Surgical repair of secondary right varicocele in rats with primary left varicocele: effects on fertility, testicular temperature, spermatogenesis, and sperm maturation.

To evaluate whether or not dilation of the right testicular vein is a constant finding in animals with left varicocele and to illustrate its contribution to the detrimental effect of a left varicocele on the right testis, an experimental varicocele model was produced in 40 rats. Ten other rats had a sham operation (group A). Seven weeks after the operation, all 50 rats underwent laparotomy and dilation of both testicular veins was seen in 23 rats, which were randomly assigned to group B (n = 11) and group C (n = 12). One week later, groups A and C underwent sham ligation of the right testicular vein, whereas group B rats underwent resection of this vein. At 84 days after the initial operation, group C rats showed a significant reduction in right epididymal sperm content, motility, and fertilizing capacity, right testicular weight, and right testicular vs. intraabdominal temperature difference when compared with groups A and B. Since surgical repair of the secondary right varicocele improved all the parameters indicating the harmful consequences of the primary left varicocele on the right testis, it appears that dilation of the right testicular vein contributes to the detrimental effect of a left varicocele on the right testis.     

Testicular blood flow in peripubertal and older rats with unilateral experimental varicocele and investigation into the mechanism of the bilateral response to the unilateral lesion

Testicular and reference organ blood flows and testicular temperatures were determined in peripubertal and mature rats with and without experimental left varicocele (ELV). Testicular blood flow and temperature were significantly increased bilaterally 30 days after surgery to induce unilateral varicocele, and this was the case in both the younger and older animals. It has not previously been known that the pathophysiological effects of ELV extended to the peripubertal testis. Previous experiments have demonstrated that the left testis is not necessary for the right testicular response to varicocele. In the present paper, animals were subjected to left orchiectomy simultaneously with the surgery to induce ELV. Thirty days later, the animals were divided into those with and those without the left spermatic vein varicosity. Testicular blood flow was determined in all these animals as well as in a separate group of control and experimental varicocele animals. The group of ELV animals with left spermatic varicosity demonstrated a significant increase in contralateral testicular blood flow while the ELV group without left spermatic varicosity did not. We speculate that left venous distention is involved in the mechanism for the contralateral response to unilateral varicocele.     

Effects of varicocele after unilateral orchiectomy and sympathectomy

An experimental varicocele was created in the adult rat by partial ligation of the left renal vein. There was a significant bilateral elevation of both testicular blood flow and temperature in the varicocele animals (p less than 0.01). Mean testicular blood flow for control and varicocele animals was 29.6 +/- 1.0 and 39.8 +/- 2.0 ml./min./100 gm. tissue, while mean testicular temperature was 34.4 +/- 0.1 and 35.3 +/- 0.2C, respectively. A left orchiectomy was combined with a left varicocele to determine if the left testis is essential for the right testicular response to a varicocele. Elevation of right testicular blood flow was not altered by left orchiectomy (p less than 0.05); however, right testicular temperature was no longer significantly increased. Mean right testicular blood flow and temperature for this group was 39.0 +/- 1.5 ml./min./100 gm. tissue and 34.2 +/- 0.15C, respectively. A left sympathectomy was combined with a left varicocele to ascertain if the right testicular response to the left varicocele was mediated through a neural pathway. A significant bilateral increase in testicular blood flow was noted with a left sympathectomy alone, and thereby masked the ability to evaluate the right testicular response to the simultaneous left sympathectomy and varicocele. Elevation of right testicular blood flow in response to the left varicocele is independent of the presence of a left testis and any immune response it may stimulate. The role of the sympathetic nervous system as a mediator of the bilateral varicocele effect remains undetermined.     

Effects of aescin on testicular repairment in rats with experimentally induced varicocele

This study was conducted to investigate the effects of aescin treatment in a rodent model treated with an experimentally induced varicocele. Experimental varicocele was induced by partial ligation of the left renal vein of rats. Aescin administration was performed daily for 4 weeks after the varicocele induction. Seven weeks later, a contrast‐enhanced ultrasound was performed of the rats' testis to assess testicular blood flow. The animals were sacrificed, and H&E staining was then used to evaluate testicular pathological changes and polymorphonuclear leucocytes density. Cauda epididymal sperm counts and motility were evaluated. Blood was collected for the measurement of follicle‐stimulating hormone, luteinising hormone and testosterone. Contrast‐enhanced ultrasound showed that there were significant decreases in testicular blood flow in the aescin‐treated groups compared with those in control varicocele group. Testicular oedema was detected in those rats treated with a varicocele but without aescin, while no oedema was found in the experimental group. H&E staining showed dysfunctional spermatogenesis in both cohorts; however, polymorphonuclear leucocytes density was significantly reduced in aescin‐treated groups. There was an increase in sperm counts of the aescin‐treated groups. Our study demonstrated that aescin could exert therapeutical effects on reversal of testicular lesions in varicocele rats.     

