Testicular steroid sulfatase in a cryptorchid rat strain

Steroid sulfatase (STS) activity was studied in scrotal and abdominal testes from genetically unilateral cryptorchid rats. Specific STS activity was significantly increased in microsomes from abdominal and scrotal testes of the cryptorchid animals as compared to that of control ones. When expressed per gonad, STS activity was only enhanced in the scrotal testis. No difference in the enzyme affinity was observed between descended and undescended testes. Testosterone content was markedly reduced in the abdominal testes. Normal plasma testosterone levels together with elevated LH levels were measured in the cryptorchid rats. The existence of differences in STS expression between descended and undescended testes gives additional support for this enzymatic activity being implicated in testicular function.     

Maldescendus testis

Maldescendus testis is a common congenital abnormality occurring in 2-5% of full-term boys at birth in the Western countries. By 3 months of age, the incidence rate spontaneously reduces to 1-2% in this group. The etiology of the disorder is not known, but normal hypothalamo-pituitary-gonadal axis is usually a prerequisite for normal descent of the testes. Abnormal sexual differentiation is associated with maldescent. However, the majority of boys with maldescended testes show no endocrine abnormalities after birth. Several defects in developmental genes, such as homeobox genes and Insl3, have been described to cause cryptorchidism in mice, and disturbances in the regulation of these genes or their mutations may explain etiology of a large part of human testicular maldescent in the future. Increased degeneration of germ cells can be observed in undescended testes after the first year, and therefore early treatment is recommended. Surgical treatment is the most effective and reliable method to bring testes into the scrotum, but hormone treatment with either hCG or GnRH analogues can be considered, particularly in cases where testes can be palpated in high scrotal position. The efficacy of hormone treatment is less than 20% and depends on the initial location of the testis. Nonpalpable testes rarely descend with hormone treatment. Both surgery and hormone treatment can have untoward effects. Treatment with hCG has been associated with an inflammation-like reaction in the testes and an increased rate of apoptosis of germ cells leading to a reduced adult size of the testes. Vascular complications can occur during surgery, particularly in staged orchidopexies. Men with a history of undescended testis have an increased risk of testicular cancer. Impaired fertility is another long-term risk associated to maldescended testes. Fertility potential may be improved by early treatment. Although our knowledge on cryptorchidism has increased considerably during the last decades, many questions remain to be answered: Is the incidence rate increasing? What is causing maldescent? Do hormones have any role in the treatment?     

Morphologic study of the testes from spontaneous unilateral and bilateral abdominal cryptorchid boars

Macroscopical and histological characteristics were examined in both testes from three healthy boars, three boars with unilateral abdominal cryptorchidism on the right side, and three boars with bilateral abdominal cryptorchidism. Abdominal cryptorchidism, unilateral and bilateral, provoked a significant decrease of the weight and volume of the ectopic testes. The scrotal testis of the unilateral cryptorchid boars showed an increase in its volume and weight. Cryptorchidism also induced abnormalities in the histological structure of seminiferous tubules, lamina propria, and interstitial tissue of the abdominal testes. The number of seminiferous tubules decreased; the seminiferous epithelium was constituted by few spermatogonia with an atypical pattern and by abnormal Sertoli cells. The lamina propria showed a variable degree of thickening and collagenization. The interstitial tissue was very developed but displayed a decrease in the Leydig cell population. These abnormalities were more critical in bilateral cryptorchidism than in unilateral cryptorchidism. The scrotal testis of the unilateral cryptorchid boars showed normal appearance, but a decrease of the number of seminiferous tubules was observed. Moreover, the seminiferous tubules showed impaired spermatid maturation. The alterations observed in the abdominal testes of the unilateral and bilateral cryptorchid boars were attributed to defective proliferation and differentiation of Sertoli cells and Leydig cells. The anomalies in the scrotal testis of the unilateral cryptorchid boars were due to disturbances in the Sertoli cell activity.     

