Scrotal Testes Research Articles

Degenerative Changes in Spermatogonia Are Associated with Loss of Glucose Transporter (Glut 3) in Abdominal Testis of Surgically Induced Unilateral Cryptorchidism in Rats

Expression of facilitative glucose transporters (Glut 1, 2 and 3) was examined by Western blot analyses 10, 20 and 30 days following surgically induced unilateral abdominal cryptorchidism. The cryptorchid testes exhibited marked degenerative changes in the seminiferous tubules and spermatogonia, impaired and incomplete spermatogenesis and lack of spermatozoa in the lumen. Immunoblotting of testis proteins with Glut transporter antibodies revealed only the presence of Glut 2 and 3 protiens. Glut 2 expression in abdominal testis was increased (45%, 67%, and 40% at 10, 20 and 30 days, respectively) but no significant change was observed in contralateral scrotal testis. Glut 3 expression was reduced by 85-95% compared with contralateral scrotal testis. A significant decrease in Glut 3 levels in abdominal testis was accompanied by an increase in scrotal testis Glut 3 content (80%, 144% and 212% at 10, 20 and 30 days, respectively) compared to age matched control rats. These results suggested that the degenerative changes in abdominal testis may be associated with decreased Glut 3 mediated glucose transport in seminiferous tubules and spermatogonia.

CD106 (VCAM-1) in testicular immunoregulation

The expression of CD18, CD49 d CD29 , CD44, CD54 and CD106 was studied in the testis of normal mice at various ages, in the cryptorchid testis, in the testis of estrogen-treated mice and in the testis of non-obese diabetic (NOD) mice, using immunocytochemistry to see which of these lymphocyte and endothelial adhesion proteins may be involved in lymphocyte regulation in the testis. CD18-, CD49 d CD29 -, CD44- and CD54-expressing cells were not found in the normal > 10-week-old BALB/c mouse testis. Leydig cells expressed CD106 strongly at this age. In contrast to the > 10-week-old testis, only very few interstitial cells of the 2-week-old normal mice expressed CD106. The expression of CD106 increased gradually with age so that at 6 weeks of age the expression of CD106 was moderate in the interstitial tissue. In the experimentally abdominal testis, CD106 was expressed in the interstitial tissue as strongly as in the contralateral scrotal testis. CD44- and CD18-expressing cells were occasionally present in the interstitial tissue of the abdominal testis, but not in the contralateral scrotal testis. CD54 was present in the epithelium of the ductuli efferentes. In the testis of the estrogen-treated mice, CD106 was expressed in the interstitial tissue as strongly as in the normal mice. Occasional CD44- and CD18-expressing cells were found in the testicular capsule. In the testis of adult NOD mice, CD106 was present in the interstitial tissue, but none of the other studied proteins. Immunoblotting of CD106 from the adult testis under reducing conditions demonstrated a single broad band with a M r of 51–65 kDa. This is a novel isoform of CD106. In a modified Stamper-Woodruff assay, lymphocytes bound to the testicular interstitial tissue. In co-incubations of native Leydig cells and lymphocytes, anti-CD106 antibodies prevented formation of Leydig cell-lymphocyte rosettes more than isotype-matched irrelevant control antibodies, suggesting that Leydig cell lymphocyte binding occurs through CD106-CD49d interactions. In lymphocyte cultures in the presence of anti-CD3, anti-CD28, the M r>5K fraction of testis extract (containing CD106 as shown by immunoblotting) and anti-CD106 or control antibody, anti-CD106 did not consistently affect T cell 3H-TdR incorporation. The present results suggest that CD106 expressed by the Leydig cells may act as an adhesion-promoting molecule or a co-stimulatory factor for T cells migrating to the testis.

Temperature-Mediated Germ Cell Loss in the Testis is Associated With Altered Expression of the Cell-Cycle Regulator p53