Testicular hypotrophy does not correlate with grade of adolescent varicocele

PURPOSE: Testicular hypotrophy is the most widely accepted indication for correcting adolescent varicocele. Previous studies in adolescents have shown a relationship between increasing grade of varicocele and the likelihood of testicular hypotrophy. As this relationship has significant clinical implications, we studied the correlation between grade and testicular volume disproportion in our adolescent varicocele population. MATERIALS AND METHODS: We reviewed the adolescent varicocele database at our institution. A total of 168 patients 8 to 21 years old were studied. We routinely calculated testis volumes using scrotal ultrasound. Testicular disproportion was calculated using the equation [(size of unaffected testis) - (size of affected testis)]/(size of unaffected testis) x 100%. Disproportion was categorized as less than 10%, 10% to 20% and more than 20%. Varicoceles were graded by an attending urologist with the patient standing, using the system of Dubin and Amelar. Analysis of variance and Pearson chi-square indicated no significant differences in volume differential between varicocele grades. RESULTS: Mean +/- SD volume differential was 18% +/- 15% for grade I, 25% +/- 20% for grade II and 19% +/- 14% for grade III. ANOVA revealed no significant difference in mean volume differential between the 3 varicocele grades (p = 0.10). When categorizing patients into 3 levels of volume differential (less than 10%, 10% to 20%, more than 20%) no significant correlation was observed between varicocele and volume differential (p = 0.48, chi-square test). CONCLUSIONS: Grade of varicocele does not correlate with presence or severity of testicular disproportion in adolescent boys with varicocele as measured by scrotal ultrasound.     

The effects of unilateral, experimental varicocele are not mediated through the ipsilateral testis

Unilateral varicocele has been associated with diminished male fertility in humans and with bilateral physiologic and histologic changes in the testis of humans and laboratory animals. In particular, left varicocele in Sprague-Dawley rats results in bilateral increases in testicular temperature and blood flow. The mechanism by which unilateral varicocele can cause testicular changes is not known. The purpose of the present study was to determine whether or not the presence of either the ipsilateral or contralateral testicle is necessary for these effects of the varicocele to occur in the opposite testis. Varicoceles were created in adult, male rats by partial constriction of the left renal vein. Bilateral testicular blood flow was measured by a radiolabelled microsphere distribution technique and testicular temperature was taken with a needle probe thermometer. Right or left orchiectomies were performed on selected animals at the time of surgery to establish the unilateral left varicocele. Animals were studied 30 days after surgery. Mean testicular blood flow was significantly increased (P less than 0.01) in all animals having a left varicocele when compared with animals not having a varicocele regardless of whether a unilateral orchiectomy was performed. Likewise, the mean difference between intraabdominal temperature and intratesticular temperature (delta T) was significantly decreased in all groups of animals having varicoceles when compared with groups without varicoceles whether or not an orchiectomy had been performed. Thus, the studied bilateral effects of left-sided, experimental varicocele in the rat are not dependent upon the presence of a left testicle.     

Effects of surgical repair of experimental left varicocele on testicular temperature, spermatogenesis, sperm maturation, endocrine function, and fertility in rabbits.

To evaluate the effectiveness of surgical correction of varicocele in restoring the function of the varicocelized testicle, experimental varicoceles were created in 16 male rabbits by partly ligating the left lumbotesticular trunk. Five control rabbits received a sham operation (group A). Two months later, eight of the varicocelized rabbits underwent surgical repair by ligation and cutting of the dilated left testicular vein (group B). The remaining eight varicocelized animals did not receive any additional treatment (group C). Five months after the initial operation, group C animals had a significantly lower sperm concentration, sperm motility, bilateral testicular androgen-binding protein activity, bilateral testicular vein testosterone concentration, bilateral testicular versus intraabdominal temperature difference, and fertility when compared with groups A and B. These findings suggested that the surgical repair of an experimental varicocele in the rabbit can significantly improve the parameters indicating the harmful effects of the varicocele on the testicles.     