Cryptorchidie et température testiculaire

The testis migrates to a scrotal location before birth. This physiological descent is associated with a reduction in the temperature of the testicular environment since the temperature of the scrotal cavity is lower than that of the body one. This leads to the etablishment of a themperature gradient between the testis and the body which already exists in prepubertal boys. In cases of testicular maldescent (cryptorchidism), the temperature of the testis in its cryptorchid location is much higher than that of the normally descended contrlateral testis. However, there are no data obtained from human studies to establish wether the increased temperature of a cryptorchid testis is responsible for the spermatogenic perturbations typically observed. Nor do we know wether the relocation of a cryptorchid testis to the scrotum permits re-establishment of a normal testicular temperature. Adult men with a history of cryptorchidism constitute about 10% of infertile men, and among these previously cryptorchid infertile men 45% have an abnormally elevated scrotal temperature. This abnormal increase in scrotal temperature is a negative risk factor for fertility: these men have smaller testicular volumes, a more severely impaired spermatogenesis and a higher prevalence of primary infertility than previously cryptorchid infertile than previously cryptorchid infertile men with normal scrotal temperature. However, data provided until now do not allow to know whether elevated temperature is due to the decreased testicular size (hypotrophy) or is a consequence of cryptorchidism per se.     

Efficiency of the process of meiosis in scrotal testes of healthy boars and unilateral abdominal cryptorchid boars.

Unilateral abdominal cryptorchidism has usually been correlated with abnormalities in the spermatogenic activity of the scrotal testis. The present study describes the effects of unilateral abdominal cryptorchidism on the meiotic process in scrotal testes from postpubertal boars. The percentage of primary spermatocytes, secondary spermatocytes, and round spermatids was evaluated in testicular smears from scrotal testes of healthy boars and of right-sided unilateral abdominal cryptorchid boars. As compared to the scrotal testes of healthy boars, the scrotal testes of unilateral abdominal cryptorchid boars showed low transformation from primary to secondary spermatocytes (meiosis I), but normal transformation from secondary spermatocytes to round spermatids (meiosis II). The data obtained indicate that spontaneous unilateral abdominal cryptorchidism on the right side induced partial arrest of spermatogenesis at the primary spermatocyte stage that was attributed to anomalies in Sertoli-cell activity. Abnormal paracrine signals from altered Sertoli cells could have resulted in either disturbed mitosis, which led to the formation of spermatocytes with an abnormal DNA content, or abnormalities in the metabolic activity and the organization of the cytoskeleton of primary spermatocytes.     

Androgen secretion and characteristics of testicular HCG binding in cryptorchid rats

Response of the cryptorchid testis to gonadotrophic stimulation was assessed by comparison of the androgen production capability in vivo and in vitro with that of the normal scrotal testis. Serum androgen concentrations in cryptorchid rats were similar to those in normal rats, and the incremental increase 60 min after 50 i.u. hCG (i.v.) was about 7-fold for both groups. Basal and hCG-stimulated androgen production in vitro was higher for abdominal testes (557 and 3286 ng/pair) than for scrotal tests (157 and 504 ng/pair). Specific binding of hCG by testicular homogenates was slightly higher (P < 0.05) for cryptorchid testes when expressed per unit weight, but Scatchard analysis indicated that although hCG binding affinities did not differ (Ka = 2 x 10(10) M-1), hCG binding capacity of cryptorchid testes was only 75 ng, compared to 219 ng for scrotal testes. These data indicate that a discrepancy exists between androgen production in vivo and in vitro by cryptorchid testes and that normal serum androgen concentrations are maintained in the presence of decreased numbers of testicular LH/hCG receptors.     

Abnormal zinc metabolism in unilateral maldescended testes of a mutant rat strain

The status of zinc in a mutant rat strain with heritable maldescended testes was examined. In rats with unilateral maldescended testis, the ectopic testis consistently had decreased zinc content (121.0 +/- 23.0 micrograms zinc/g dry wt), while the eutopic testis had zinc content similar to that of normal rats (182.0 +/- 5.0 micrograms zinc/g dry wt). Uptake of zinc by the ectopic testis was comparable to normal. Sephadex gel chromatography showed greatly reduced zinc content of one of the endogenous zinc binding fractions with a mol wt of 30,000 of cytosol of the ectopic testis in spite of a near normal protein content. Incorporation of zinc-65 into this fraction was also shown to be greatly reduced in ectopic testis. Sodium dodecylsulphate-polyacrylamide gel electrophoresis demonstrated that a protein of 23,000 Da was greatly reduced in quantity. This 23-kDa protein in ectopic testis may play a role in reduced testicular function of the ectopic testis.     