The dependence of spermatogenesis on the relatively cool environment of the scrotum is well known, and recent work has shown that germ cells undergo apoptosis upon exposure to abdominal temperature. p53 is a potent inducer of apoptosis and regulator of cell growth, and is found in high concentrations in the testis. The purpose of this study was to determine whether exposure of the testes to suprascrotal temperature was associated with alterations in testicular p53 expression. Male adult CD-1 mice were rendered unilaterally cryptorchid by surgically fixing one testis to the anterior abdominal wall while leaving the contralateral tests in the scrotum to serve as the euthermic control. p53 expression was evaluated in the cytoplasmic, soluble nuclear, and insoluble fractions by Western blot analysis with the monoclonal p53 antibody pAb240. The weights of the scrotal testes were unchanged over the 15 day study period. The weights of the cryptorchid testes remained stable for 7 days and then decreased by approximately 40% over the next two days. Histological evidence of germ cell loss was evident only after day 7. Altered expression of p53 protein in the cryptorchid testis was noted beginning on day 7, and consisted of the expression of a new 47 kD isoform of p53 in the cytosolic form and a 30 kD isoform in the soluble nuclear fraction. Scrotal testes showed no changes at any time point. These results demonstrate altered expression of the regulatory protein p53 beginning 1-2 days prior to the onset of germ cell loss following experimental unilateral cryptorchidism. Given the known function of p53 as an inducer of apoptotic cell death, these observations suggest a significant role for p53 in temperature-mediated germ cell loss.

Clinical aspects of male germ cell apoptosis during testis development and spermatogenesis

Apoptosis appears to have an essential role in the control of germ cell number in testes. During spermatogenesis germ cell deletion has been estimated to result in the loss of up to 75% of the potential number of mature sperm cells. At least three factors seem to determine the onset of apoptosis in male germ cells: (1) lack of hormones, especially gonadotropins and androgens; (2) the specific stage in the spermatogenic cycle; (3) and the developmental stage of the animal. Although male germ cell apoptosis has been well characterized in various animal models, few studies are presently available regarding germ cell apoptosis in the human testis. The first part of this review is focused on germ cell apoptosis in testes of prepubertal boys, with special emphasis on apoptosis in normal and cryptorchid testes. A higher percentage of apoptotic spermatogonia was seen in the cryptorchid testes than in the scrotal testes. The hCG-treatment increased the number of apoptotic spermatogonia. The hCG-treatment-induced apoptosis in spermatogonia had severe long-term consequences in reproductive functions in adulthood. Increased apoptosis after hCG-treatment was associated with subnormal testis volumes, subnormal sperm density and pathologically elevated serum FSH. This finding indicates that increased apoptosis in spermatogonia in prepuberty leads to disruption of testis development. To evaluate the role of apoptosis in human adult testes, apoptosis was induced in seminiferous tubules that were incubated under serum-free conditions in the absence or presence of testosterone. Most frequently apoptosis was identified in spermatocytes. Occasionally some spermatids also showed signs of apoptosis. In short term incubations apoptosis was suppressed by testosterone. Our findings lead to the conclusion that apoptosis is a normal, hormonally controlled phenomenon in the human testis. The role of apoptosis in disorders of spermatogenesis remains to be established.

Avaliação dos efeitos da ciclofosfamida nos testículos escrotal e retido em ratos jovens submetidos à criptorquia unilateral

Foi produzida criptorquia unilateral experimental em ratos pré-puberais. Tanto no testículo retido quanto no contralateral escrotal, foram encontradas alterações similares às observadas cm seres humanos. Essas alterações correspondem a um desenvolvimento testicular prejudicado, com degeneração da gônada. A administração crônica da droga imunossupressora ciclofosfamida, em doses baixas, evitou a deterioração do testículo tópico, a despeito de sua reconhecida ação deletéria para a espermatogênese. Tendo em vista que as lesões observadas atingem também o testículo escrotal e podem ser prevenidas pela ciclofosfamida, e discutida a possibilidade de que sejam causadas por reação auto-imune.

Is the ascending testis actually ?stationary?? Normal elongation of the spermatic cord is prevented by a fibrous remnant of the processus vaginalis

The processus vaginalis (PV) forms as a peritoneal diverticulum within the gubernaculum testis to allow the testis to exit from the abdominal cavity. Failure of its closure leads to inguinal hernias and hydroceles. Ascending testis, which is likely to be an acquired form of undescended testis, may also be part of the spectrum of failure of regression of the PV. At orchidopexy for cryptorchidism in older boys with a history of a scrotal testis in infancy, we find that the PV persists as a fibrous string, preventing normal elongation of the vas deferens and gonadal vessels with increasing size of the boy. We propose that the ascending testis is actually 'stationary', and is caused by persistence of a fibrous remnant of the PV. Seen in this light, ascending testes are directly related to inguinal hernias.