The effect of varicocele repair on testicular volume in children and adolescents with varicocele

PURPOSE: We investigated the effect of varicocele repair on testicular volume according to age in children and adolescents and review the long-term results of varicocele surgery. MATERIALS AND METHODS: The study included 39 boys 11 to 19 years old with clinical palpable varicocele who underwent varicocele surgery with at least 1 year of postoperative followup. Preoperative and postoperative testicular volumes were monitored and measured with an ellipsoid Prader orchidometer. Physical examination findings (testicular volumes and testicular consistency) in all boys, and serum hormone values and semen parameters in 16 adolescents were recorded and compared before and after surgery. RESULTS: Left unilateral varicocelectomy was done in 29 boys (74%) and bilateral varicocelectomy in 10 (26%). While no postoperative hematoma, infection or testicular atrophy was observed, 1 boy (2.5%) had varicocele recurrence and 2 boys (5.1%) had minimal hydroceles that required no intervention. Significant increases were observed in postoperative sperm concentration (p = 0.01), total motile sperm count (p = 0.009), testis volume (p = 0.000) and serum testosterone level (p = 0.014). All 15 boys with preoperative soft testis had normal testicular consistency postoperatively. Of the 19 boys with preoperative testicular atrophy 10 (53%) did regain normal testicular growth, while 9 (47%) retained testicular volume loss after surgery. When comparing preoperative to postoperative increase in testicular volume according to age in all boys, the mean was statistically significantly higher in boys younger than 14 years (left testis p = 0.037, right testis p = 0.000). CONCLUSIONS: Testicular consistency achieved normal firmness after varicocelectomy in all boys with preoperative soft testis. While there was catch-up growth in comparison to the contralateral testis, testicular consistency improved but testicular volumes may not increase significantly after varicocele repair at ages older than 14 years. However, in these adolescents postoperative semen parameters and serum hormone values may significantly improve regardless of testicular volume. Therefore, boys with varicocele and their families should be fully informed in light of these findings.     

Testicular hypofunction caused by activating p53 expression induced by reactive oxygen species in varicocele rats

We investigated the mechanism of the testicular hypofunction induced by hypoxia in varicocele rats. Varicocele was induced by partial ligation of the left renal vein. Seven weeks later, left testis mass index was measured. The sperm counts and motility were tested by CASA. The change of seminiferous tubule tissue was observed by HE staining. The reactive oxygen species (ROS) level in left testicular tissue was measured by ELISA, and the expressions of HIF‐1α and p53 were detected by immunohistochemistry and Western blot. The left testis mass index and the sperm motility were significantly lower in surgery group. By HE staining, the left seminiferous epithelial cell arrangement was incompact, disordered and vacuolated in surgery group. The ROS level in surgery group was significantly higher than the other groups. The results of immunohistochemistry and Western blot indicated that the expressions of HIF‐1α and p53 increased significantly in surgery group. Our study demonstrated that varicocele caused hypoxia that could cause the rise of ROS level to induce the increase of p53 expression, leading to the decrease of testis mass index and changes of seminiferous tubules, which would reduce sperm motility and result in male infertility eventually.     

Total ligation of the left renal vein in the dog: an inappropriate model for varicocele

Induction of varicocele was attempted by ligation of the left renal vein (LRV) in male dogs (Group I). Before the operation and in the 4-month post-operative period, sperm count, sperm motility, and sperm morphology of Group I (n = 8) dogs were compared to sham operated animals (Group II, n = 5). Furthermore, haemodynamics as well as testicular and vascular morphology were studied. In Group I, changes in diameter and consistency of the spermatic cord were temporary. Semen quality was reduced significantly during the second month after ligation of the LRV, but improved thereafter. Haemodynamic studies revealed that LRV blood pressure was increased significantly in Group I dogs. An extensive venous collateral network replaced the occluded LRV. Retrograde blood flow in the left testicular vein (LTV) was observed only in the proximal part of the LTV of Group I dogs. In Group II dogs numerous pairs of sufficient valves prevented reflux into the LTV. Histological examination revealed that spermatogenesis was not impaired and that the left pampiniform plexus had not changed. The number of Leydig cells was decreased slightly in Group I dogs. Sufficient valves in the LTV prevented formation of a permanent varicocele.     