Differences in aromatase activity between Leydig cells from the scrotal and abdominal testis in the naturally unilateral-cryptorchid boar

In an earlier study, estrogen production was much lower in Leydig cells from the abdominal than from the scrotal testis in naturally occurring unilateral cryptorchidism in the boar. A more direct assessment of aromatase activity was made in thirty-two mature male pigs to examine this observation further, using nonradioactive androstenedione (delta 4A 1.0 x 10(-6) M - 1.5 x 10(-5) M) and [1 beta, 2 beta-3H] delta 4A as substrates. Purified Leydig cells were prepared from normal boars and from unilaterally and bilaterally cryptorchid animals. Combined estrone sulfate (E1S) and estrone (E1) formation from delta 4A were measured by radioimmunoassay. Little or no estrogen secretion was seen with cells from the abdominal testis in unilaterally cryptorchid boars (n = 7), and E1S formation from delta 4A was 6- to 14-fold higher for scrotal cells (n = 6). Aromatase activity as reflected in percent conversion of substrate to [3H]-labeled water was clearly lower in cells from the abdominal testis (1.10 +/- 0.08 and 11.22 +/- 0.7%, respectively, p less than 0.01, n = 6). No marked reduction was noted for unilaterally cryptorchid boars with an inguinally located testis (10.18 +/- 0.27 and 13.09 +/- 0.58% for inguinal and scrotal testes, respectively, n = 3). Concentrations of E1S in testicular arterial and venous blood (n = 9) gave additional evidence of lower estrogen production by the undescended testis of the cryptorchid boar. It was concluded that lower aromatase activity is present in Leydig cells of the abdominal testis.     

Abnormal germ cell development in cryptorchidism.

BACKGROUND: Previous studies suggest that two fundamental, probably androgen-dependent, steps in maturation of germ cells normally occur in the prepubertal testis: the disappearance of gonocytes (the fetal stem cell pool) and the appearance of adult dark spermatogonia (the adult stem cell pool) at 2-3 months of age and the appearance of primary spermatocytes (the onset of meiosis) at 4-5 years. Previous studies of small series of cryptorchid boys suggest that both steps are defective in undescended testes and to a lesser degree in descended testes contralateral to unilaterally undescended testes. The purpose of this study is to confirm the previous findings of defective germ cell maturation in a large series of boys with unilateral undescended testes. PATIENTS: Seven hundred and sixty-seven boys with unilateral cryptorchidism who had orchidopexy and bilateral testicular biopsies between birth and 9 years of age were studied. MATERIALS AND METHODS: Total and differential germ cell counts were performed on semithin histologic sections of the biopsies. The results from the undescended and contralateral descended testes were compared using the Wilcoxon signed-rank test and the Wilcoxon-Whitney-Mann U test. RESULTS: Gonocytes failed to disappear and adult dark spermatogonia failed to appear in undescended testes under 1 year of age indicating a defect in the first step in maturation at 2-3 months resulting in failure to establish an adequate adult stem cell pool. Primary spermatocytes failed to appear in undescended testes and appeared in only 19% of contralateral descended testes at 4-5 years of age indicating a defect in the onset of meiosis. CONCLUSION: Unilaterally undescended testes fail to establish an adequate adult stem cell pool which normally occurs at 2-3 months of age and fail to establish adequate meiosis which normally occurs at 4-5 years of age. Similar but less severe changes are seen in the contralateral descended testes. Defects in the two pubertal steps in germ cell maturation are associated with reduced total germ cell counts.     

Cytology of the interstitial tissue in scrotal and abdominal testes of post-puberal boars

