunostaining for type IV collagen between that of normal control testes and that of cryptorchid testes. These findings suggest that the lamina propria of seminiferous tubules is lesioned at an early age in both cryptorchid and contralateral scrotal testes of cryptorchid men.