Testicular Development in the Unilaterally Cryptorchid Rat

By cutting the distal part of gubernaculum testis in newborn rats cryptorchism was produced. This new method to obtain cryptorchid animals has the advange of preventing testicular descent before it normally takes place, thus mimicking congenital cryptorchism. Unilaterally cryptorchid rats were examined at 20, 30 and 100 days of age. Morphometric methods were used to compare the structure of the abdominal and the scrotal testicles during development. In the abdominal testicles some tubular cells were damaged already at 20 days of age, i. e. when the temperature difference between the testicles probably is quite small.
In the abdominal testicles the pathological changes of the tubules precede those of the interstitium. The descended testicles of unilaterally cryptorchid rats were identical to testicles of normal control rats, and all the operated rats were fertile at adult age.     

单侧隐睾大鼠生殖股神经在对侧睾丸损害中的作用机制研究

目的 :探讨单侧隐睾大鼠模型生殖股神经在对侧睾丸损害中的作用机制。　方法 :建立单侧隐睾大鼠模型 (2 1d龄 ) ,切断该侧生殖股神经 ,12 0d后观察对侧睾丸的生精细胞凋亡变化及组织乳酸含量变化。　结果 :切断生殖股神经后 ,对侧睾丸生精细胞凋亡为 (5 .76± 0 .76 ) % ,与对照组 (17.2 8± 1.36 ) %相比明显减少 (P <0 .0 5 ) ;乳酸含量也由 (2 .19± 0 .2 4 )mmol/L下降为 (1.70± 0 .31)mmol/L(P <0 .0 5 ) ,且乳酸含量与细胞凋亡呈正相关(P <0 .0 5 )。　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     

Multi-Vacuolated Leydig Cells in Human Adult Cryptorchid Testes

A histological study of 23 testicular biopsies or surgical specimens from adult cryptorchid testes revealed the presence of multi-vacuolated Leydig cells in 12 cases. These cells showed abundant lipid inclusions and scarce secondary lysosomes as well as liprofuchsin pigment granules. Some of these cells contained crystals of Reinke but others had only microcristalline inclusions. This Leydig cell alteration may be related either to heat or to congenital lesions.     

Morphometric and Functional Investigation on the Leydig Cells in Experimental Unilateral Cryptorchism in the Rat

By distal gubernaculotomy on one side in newborn rats testicular descent was prevented on that side, and unilateral cryptorchid rats were obtained. Leydig cell structure and function was studied at 20, 30 and 100 days of age, using both morphometric and biochemical techniques. Up to 30 days of age no differences in structure of the interstitium and Leydig cells, or testicular testosterone concentration were observed between the scrotal and the abdominal testicles. In contrast the tubular cells in the abdominal testicle were highly damaged already at 30 days of age. The abdominal testicles of the 100-day-old rats contained the same total number of Leydig cells as the scrotal testicles, but the size of these cells, and the testicular testosterone concentration were highly reduced. Thus Leydig cell function in the cryptorchid testicle was maintained at 30 days but highly impaired at 100 days of age. Tubular damage occurred prior to the Leydig cell malfunction.     

环氧合酶-2在成年雄性大鼠睾丸和附睾中的表达

目的:探讨环氧合酶 2在雄性大鼠睾丸和附睾组织中的表达及其意义。　方法:应用免疫组化SP法检测 40只雄性SD大鼠睾丸和附睾组织中环氧合酶 2的表达及其定位情况。　结果:环氧合酶 2在雄性大鼠的睾丸和 附睾组织中有较强的表达。在附睾头部主要表达于腔上皮细胞的细胞核内,部分细胞质内也可见表达,睾丸精原 细胞胞质和细胞核内均可见棕黄色颗粒。　结论:免疫组化法可较为敏感地检测环氧合酶 2在雄性大鼠睾丸和 附睾组织的表达。     

Malignant Degeneration in Cryptorchid Testes A Report of Two Cases

In two patients with cryptorchism orchidectomy was performed because of testicular atrophy and torsion respectively. From the macroscopic appearance malignancy was not expected in either of the cases, but histological examination showed invasive carcinoma. This indicates that biopsies should be taken whenever operations are performed on cryptorchid testes, and it may be of importance to biopt all cryptorchid testes at a certain age.     