Is the ascending testis actually ?stationary?? Normal elongation of the spermatic cord is prevented by a fibrous remnant of the processus vaginalis

The processus vaginalis (PV) forms as a peritoneal diverticulum within the gubernaculum testis to allow the testis to exit from the abdominal cavity. Failure of its closure leads to inguinal hernias and hydroceles. Ascending testis, which is likely to be an acquired form of undescended testis, may also be part of the spectrum of failure of regression of the PV. At orchidopexy for cryptorchidism in older boys with a history of a scrotal testis in infancy, we find that the PV persists as a fibrous string, preventing normal elongation of the vas deferens and gonadal vessels with increasing size of the boy. We propose that the ascending testis is actually 'stationary', and is caused by persistence of a fibrous remnant of the PV. Seen in this light, ascending testes are directly related to inguinal hernias.

Treatment with human chorionic gonadotrophin for cryptorchidism: clinical and histological effects.

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

Apoptotic cell death in the normal and cryptorchid human testis: the effect of human chorionic gonadotropin on testicular cell survival.

Cryptorchidism is associated with histologic changes in the human testis apparent by 2 y of age. The mechanism accounting for these changes is still unknown. To clarify whether apoptosis plays a role in human cryptorchidism, we evaluated its occurrence in cryptorchid testes of 73 prepubertal boys, 43 of whom had received human chorionic gonadotropin (hCG) treatment. The histologic samples in our study included both scrotal and inguinal testes. Using an in situ apoptosis detection method, we were able to demonstrate that both interstitial cells and germ cells were affected and that the specific germ cells undergoing apoptosis were exclusively spermatogonia. Apoptosis in situ was further seen in both scrotal and inguinal tests; in scrotal testes the numbers of apoptotic spermatogonia were 170% of those seen in the cryptorchid testes (p < 0.05). Analysis of apoptotic DNA fragmentation from isolated DNA of a few selected biopsy samples served to validate our in situ findings. The amount of germ cell apoptosis analyzed during the 1st mo after hCG treatment was increased in both scrotal and inguinal testes compared with the amount before treatment (p < 0.001). But after the 1st mo it returned to the initial level, suggesting that hCG (and/or androgen) withdrawal increases germ cell apoptosis in the human testis. Our findings lead to the conclusion that apoptosis is a hormonally controlled, normal phenomenon in a human prepubertal testis and that cryptorchidism decreases its occurrence by reducing the number of germ cells capable of undergoing apoptosis.

Testicular microvascular blood flow: alteration after Leydig cell eradication and ischemia but not experimental varicocele.

Testicular microvascular blood flow is known to exhibit vasomotion, or pulsatile flow. In the present study we have used laser-Doppler flowmetry to study microvascular blood flow in the rat testis and to examine the response of the microvasculature to pharmacological stimulation and pathophysiological conditions. With a mean microvascular flow rate of 13.3 +/- 1.7 perfusion units (PU), the mean cycle amplitude was 3.4 +/- 0.6 PU, and the cycle frequency was 10.3 +/- 0.8 cycles per minute. Blood flow parameters did not differ between left and right testes, between scrotal testes and testes in a 35 degree C glass testicle receptacle, or among testicular regions. Perifusion of seminiferous tubules and their vasculature with 0.1 microgram/microliter epinephrine significantly reduced microvascular blood flow and eliminated vasomotion. Elimination of Leydig cells and intratesticular testosterone also eliminated vasomotion but did not significantly alter mean blood flow rates. Thirty days after imposition of experimental left varicocele (ELV) there were no significant changes in microvascular blood flow parameters. Testicular torsion of sufficient degree and duration to destroy spermatogenesis did not induce a change in mean microvascular blood flow rate 24 hours after repair of torsion, but testicular vasomotion was eliminated in the majority of animals. We conclude that microvascular flow is altered in some testicular pathologies and not in others. The mechanisms underlying changes in microvascular blood flow are at present unknown.

Effects of Unilateral Cryptorchidism on the Expression of Gonadotropin Receptor mRNA

Expression patterns of mRNAs of FSH and LH receptors were examined by Northern blot in adult rat testes after induction of unilateral cryptorchidism. At 4 weeks after the operation, signals of Northern blot were markedly increased in both receptor mRNAs in the abdominal testes as compared to those in the scrotal testes. In addition, there was a remarkable change in size pattern of LH receptor transcripts; the scrotal testes of cryptorchid rats and the intact testes of control rats expressed the transcripts of 7.0, 4.3, 2.5, and 1.8 kb, while the abdominal testes hardly expressed the transcript of 1.8 kb. This finding suggests that the expression of LH receptor mRNA is regulated locally within testis.