Induction of varicocele in the dog: I. Partial ligation of the left renal vein does not induce a varicocele in the dog

Induction of varicocele was attempted by partial ligation of the left renal vein in 10 male dogs. The effects on sperm count, sperm motility, and sperm morphology, as well as on hemodynamics, were assessed. Furthermore, testicular, vascular, and kidney morphology was studied. Changes in the diameter and consistency of the left spermatic cord were found to be temporary. Total sperm count, sperm motility, and the total number of oval forms were not significantly altered. Hemodynamic studies revealed a renocaval pressure gradient, but retrograde flow in the distal part of the left testicular vein could not be observed by arteriography. A collateral network was found to compensate for the restricted left renal vein. Histologic examination revealed no damage to the seminiferous epithelium. Changes were not found in the kidney and left pampiniform plexus. Although some temporary changes induced by the partial ligation of the left renal vein are suggestive of varicocele, this hemodynamic study shows that the presented dog model does not mimic varicocele as encountered in man.     

Testicular volume and semen parameters in patients aged 12 to 17 years with idiopathic varicocele

PurposeVaricocele is potentially a progressive condition that may affect fertility. The authors have encouraged sperm banking for their postpubertal patients with varicocele and aim to evaluate the sperm parameters in this cohort of patients.MethodsWith institutional ethical approval, sperm variables (volume, concentration, and forward motility) of patients with postpubertal varicocele who opted for sperm banking were prospectively recorded. The following parameters were also acquired: (a) ultrasound measurement of testicular volume, (b) clinical grade, and (c) venous Doppler. Patients were divided into 2 groups: symmetrical testis (group A) and asymmetrical testis (group B). Testicular asymmetry was defined as greater than 20% difference in testicular volume compared with contralateral testis. Sperm parameters were compared between groups A and B using Mann-Whitney U test and P < .05.ResultsFifteen patients were included: 10 in group A and 5 in group B. Median semen concentration in group B was significantly lower than group A (3 vs 26 million/mL; P = .04). One hundred percent of group B failed World Health Organisation adult criteria for normal spermiograms compared with 50% of group A.ConclusionsSperm concentration and quality was lower in patients with asymmetrical testis. Testicular dysfunction may be present before the onset of testicular hypotrophy. When testicular hypotrophy is present, testicular dysfunction is very likely.     

Effect of experimental varicocele in rats on testicular oxidative stress status

The present experiments were undertaken to determine the levels of MDA, SOD and catalase in the testis of adolescent rats with experimental left varicoceles. Male Wistar rats, 7 weeks old and weighing 160-170 g, were randomly allocated into three groups. The first group of rats underwent partial ligation of the left renal vein (n = 15). The second group of rats underwent a sham operation (n = 7) and the third group acted as controls (n = 7). Animals were sacrificed 6 weeks after surgery and dilatation of the internal spermatic veins was observed. Levels of MDA, SOD and catalase activity were measured in testis. The experimental left varicocele group showed severe testicular changes compared to other groups. The mean MDA (SEM) levels in right and left testicular tissues of varicocele bearing rats, sham-operated rats, and control rats were 0.48 +/- 0.24 and 0.31 +/- 0.11, 0.22 +/- 0.02 and 0.35 +/- 0.12, 0.62 +/- 0.29 and 0.13 +/- 0.05, respectively (P > 0.05). The mean SOD (SEM) levels in right and left testicular tissues of varicocele bearing rats, sham-operated rats, and control rats were 7,790 +/- 606 and 6,974 +/- 574, 7,475 +/- 1,517 and 7020 +/- 1,106, 8,727 +/- 1,188 and 9,019 +/- 1,129, respectively (P > 0.05). The mean catalase (SEM) levels in right and left testicular tissues of varicocele bearing rats,sham-operated rats, and control rats were 75.77 +/- 11.5 and 53.82 +/- 10.1, 91.94 +/- 14 and 94.90 +/- 32, 65.40 +/- 5.7 and 90.93 +/- 16.4, respectively (P > 0.05). Our results suggest that oxidative status, which reflects a relative balance between reactive oxygen species (ROS) generated and ROS scavenged, may not be responsible for the testicular dysfunction associated with experimentally induced varicocele during adolescence in rats.     