Reversible effect of testosterone undecanoate injection on spermatogenesis in rats

Aim: To study the effect of testosterone undecanoate (TU) injection on spermatogenesis in rats. Methods: Twenty adult SD rats received vehicle or TU (8 mg/kg, 19 mg/kg or 025 mg/kg) injection, im, every 15 days for days, and another 38 animals received similar treatments for 130 days with half of them undergoing a recovery phase of 120 days (5 rats for each treatment). At the end of the treatment, testes were removed and the diameter of the seminiferous tubules and the number of late elongated spermatids ( steps 15 - 19 ) per testis were estimated with stereological methods as a measure of the spermatogenic efficiency. Results: Low dose (8 mg/kg) TU treatment virtually had no effect on spermatogenesis. A dose of 19 mg/kg slightly suppressed spermatogenesis 60 days after treatment, and severe suppression occurred after another 70 days of dosing. Spermatogenesis was completely recovered at the end of the recovery phase. Large dose (625 mg/kg) TU treatment did not significantly affect spermatogenesis and was well tolerated by animals. Conclusion: TU injection reversibly suppresses spermatogenesis in rats.     

Effect of Thyroidectomy and Adrenalectomy on the Physio-chemical Status of Rat Testes

Influence of thyroid and adrenal hormones on the testicular biochemical activities and their role in the mechanism of male gonadal function were scantily reported. The present study in the thyroidectomized and adrenalectomized animals revealed that thyroid deficiency caused decrease in acid phosphatase activities, increase in cholesterol and GOT activities, where as hypoadrenalism had to some extent opposite effects compared to intact controls.
These findings point out that thyroid hormones are very important for and regulate the male reproduction by maintaining the gonadal biochemical homeostasis and adjuvating the action of gonadotrophins for steroidogenesis.
Der Einfluß von Thyreoidektomie und Adrenalektomie auf den physiologischen Status des Rattenhodens

Zusammenfassung

Über den Einfluß von Schilddrüsen- und Nebennierenhormonen auf die biochemischen Prozesse und ihre Wirkung auf die männliche Gonadenfunktion wird ausführlich berichtet.
Die vorliegende Arbeit an thyreoidektomierten und adrenalektomierten Tieren zeigt, daß eine Unterfunktion der Schilddrüse einen Abfall der sauren Phosphatase, den Anstieg von Cholesterin und GOT bewirkt. Eine Unterfunktion der Nebenniere hingegen wies gegenüber gesunden Kontrolltieren in einem gewissen Ausmaß entgegengesetzte Befunde auf. Diese Ergebnisse zeigen, daß die Schilddrüsenhormone für die Regulation der männlichen Fortpflanzung bedeutsam sind, indem sie die biochemische Homoiostase der Gonaden aufrechterhalten und die Wirkung der Gonadotropine auf die Steroidsynthese unterstützen.     

Quantitative （stereological） study of incomplete spermatogenic suppression induced by testosterone undecanoate injection in rats

Aim: To evaluate the key lesions in spermatogenesis suppressed partially by testosterone undecanoate(TU) treatment. Methods: Adult male SD rats were treated with vehicle or TU (19 mg/kg) injection (i.m.) every 15 days for 130 days. The numbers of all types of cells (nuclei) in the seminiferous tubules and the interstitial tissue were estimated using a contemporary stereological tool, the optical disector. Results: In response to TU treatment, the numbers of non-type B spermatogonia, type B sperrnatogonia and late elongated spermatids per testis were reduced to 51%, 66% and 14% of the controls, respectively. The conversion ratios from type B spermatogonia to early spermatocytes and pachytene spermatocytes were not significantly affected and the ratios to the later germ cell types fell to 51%-65% of the controls. Less than 1.0 % of immature round spermatids were seen sloughing into the tubule lumen, 4.0% of elongated spermatids retained in the seminiferous epithelium, and about half of the elongated spermatid nuclei appreciably malformed. Leydig cells were atrophied but their number and the peritubular myoid cell number per testis were unchanged. Conclusion: Double inhibition of spermatogenesis (i.e. inhibition at spermiation and spermatogonial conversion to type B spermatogonia), a scenario seen in the monkey and human following gonadotrophin withdrawal, was not sufficiently effective for a complete spermatogenic suppression in the rat after TU treatment, probably due to ineffective inhibition of the Leydig cell population and therefore the intra-testicular test-osterone levels. (Asian J Androl 2004 Dec; 6: 291-297)     