The Contralateral Testis in Cryptorchid Patients

We performed bilateral testicular Fine Needle Aspiration Cytology (FNAC) in a large group of unilateral cryptorchid subjects to characterize the tubular status related to the seminal pattern. In azoospermic and in severe oligozoospermic subjects the cytological picture of the contralateral testis showed similar lesions to those observed in the cryptorchid testis, while in moderate oligozoospermic subjects this analysis revealed the presence of a normal spermatogenic line and in normospermic subjects the presence of a compensatory activity of the tubular function. In conclusion, in unilateral cryptorchidism a frequent testicular damage in the orchidopexied testis and a concomitant tubular alteration in the contralateral scrotal testis exist, suggesting that cryptorchidism is the end point of different pathological conditions, including intrinsic (congenital) and extrinsic (anatomical) causes. FNAC of both testes could represent a tool for the clinician in the assessment of the tubular status in cryptorchid subjects, above all in presence of azoospermia or severe oligozoospermia. In these cases the existence of intratesticular spermatids or mature spermatozoa allows new assisted reproduction techniques using intratesticular germ cells to be used.

Extraabdominal fixation of the gubernaculum inhibits testicular descent in newborn rats

Within 48 hours after birth, newborn rats were anesthetized, and the distal tip of the gubernaculum was exposed extraabdominally, then fixed to the fascia of the groin on the left or the right side under a dissecting microscope (6x). In the sham-operated rats, the distal tip of the gubernaculum was merely exposed. Nonoperated rats were used as controls. In 60- to 90-day-old operated rats (n = 42), all testes were located in the superficial inguinal position, and the incidence of cryptorchidism was 100% on the operated side. In the sham-operated rats (n = 28), 27 of 28 testes descended into the scrotum, and one was located in the perineum; the incidence of cryptorchidism was 3.6% on the operated side. All testes also descended into the scrotum, and the incidence of cryptorchidism was 0% in controls (n = 20). The incidence of cryptorchidism was significantly higher among operated rats than among sham-operated or control rats ( P < .001). The testicular weight and the germinal epithelia of the cryptorchid testes were significantly lower than those of the scrotal testes in both sham-operated and control rats. Therefore it is suggested that the extraabdominal fixation of the distal tip of the gubernaculum in newborn rats induces cryptorchidism. The present model is considered to be a simple and useful one to investigate the process of testicular maldescent and inhibited growth of the testis in cryptorchidism.

Environmental temperature and cryptorchidism: effects on pregnenolone-sulfatase of mice testicular tissue.

This study examined the capacity of abdominal organs, such as the scrotal testis, exposed to environmental temperature to hydrolyze pregnenolone sulfate. The cryptorchid state of exposure to 34 degrees C during 14 days decreased testis weight by 38 and 23%. But the enzymatic activity (nanomoles of free steroid/testis) was significantly higher (p < .05) compared with the control. Moreover, a rise in the environmental temperature combined with cryptorchidism in mice, two conditions that induced testicular damage, has been related to the elaboration of factors capable of modifying, through paracrine mechanism, the androgen biosynthesis. The presence of this factor could lead to an increase in the hydrolysis of pregnenolone sulfate, but as for cryptorchidism or high environmental temperature exposure, when cryptorchid mice were exposed to temperatures of 34 degrees C an apparent synergism of both conditions produced a decrease of 66% in testis weight. It would appear that the steroid sulfatase is predominantly located in the interstitial epithelium. This study suggests that cryptorchidism and hyperthermia damage the tubular epithelium by different mechanisms.

Testes function and feedlot performance of bulls actively immunized against gonadotropin-releasing hormone: effect of age at immunization.

Testes function, feedlot performance, and carcass traits were evaluated in bulls actively immunized against gonadotropin-releasing hormone (GnRH) at different ages. Bull calves were randomly assigned to one of seven treatment groups (n = 15 calves/group). Calves were unimmunized (Group 1), immunized at 1.5, 4, 7, or 12 mo of age with a GnRH-keyhole limpet hemocyanin (KLH) conjugate (Groups 2 to 5, respectively), or castrated at 4 mo of age (Groups 6 and 7). Immunized bulls did not receive a secondary, or booster, immunization. Calves in group 6 received Synovex-C at castration and Synovex-S at weaning and feedlot entry. Anti-GnRH titer was evident at slaughter in all immunized bulls. However, the final immune response of bulls immunized at 1.5 mo was significantly lower than the response of bulls immunized at later stages of development. Final scrotal circumference and testis weight in bulls immunized at 4, 7, or 12 mo of age were significantly reduced relative to unimmunized bulls. The final live weight, feedlot gain, and carcass weight of immunized and unimmunized bulls did not differ (P > .05) from the same parameters in steers implanted with Synovex. Longissimus muscle area, marbling score, and backfat thickness did not differ between immunized and unimmunized bulls. The sex class score of the carcasses of immunized bulls did not differ from the score of steer carcasses. In contrast, a significantly higher proportion of carcasses from unimmunized bulls graded as bullock carcasses. Taken together, these data indicate that a single immunization against GnRH at 4 to 12 mo of age results in significant attenuation of testicular growth in bulls. These data also demonstrate that immunization against GnRH reduces the masculinity of carcasses from bulls, but does not affect feedlot performance, longissimus muscle area, marbling score, or backfat thickness. These results suggest that single immunization with the GnRH-KLH conjugate may have practical utility as a noninvasive alternative to surgical castration in management of beef cattle.