Improvement of sperm count and motility after ligation of varicoceles detected with colour Doppler ultrasonography

The debate regarding the efficacy of varicocele ligation for improvement of semen parameters and pregnancy rates is ongoing. In addition, no consensus exists as to the benefit of treatment of subclinical varicoceles. The aim of this study was to investigate, retrospectively, the effect of high ligation of both subclinical and clinical varicoceles on sperm count and motility. The value of several factors from history-taking and physical examination for the prediction of successful varicocelectomy was analysed. A total of 139 patients, operated on for a unilateral varicocele on the left side, were studied. Varicoceles were subclinical in 73 patients, based on colour Doppler ultrasonography, and 66 varicoceles were clinical, based on palpation in addition to ultrasonography. Comparison of semen parameters before and after surgery revealed a significant improvement. The median sperm count increased from 10.0 to 14.7, and from 18.2 to 28.6 million/ejaculate, in patients with subclinical and clinical varicoceles, respectively ( p  < 0.001). The percentage improvement in median sperm count in subclinical varicoceles was not statistically different from the improvement in clinical varicoceles. Mean progressive motility improved significantly after ligation ( p  < 0.001). The improvement in motility in subclinical varicoceles, from 16 to 23%, was significantly larger than the 24 to 27% improvement in clinical varicoceles. The increase in sperm count was related positively to testicular volume before surgery ( p  < 0.05). The increase in sperm motility was significantly lower in patients with a history of cryptorchidism ( n  = 22, p  < 0.05). The present data show that ligation of varicoceles detected using Doppler ultrasonography, whether palpable or not, results in an increase in sperm concentration and motility.     

Varicocele ligation on free testosterone levels in infertile men with varicocele

We have analyzed the effects of varicocele ligation on free testosterone levels, and investigated the interrelationships between free testosterone and fertility. The records were retrospectively evaluated for 42 infertile patients who underwent varicocele ligation, with serum free testosterone levels, follicle stimulating hormone (FSH), lutenizing hormone (LH), testosterone, estradiol, prolactin, ejaculated volume, sperm concentration and motility before and after surgery. Serum free testosterone levels increased from 12.97+/-4.16 to 13.59+/-3.93 pg/mL, but the difference was insignificant. The differences before and after surgery of patients in sperm concentration and motility were also insignificant. However, in free testosterone increasing group, the sperm concentration and motility increased significantly, from 4.05+/-4.35 to 7.90+/-8.19 million/mL (P=0.01) and from 30.64+/-21.87% to 41.00+/-22.00%, respectively (P=0.03). The increase in serum free testosterone level by varicocele ligation results in a significant improvement in sperm concentration and motility.     

Effects of epidermal growth factor on sperm content and motility of rats with surgically induced varicoceles

Aim:To investigate the effect of epidermal growth factor(EGF)on the sperm content and motility of the varicocelizedrats.Methods:Forty-eight male Wistar rats were randomly divided into five groups.Experimental varicocele wasinduced by partial ligation of the left renal vein in the varicocele,the varicocele repair,the varicocele with EGF and thevaricocele repair with EGF groups,whereas the control group only received a sham induction of varicocele.Surgicalrepair of varicocele was performed 4 months later in the varicocele repair and varicocele repair with EGF groups.EGF administration was performed daily by s.c.injection in the varicocele with EGF and varicocele repair with EGFgroups at the dose of 10μg/(kg.day)from the next day of the second surgery.One month later,all animals werekilled and bilateral cauda epididymal sperm counts and motility were evaluated.Results:The mean sperm count andpercentage of motile spermatozoa were significantly higher bilaterally in the varicocele with EGF group than in thevaricocele group(P<0.05).They were also significantly higher bilaterally in the varicocele repair with EGF groupthan in the varicocele repair and the varicocele with EGF groups(P<0.05).Conclusion:EGF can improve bilateralepididymal sperm content and motility of the rat with surgically induced varicocele.The administration of EGF incombination with surgical repair is more effective than surgical repair or EGF administration alone.EGF might beuseful for the treatment of infertility induced by varicocele.(Asian JAndrol 2006 Nov;8:713-717)     