The interstitial tissue of the testes from healthy boars, and unilateral and bilateral abdominal cryptorchid boars was examined by light and transmission electron microscopy. The left and right testes of healthy boars, and the left (scrotal) testis of unilateral cryptorchid boars had abundant mature Leydig cells, few fibroblasts and mast cells, scarce and small blood vessels, and little lymphatic areas. The right (abdominal) testis of unilateral cryptorchid boars contained abundant Leydig cells, fibroblasts and erythrocytes, scarce mast cells, and frequent blood vessels; Leydig cells exhibited either a mature but degenerative appearance or an immature appearance, and fibroblasts displayed immaturity signs. The interstitial tissue of the left (abdominal) testes of bilateral cryptorchid boars had small blood vessels surrounded by erythrocytes, lymphocytes, and few plasma cells, and abundant mature and immature Leydig cells, immature fibroblasts, and mast cells. Mature Leydig cells showed mid or advanced degeneration, and immature Leydig cells displayed either non-degenerative or degenerative patterns. The right (abdominal) testes of bilateral cryptorchid boars contained scarce immature Leydig cells in advanced degeneration, large fibrous and adipose areas, and blood vessels. These results indicated that unilateral abdominal cryptorchidism affect neither the structural nor the cytologic features of the interstitial tissue in scrotal testes. Unilateral and bilateral cryptorchidism induced abnormal differentiation of Leydig cells and fibroblasts leading to decreased steroid production and increased collagenization in abdominal testes.     

Clinical, morphological and endocrinological aspects of cryptorchidism in the horse

The authors analysed clinical, histological and hormonal data obtained from 205 cryptorchid horses. The majority of the unilaterally and bilaterally retained testes were located in the inguinal canal; however, the ratio of inguinal vs abdominal retention appeared to decrease with advancing age. In unilateral cryptorchidism, a pronounced preference was noted for left abdominal retention, whereas for inguinal cryptorchids, the retained testes occurred equally on both sides. Right inguinal retention was found to decrease with advancing age. Histology of cryptorchid testes revealed apparently normal Leydig cells and arrested spermatogenesis. Plasma testosterone concentrations were similar in normal stallions and unilateral cryptorchids, even in those which had the scrotal testis removed. Plasma oestradiol-17beta levels were lower in unilateral cryptorchids than in stallions.     

Environmental effects on hormonal regulation of testicular descent

Regulation of testicular descent is hormonally regulated, but the reasons for maldescent remain unknown in most cases. The main regulatory hormones are Leydig cell-derived testosterone and insulin-like factor 3 (INSL3). Luteinizing hormone (LH) stimulates the secretion of these hormones, but the secretory responses to LH are different: INSL3 secretion increases slowly and may reflect the LH dependent differentiated status of Leydig cells, whereas testosterone response to LH is immediate. Testosterone contributes to the involution of the suspensory ligament and to the inguinoscrotal phase of the descent, while INSL3 acts mainly in transabdominal descent by stimulating the growth of the gubernaculum. INSL3 acts through a G-protein coupled receptor LGR8. In the absence of either INSL3 or LGR8 mice remain cryptorchid. In humans only few INSL3 mutations have been described, whereas LGR8 mutations may cause some cases of undescended testis. Similarly, androgen insensitivity or androgen deficiency can cause cryptorchidism. Estrogens have been shown to down regulate INSL3 and thereby cause maldescent. Thus, a reduced androgen–estrogen ratio may disturb testicular descent. Environmental effects changing the ratio can thereby influence cryptorchidism rate. Estrogens and anti-androgens cause cryptorchidism in experimental animals. In our cohort study we found higher LH/testosterone ratios in 3-month-old cryptorchid boys than in normal control boys, suggesting that cryptorchid testes are not cabable of normal hormone secretion without increased gonadotropin drive. This may be either the cause or consequence of cryptorchidism. Some phthalates act as anti-androgens and cause cryptorchidism in rodents. In our human material we found an association of a high phthalate exposure with a high LH/testosterone ratio. We hypothesize that an exposure to a mixture of chemicals with anti-androgenic or estrogenic properties (either their own activity or their effect on androgen–estrogen ratio) may be involved in cryptorchidism.     

Canine cryptorchism and subsequent testicular neoplasia: case-control study with epidemiologic update

A retrospective study of 2,912 cryptorchid dogs identified 14 breeds with significantly high risk. Among six distinct closely interrelated breed groups (e.g., toy, miniature, and standard poodles), the risk in the smaller breed was always greater than that in the larger relative, suggesting that genetically influenced maldescent could be, in part, related to physical size or the rate of growth of the involved structures. Testicular tumors were diagnosed in 5.7% of the cryptorchid dogs; half had only Sertoli cell tumors, one-third had only seminomas. The relative risk for Sertoli cell tumor or seminoma was not directly related to a familial risk for cryptorchism. Using the health experience of a control population composed of male dogs with anal sac disease (N = 4,184), there is an estimated relative risk of 9.2 in cryptorchid dogs to develop a testis tumor (95% confidence interval, 5.9-14.3) and 4.2 in dogs with inguinal hernia (95% confidence interval, 1.8-9.5). Considering that the anatomical development of the genital tract, testis descent, and tunic relationships in dog are very similar to that in man, and that the associations of cryptorchism and inguinal hernia with testis neoplasms are also similar, the dog should be an excellent model system to further investigate the causes of human cryptorchism.     