Abdominal position of the rat testis is associated with high level of lipid peroxidation.

Experimental cryptorchidism in the adult rat induces lipid peroxidation as a sign of oxidative stress. To further elucidate the role of free radicals and antioxidant enzymes in the degeneration of testis in cryptorchidism, we first studied testes of untreated rats before and after the normal testicular descent. In the second experiment, primary unilateral cryptorchidism was induced by surgically attaching one testis of each rat to the abdomen before testicular descent. The level of lipid peroxidation was detected by formation of fluorescent chromolipids and diene conjugates. At the age of testicular descent (18-21 days), the level of fluorescent chromolipids dropped to one third (p < 0.05). Correspondingly, the level of diene conjugates was 69% (p < 0.05) higher at 18 than at 30 days of age. The antioxidant enzyme activities did not change at the time of testicular descent. Primary unilateral cryptorchidism was induced at the age of 13 days. At 25 or 35 days of age, the level of diene conjugates was higher in the cryptorchid testes than in the contralateral scrotal testes (+39%, p < 0.01, and +51%, p < 0.001, respectively). In the abdominal testes, the mRNA of CuZn superoxide dismutase (SOD) was increased by 69% (p < 0.05) at 25 days, whereas by 35 days of age enzymatic CuZn SOD activity was slightly decreased and catalase activity increased. The present results show that the abdominal position of the testis, either before normal testicular descent or in experimental cryptorchidism, is associated with a high level of lipid peroxidation. The data provide evidence that increased production of reactive oxygen species could contribute to degeneration of the cryptorchid testis. The oxidative testis. The oxidative stress in the cryptorchid testis is not explained by inactivation of antioxidant enzymes.

A novel role for testicular descent; temperature-dependent induction of pertussis toxin-sensitive Gi protein function in postnatal rat Leydig cells.

The role of temperature and testicular descent in postnatal appearance of inhibitory guanine nucleotide-binding regulatory protein (G(i)) function was studied in the rat testis. Dispersed testicular cells of 5-day-old rats were incubated for 24 h at 32 or 37 C, then for another 24 h at the same temperatures in the presence and absence of pertussis toxin (PT; 100 micrograms/liter), and finally for a third 24-h period with cholera toxin (CT; 500 ng/liter) with or without PT. At both temperatures, PT treatment significantly (P < 0.05) increased the CT-stimulated cAMP output, but had no effect on basal cAMP production. When testosterone (T) production, as an indicator of Leydig cell function, was measured in the same incubation, CT-stimulated T production was greater at 32 C, but PT had no effect at either temperature. A similar finding was made when hCG (10 micrograms/liter), instead of CT, was used as the stimulus of T production. Hence, a functional G(i) protein is present in seminiferous tubules of 5-day-old testes cultured for 3 days at 32 and 37 C, but not in Leydig cells. We then examined the effects of longer exposure of 5-day-old testes to the two temperatures. After culture for 7 days with 0.1 microgram/liter ovine LH, the presence of PT at 32 C significantly (P < 0.01) enhanced CT-stimulated T production during the last 24 h of culture, but the PT effect was not observed when the culture was carried out at 37 C. Hence, G(i)-mediated modulation of Leydig cell function appears to require several days of induction at the lower temperature of 32 C. As the postnatal descent also changes the ambient testicular temperature, we next studied whether this event alters the G(i) protein function of Leydig cells. Five-day-old rats were rendered bilaterally cryptorchid or sham operated, and studied after 12 days. Testis weights did not differ between the abdominal and scrotal testes. In contrast, the basal and hCG-stimulated rates of T production were significantly (P < 0.01-0.05) higher in the scrotal testes. When dispersed cells of the scrotal and abdominal testes were incubated for 24 h at 37 C in the presence of CT with or without PT, enhancement of T production by PT was only observed in cells of the scrotal testes.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of Human Chorionic Gonadotropin Before Spermatic Vessel Ligation in the Prepubertal Rat Testis