THE ADOLESCENT VARICOCELE I: LEFT TESTICULAR HYPERTROPHY FOLLOWING VARICOCELECTOMY

PURPOSE: Ipsilateral testicular catch-up growth has been reported to occur in approximately 80% of adolescents with varicoceles following unilateral varicocelectomy. We have been observing not only catch-up growth, but hypertrophy (left at least 10% larger than right testicular volume) in some adolescents postoperatively. To our knowledge this phenomenon has not been previously described. We assess the incidence of left testicular hypertrophy following ipsilateral varicocele ligation and whether it is related to age at operation and/or procedure performed. MATERIALS AND METHODS: We reviewed the records of 42 patients who underwent unilateral left varicocelectomy for asymptomatic varicoceles. Testicular volume was determined before and after surgery, and all patients were followed for a minimum of 6 months. Indication for surgery was ipsilateral left testicular hypotrophy in 23 cases, grade 2 to 3 varicocele with palpably softer ipsilateral left testicle in 5, grade 3+ varicoceles in 12, an exaggerated response to gonadotropin-releasing hormone stimulation test in 1 and persistent pain in 1. Average patient age at operation was 14.7 years (range 9 to 22) and average followup was 22 months (range 6 to 84). Patients were stratified according to Palomo versus modified Ivanissevich technique and age at operation. Testes were measured using the Takihara ring orchidometer with relative volume of the left testis expressed as a percentage of the right testis. Results were compared in different age groups as well as by procedure performed to correct the varicocele using chi-square analysis. RESULTS: Left testicular hypertrophy developed in 13 of 32 patients (43.8%) who underwent a Palomo repair and in 3 of the 10 (30%) who underwent a modified Ivanissevich repair. When compared by age at operation, 8 of 20 patients (40%) 14.7 years old or younger had left testicular hypertrophy compared to 8 of 22 (36.4%) older than 14.7 years. Differences between these groups were not statistically significant. CONCLUSIONS: Ipsilateral testicular hypertrophy occurs in a substantial number of adolescents following varicocele ligation. This phenomenon does not seem to be dependent on age at surgery or type of varicocele repair.     

Improvement of semen characteristics after surgical repair of bilateral testicular varicocele as compared to unilateral varicocele patients

The operative treatment for surgical repair of bilateral testicular varicoceles was evaluated in terms of the improvement achieved in the sperm density and percentage progressive motile sperm. These parameters were compared for 27 cases of bilateral varicocele diagnosed by palpation and subjected to bilateral high ligation of the internal spermatic vein and for 40 cases of left unilateral testicular varicocele. There were no significant differences in preoperative values (such as sperm density; progressive motile sperm; serum levels of luteinizing hormone, follicle-stimulating hormone, and testosterone; and Johnson's score count) between the bilateral and unilateral testicular varicocele groups. The improvement in postoperative sperm density in the cases with bilateral testicular varicocele was apparently less satisfactory than in the cases with testicular varicocele only on the left side.     

Predictors of improved seminal characteristics by varicocele repair

The aim of this study was to investigate predictors of the improvement of semen characteristics after low ligation for patients with varicoceles. The records of 97 oligozoospermic patients who underwent microsurgical left or bilateral inguinal varicocele repair were retrospectively evaluated. We assessed factors that could be predictors of the improvement of semen characteristics using logistic regression analysis. We evaluated age, testicular volume, varicocele grade, serum follicle-stimulating hormone (FSH), luteinising hormone, testosterone, sperm concentration and motility before low ligation. Among the 97 patients, sperm concentration improved from 6.4 ± 5.8 to 24.2 ± 35.1 million ml⁻¹ and sperm motility increased from 32.8 ± 24.9% to 41.0 ± 14.6% in 55 patients (57%). In logistic regression analysis, pre-operative serum FSH and testosterone concentration were predictors of sperm concentration improvement. Varicocele repair improved sperm concentration and motility. Low serum FSH and high testosterone are significant factors predicting the improvement of semen characteristics before low ligation.     

Testicular function in varicocele

Testicular testosterone concentration serum testosterone, LH and FSH, sperm count and testicular histology were evaluated in 17 patients with varicocele. Testicular testosterone was either normal or high (mean 906 +/- 723 ng/g of tissue), and serum testosterone was within the normal range in most patients. Serum LH was elevated in half of the patients. The degree of testicular damage observed was extremely variable and correlated with sperm analysis. Testicular testosterone tended to be higher in patients with severe microscopic lesions of the testis. It is concluded that even though Leydig cell function is partially altered, this deficiency is compensated by LH stimulation and therefore, failure of spermatogenesis is not secondary to low testosterone levels.