Hormonal treatment for unilateral inguinal testis: comparison of four different treatments.

BACKGROUND: Hormonal treatment of cryptorchidism has been used since the 30s, but controversies persist on its efficacy. It is also unclear whether there are differences with the use of different hormonal trials. Aims: To evaluate the efficacy of four hormonal treatments on testicular descent in a homogeneous group of cryptorchid boys. PATIENTS: 155 patients (age 10-48 months) with unilateral inguinal palpable testis were studied. Methods: The patients were subdivided into four groups according to hormonal treatment: group 1 = hCG [500 IU/week (if the chronological age was <2 years) or 1,000 IU/week (if the chronological age was >2 years) for 6 weeks]; group 2 = hCG + hMG (hCG as in group 1 + hMG 75 IU/week for 6 weeks); group 3 = GnRH (1,200 microg/daily for 28 days); group 4 = GnRH + hCG (1,200 microg/daily for 28 days + 1,500 IU/week for 3 weeks, respectively). The results were evaluated at the end of the treatment period and 6 months later to exclude temporarily positive results. RESULTS: At the end of the hormonal therapy, scrotal testicular descent was present in 30 of 155 boys (success rate 19.3%). Seven testes relapsed during follow-up (23.3%). The long-term success rate was 14.8% (23/155 testes). No significant differences were observed in success rates as well as in relapse rates among the four groups. CONCLUSIONS: Hormonal therapy induced permanent testicular descent in a minority of young cryptorchid boys with inguinal palpable testis. Similar results were obtained with four different trials.     

Regeneration of Leydig cells in unilaterally cryptorchid rats: evidence for stimulation by local testicular factors

Summary Leydig cells in testes of adult rats were selectively destroyed by a single intraperitoneal injection of ethane dimethane sulphonate. Four days later rats were made unilaterally cryptorchid and 1, 2 and 4 weeks later the histology of the testes was examined by light microscopy and morphometry. After induction of unilateral cryptorchidism, the volume of abdominal compared to scrotal testes was reduced by 45–60% due to rapid impairment of spermatogenesis in abdominal testes. Leydig cells were not present in either scrotal or abdominal testes in the 1-week unilateral crytorchid group. A new generation of foetal-type Leydig cells was observed in scrotal testes of the 2-week unilateral crytorchid group although their total volume per testis estimated by morphometry, was small, being approximately 1 l. In contrast, the abdominal testis exhibited a remarkable proliferation of foetal-type Leydig cells (total volume per testis, 16 l) which predominantly surrounded the peritubular tissues of the seminiferous tubules. A similar morphology and pattern of Leydig cell development was observed in scrotal and abdominal testes of the 4-week unilateral cryptorchid group where total Leydig cell volume was 7 l vs 21 l, respectively. The results show that regeneration of a new population of Leydig cells occurs more rapidly in the abdominal testis than in the scrotal testis of the same animal. These observations suggest the possibility that augmentation of Leydig cell growth is mediated by local intratesticular stimulatory factors within the abdominal testis. Development of new Leydig cells from the peritubular tissue provides circumstantial evidence that the seminiferous tubules and in particular the Sertoli cells, are a likely source of agents that stimulate the growth of Leydig cells.     

Effect of cryptorchidism on steroidogenic and mitogenic activities in rat testicular interstitial fluid

There was a significant (P less than 0.05) and consistent increase in the potency of steroidogenic stimulatory activity (testosterone production by purified Leydig cells in vitro) in testicular interstitial fluid of the cryptorchid compared to the scrotal testis from 1 to 4 weeks after the induction of unilateral cryptorchidism. In contrast, the level of mitogenic activity [( 3H]thymidine incorporation into 3T3 cells) was not significantly different between interstitial fluid from cryptorchid and scrotal testes for up to 4 weeks after surgery. These results indicate that the steroidogenic activity and the mitogenic activity are due to different, as yet unidentified, factors in testicular interstitial fluid.     