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。     

Hormonal Milieu of the Seminiferous Tubules in the Normal and Cryptorchid Rat

The intratesticular concentration of androgens seems to be of more importance for normal spermatogenesis than the concentration of androgens in the peripheral blood.
Therefore, the levels of testosterone, 5α - dihydrotestosterone (DHT), androstenedione and FSH in the interstitial fluid of the rat testis were determined by radioimmunoassay. The following concentrations were obtained from the interstitial fluid of normal rats and from rats cryptorchid between 60 and 90 days of age: Testosterone 137 ± 25 (mean ± SEM) and 271 ± 34 ng/ml, DHT 11 ± 2 and 22 ± 5 ng/ml, androstenedione 8 ± 2 and 20 ± 4 ng/ml, respectively. The sum of testosterone and DHT in serum did not differ in the two groups. Serum FSH concentrations were significantly increased in the cryptorchid rats (942 ± 73 ng/ml) as compared to the control rats (600 ± 38 ng/ml). These elevated levels were also found in the testicular interstitial fluid (425 ± 33 ng/ml in controls, 641 ± 43 ng/ml in cryptorchid rats). It is thus evident that in the cryptorchid rat, both FSH and androgens are available to the seminiferouse tubules in significantly elevated amounts. Since these are the only hormones which are known to be of importance in spermatogenesis, the impaired Sertoli cell function and depletion of germinal cells in cryptorchidism is not due to an absolute shortage of stimulatory hormones.     

Fine Structure of the Sertoli Cells of the Rat Testis in Experimental Unilateral Cryptorchidism

Mature rats were made unilaterally cryptorchid for 28 days. ABP concentrations of the abdominal epididymis were significantly reduced, indicating impaired secretory activity of the Sertoli cells.
The FSH serum level was increased and testosterone levels both of the serum and of homogenates of the cryptorchid testis were slightly reduced. Sertoli cells of the cryptorchid testis showed signs of regression. Although Sertoli cell junctions were still impermeable to lanthanum, a reduction of membrane particles forming the Sertoli cell junctions was observed in freeze-fracture replicas. In thin sections it was seen that the plasma membrane-apposed cisternae of endoplasmic reticulum or the adjaacent microfilaments were partially lacking. No such changes were observed in the scrotal testis.     

Histopathological Changes in Testes of Adult Inbred Rats Immunized Against Pachytene Spermatocytes or Sertoli Cells

Adult inbred Lewis/Wistar rats, immunized against pachytene spermatocytes or Sertoli cells prepared from maturing rats of the same strain, develop histopathological changes in the testes comparable in several respects to those reported by others in classical experimental allergic orchitis. Early changes in the structure of pachytene spermatocytes are followed by germ cell degeneration, and defoliation of germinal cells into the lumen. Concomitantly, abnormalities develop in Sertoli cell structure, and the lymph-testis barrier becomes increasingly permeable. Sertoli cells are the only testicular somatic cells which appear to be directly sensitive during the immunologic response. Disturbances in Sertoli cell functions are postulated to be crucial in the etiology of aspermatogenesis. The data are discussed in relation to the possible roles in spermatogenesis of specific antigenic determinants present on the surfaces of mature Sertoli cells and advanced germinal cells located within the adluminal compartment of the seminiferous tubule.     