After single stage Fowler-Stephens orchiopexy testicular atrophy is common. Previous experimental study in the scrotal testis of the adult rat has shown that ligation of the internal spermatic artery often causes focal testicular infarction or atrophy and exogenous human chorionic gonadotropin increases testicular blood flow. We questioned whether division of the internal spermatic artery in the undescended rat testis would also cause testicular injury and hypothesized that these changes might be prevented by administering human chorionic gonadotropin gonadotropin before vessel ligation. Two groups of 20-day-old Sprague-Dawley male rats were subjected to unilateral internal spermatic artery ligation. Group 1 (control) received no human chorionic gonadotropin, while group 2 received 10 IU human chorionic gonadotropin daily from days 3 to 17 of life. At 3 months testicular blood flow was quantitated using 141cerium radioactive microspheres. The results indicated that blood flow on the operated side was lower than on the nonoperated side but the change was not statistically significant. Human chorionic gonadotropin had no effect on blood flow to the operated testes. Gross testicular weights of operated versus nonoperated gonads were similar in rats that did and did not receive human chorionic gonadotropin. Pathological evaluation revealed normal histology in all testes. These results do not support the use of human chorionic gonadotropin preoperatively to stimulate collateral testicular blood flow.

Effect of human chorionic gonadotropin before spermatic vessel ligation in the prepubertal rat testis.

After single stage Fowler-Stephens orchiopexy testicular atrophy is common. Previous experimental study in the scrotal testis of the adult rat has shown that ligation of the internal spermatic artery often causes focal testicular infarction or atrophy and exogenous human chorionic gonadotropin increases testicular blood flow. We questioned whether division of the internal spermatic artery in the undescended rat testis would also cause testicular injury and hypothesized that these changes might be prevented by administering human chorionic gonadotropin before vessel ligation. Two groups of 20-day-old Sprague-Dawley male rats were subjected to unilateral internal spermatic artery ligation. Group 1 (control) received no human chorionic gonadotropin, while group 2 received 10 IU human chorionic gonadotropin daily from days 3 to 17 of life. At 3 months testicular blood flow was quantitated using 141cerium radioactive microspheres. The results indicated that blood flow on the operated side was lower than on the nonoperated side but the change was not statistically significant. Human chorionic gonadotropin had no effect on blood flow to the operated testes. Gross testicular weights of operated versus nonoperated gonads were similar in rats that did and did not receive human chorionic gonadotropin. Pathological evaluation revealed normal histology in all testes. These results do not support the use of human chorionic gonadotropin preoperatively to stimulate collateral testicular blood flow.

Effect of testicular damage induced by cryptorchidism on insulin-like growth factor I receptors in rat Sertoli cells.

The distribution and density of functional insulin-like growth factor I (IGF-I) receptors in cryptorchid and scrotal rat testes and epididymides during gonadal development were studied. Cryptorchidism was induced by unilateral gubernaculectomy in 4-day-old animals, and organs were studied at 15, 30, 60 and 90 days of age. Tissue membranes were assayed for 125I-labelled IGF-I binding. Characterization and specificity of binding sites showed that both normal and contralateral undescended testes and epididymides exhibited typical type 1 IGF receptors. In normal testes, IGF-I receptor density was 20.6 nmol g-1 wet mass at day 15, and decreased to 12.8 nmol g-1 wet mass at adult age (day 90). Cryptorchid testes showed IGF-I receptor concentrations similar to normal testes at day 15 and day 30, but in postpubertal stages displayed a divergent pattern, with a continuous increase at day 60 and day 90, reaching a higher density than those found for immature ages (62 nmol g-1 wet mass). Both normal and cryptorchid epididymides had a similar concentration and a comparable decrease in IGF-I receptors throughout development. In studies with immunohistochemical techniques (alpha IR-3 antibody), IGF-I receptors were found in primary spermatocytes, Sertoli cells and Leydig cells. Cryptorchid tubules showed a lack of germinal epithelium and a marked increase of immunoreactive IGF-I receptors in Sertoli cells, compared with normal tubules from scrotal testes. Intense immunoreactivity for IGF-I receptors was present in the principal cells of epididymal tubules in both normal and cryptorchid organs.(ABSTRACT TRUNCATED AT 250 WORDS)