An anatomic and genetic study of canine cryptorchidism.

Twelve cases of cryptorchidism were found in a colony of Minature Schnauzer purebred and crossbred dogs. At least nine affected dogs were derived from the same sire directly or indirectly. Of 12 affected dogs, five cases were unilateral and seven were bilateral. Eight of the 12 cases were subjected to anatomic study. Fixation of affected organs was by vascular perfusion or immersion. Testes were separated from epididymides and both were weighed. All unilateral retained testicles were on the right side, and right sided bilaterally retained testes were always smaller than their left sided counterparts. With only one exception, ectopic testes were in the abdominal positon. Developmentally, the morphologic appearance of the epididymis of abdominal testes was very primitive in bilateral cases but nearly normal in the unilateral cases. Degree of inbreeding was greater for bilateral cases than unilateral cases. High incidence of cryptorchidism in this colony provided good evidence for hereditary nature of the condition in the Miniature Schnauzer dog. Morphologic observations were suggestive of a multiple gene defect.     

Treatment of cryptorchidism with human chorionic gonadotropin or gonadotropin releasing hormone. A double-blind controlled study of 243 boys

We have conducted a modified double-blind study on the effect of human chorionic gonadotropin (hCG), gonadotropin releasing hormone (GnRH) and placebo on bilateral and unilateral maldescended testes. One hundred and fifty-five boys with bilateral and 88 boys with unilateral cryptorchidism fulfilled the inclusion criteria and completed the treatment protocol. The boys were between 1 and 13 years of age. hCG was administered as intramuscular injections twice weekly for 3 weeks. GnRH and placebo were given intranasally. hCG was superior to GnRH and placebo in the treatment of bilateral maldescended testes (p = 0.0009). Both testes descended in 25% of the boys following treatment with hCG, and improvement in the position of the testes was obtained in a further 25% of the cases. hCG administration resulted in complete testicular descent in 14% of boys with unilateral cryptorchidism compared with 3 and 0% after placebo and GnRH, respectively (p = 0.07). The testis had moved to a more distal position in 46% of the boys treated with hCG. There was no significant difference between the treatment groups with regard to age or initial position of the testes. We conclude that a success rate of 25% justifies the use of hCG in the treatment of maldescended testes, whereas the study did not support a general use of GnRH administered intranasally.     

Risk of testicular cancer in cohort of boys with cryptorchidism.

OBJECTIVE: To determine the risk of testicular cancer in relation to undescended testis and its treatment based on recorded details of the maldescent, treatment, and biopsy from case notes. DESIGN: Cohort study. SETTING: Hospital for Sick Children, Great Ormond Street, London. SUBJECTS: 1075 boys with cryptorchidism treated by orchidopexy or hormones at the hospital during 1951-64. MAIN OUTCOME MEASURES: Relative risk of testicular cancer in the cohort compared with men in the general population. RESULTS: 12 testicular cancers occurred in 11 of the patients during follow up to mid-1990 (relative risk of cancer in males with cryptorchidism = 7.5 (95% confidence interval 3.9 to 12.8)). The relative risk fell significantly beyond 15 years after orchidopexy but did not decrease with younger age at orchidopexy. Risk was significantly raised in testes that had had biopsy samples removed during orchidopexy (relative risk = 66.7 (23.9 to 143.3) compared with a testis in a man in the general population) and was significantly greater in these testes than in undescended testes that had not had biopsy samples taken at orchidopexy (6.7 (2.7 to 13.5)). No reasons for biopsy or distinguishing clinical aspects of the testes that had had biopsy samples taken and later developed malignancies were evident in the case notes. No histological abnormalities were evident at initial biopsy except in one testis that had features of dysgenesis. CONCLUSIONS: Biopsy seems to be a stronger risk factor for testicular cancer than any factor previously identified. The trauma of open biopsy may contribute substantially to risk of malignancy or the testes may have been selected for biopsy on the basis of clinical factors predictive of malignancy but not mentioned in the case notes.