Electron Microscopic Study of Interstitial Cells in Cryptorchid Human Testes. I: Interstitial Cells in Prepubertal Age

In order to establish the ultrastructural features of Leydig cells 50 biopsies or prepubertal human cryptorchid testes have been examined. Light and electron microscopic observations reveal the presence of two types of interstitial cells distinguishable on the basis of the peculiar ultrastructural characteristic of the nucleus and cytoplasm. In our opinion these two types of interstitial cells seem to represent different stages of cell differentiation. There are fibroblast-like cells and cells corresponding to Leydig cells. From our observations it may be inferred that the fibroblast-like cells are the precursor cells of the Leydig cells.     

Serum testosterone response to single injection of hCG ovine-LH and LHRH in male rats

A biphasic pattern of testosterone secretion in response to a single injection of 100 IU hCG has been observed in the rat. Serum testosterone increased from basal levels of 8.7 pL 3.1 ng/ml (mean pL SEM) to 23.0 pL 1.4 ng/ml within 2 h of hCG-stimulation and returned to control levels by 2 days. A second, delayed, but significant increase in serum testosterone occurred, reaching a peak of 24.6 pL 4.0 ng/ml at 3 days and declining to basal values at 5 days. To study this response further, lower doses of hCG were tried. Administration of 10 IU hCG produced a single peak of testosterone, which did not occur until 24 h. Differences in the serum testosterone response were related to the concentration of hCG measured in the serum after injection, as injection of 1 IU, which failed to increase serum hCG levels above detection, was also inadequate to increase serum testosterone. The response after stimulatin with 500 μg ovine-LH or 0.1–10.0 μg LHRH was also evaluated. Injection of 500 μg ovine-LH produced a significant rise in serum testosterone reaching a peak at 2 h of 25.2 pL 2.6 ng/ml and subsequently declining over the next 48 h to control levels where it remained for 5 days. Stimulation with doses of 0.1–10.0 μg LHRH produced rapid and short increases in serum LH concentration which induced peaks of testosterone up to 48.8 pL 14.1 ng/ml 1 h post injection. No secondary peak of testosterone followed. Failure of ovine-LH and LHRH to produce a second testosterone peak suggests that this response may be due to a re-stimulation of the Leydig cell by elevated levels of hCG which persist until the fourth day after injection.     

Testosterone Levels in the Male Laboratory Rat: Variation under Experimental Conditions

This report describes the variation of testosterone (T) levels in male Wistar rats (250–300 g) bled under typical laboratory conditions. Plasma T in 114 rats ranged from 2–48 nmol/l (median 13.1: 95% confidence range, 10–15) and varied significantly ( P < 0.01) during the day (07.30-16.30 h) with an acrophase between 09.00 h and 13.00 h. The distribution of plasma T levels was skewed ( P < 0.05) and could be divided into basal values > 26 nmol/l and peaks > 26 nmol/l. Testosterone in testicular tissue and testis veins also varied during the day and was lower ( P ≤ 0.02) between 14.30 h and 16.30 h than from 11.30-13.30 h. It was shown that plasma T may differ significantly ( P ≤ 0.02) between groups (n = 6–7) of untreated rats bled under identical conditions and it is suggested that gonadotrophin stimulation be included in experimental designs to reduce the difficulty of differentiating between normal variability and treatment effects.     

邻苯二甲酸二丁酯对大鼠睾丸生化酶及脂质过氧化的影响

目的 :探讨邻苯二甲酸二丁酯 (DBP)对睾丸生化酶及脂质过氧化的影响 ,为接触人群早期诊断及生物学监测提供参考评价指标。　方法 :选择 6周龄雄性SD大鼠随机分成 4组 ,每组 16只。灌胃给予DBP ,剂量为 0 (对照组 )、2 5 0、5 0 0、10 0 0mg/ (kg·d)。于染毒 2周和 4周末分别处死 8只大鼠 ,收集睾丸及其他脏器和血清 ,以 1∶3的比例制备睾丸匀浆。测定血清和睾丸匀浆中生化酶及谷胱甘肽过氧化物酶 (GSHPx)的活性和谷胱甘肽 (GSH)的含量。　结果 :随DBP染毒剂量的增加 ,肝脏器系数明显上升 ,而睾丸脏器系数显著下降 (P <0 .0 1)。染毒 2周后 ,血清中GSHPx活性和睾丸匀浆中GSH水平下降趋势明显 ,而匀浆中GSHPx活性呈上升趋势 ,10 0 0mg/ (kg·d) 组与对照组相比 ,差异有显著性 (P <0 .0 5 )。染毒 4周后 ,血清中碱性磷酸酶活性呈上升趋势 ,血清和睾丸匀浆中山梨醇脱氢酶 (SDH )活性受到明显抑制 ,10 0 0mg/ (kg·d) 组与对照组相比差异均有显著性 (P <0 .0 1)。血清GSH水平呈上升趋势 ,10 0 0mg/ (kg·d) 组与对照组比较差异有显著性 (P <0 .0 5 )。　结论 :DBP可对机体产生明显的毒性作用 ,主要靶器官为肝脏和睾丸。脂质过氧化可能是DBP毒性作用的机制之一 ,SDH是DBP对睾丸毒性作用较为敏感的指标之一。     

实验性精索静脉曲张对大鼠同侧睾丸的影响

目的:利用大鼠动物模型来研究实验性精索静脉曲张(EV)对其同侧睾丸的影响。方法:EV模型的制作是通过在雄性SD大鼠左侧精索内静脉和肾上腺静脉内侧部分结扎左肾静脉。60只雄性青春期SD大鼠随机分为EV持续6、12、18周组(EV6、EV12、EV18组,每组12只)和相应的接受假手术的对照组(每组8只)。于6、12、18周,摘取成功复制成EV模型大鼠(分别为10,8,9只)以及各自接受假手术的对照组大鼠左侧睾丸,检测其Johnsen's评分、生精小管超微结构、睾丸组织睾酮浓度(ITC)和生精细胞的凋亡指数(AI)。结果:EV6、EV12、EV18组Johnsen's评分(6.92±0.52,4.83±0.41,2.95±0.26)和ITC(6.32±0.85,5.17±0.76,4.11±0.69)均显著低于各自对照组[(9.56±0.35,9.63±0.31,9.39±0.46)和(9.64±1.23,9.38±0.69,9.73±0.49)](P<0.05),并且随着精索静脉曲张持续时间的增加而逐渐降低;EV6、EV12、EV18组AI(5.32±1.23,15.21±0.97,21.13±1.12)显著高于各自对照组(3.21±1.15,3.43±1.21,3.61±1.15),并且随着精索静脉曲张持续时间的增加而逐渐升高;各EV组生精小管的超微结构损伤也随着精索静脉曲张持续时间的增加而逐渐严重。结论:EV导致同侧睾丸ITC下降、生精功能的进行性损害、生精细胞AI增加。     

Effect of Prostaglandins A-1, E-2 and F-2a on Blood Plasma Levels of Testosterone, LH and FSH in Male Rats

Effects of the administration of PGs A-1, E-2 and F-2 alpha (150 micrograms/rat b.i.d. for 10 days) were studied. Significant increase in testicular weight was observed only in PGE-2 treated group. Testicular ascorbic acid content reduced significantly by treatment with all the PGs. PGE-2 treatment caused a significant decrease in the content of testicular cholesterol, while no change was observed in the same and prostatic acid phosphatase activity in any of the PG treated groups. Blood plasma levels of testosterone drastically reduced by both PGE-2 and PGF-2 alpha, while there was no change in the levels of plasma LH in any of the groups. Plasma FSH levels increased significantly in PGA-1 treated rats only. The results suggest that 1) There is a direct action of PG particularly PGE-2 on testicular weight. PGE-2 increases testicular weight possibly by preventing degeneration of spermatids, 2) PGE-2 acting directly on the testis, reduces testicular ascorbic acid content, stimulates the conversion of cholesterol to pregnenolone but depresses the conversion of the latter to testosterone.