Testis Parenchyma Research Articles

Fibrotic lesions in the testis of bulls and relationship to semen quality

Ultrasonography of the testes was done in bulls at three locations in western Canada (n=325) and one in Argentina (n=387) to determine the prevalence of fibrotic lesions and to examine the relationship between fibrotic lesions and location, age, breed, right compared with left testes, testis size and semen quality. Fibrotic lesions were common in the testes of bulls raised under intensive rearing conditions in western Canada as well as in the more extensive rearing conditions of Argentina. Fibrotic lesions appeared as early as 5-6 months of age and the number of cases continued to increase until at least 12-14 months of age. The severity of lesions increased in some cases during this period; however, it appears that the development of lesions occurred during a finite period of pubertal development. It is unlikely that the prevalence of lesions is influenced by breed, right compared with left testes or testis size. The cause of the lesions is unknown, but there was an association between the development of fibrotic lesions and an outbreak of BRSV disease in Argentina in one group of bulls. There was some indication that during the active process that leads to fibrosis spermatogenesis is adversely affected; however, the presence of a large number of fibrotic lesions that may occupy as much as 50% of the testis parenchyma did not preclude the production of a greater percentage of sperm with normal morphology.

Seasonal variation in expression and localization of testicular transforming growth factors TGF-β1 and TGF-β3 corresponds with spermatogenic activity in roe deer

Adult roe deer males show hormonally controlled seasonal cycles of testicular growth and involution. Mediation of endocrine signals likely requires variable production of testicular growth factors for regulation of testis function. Here we studied the expression pattern of transforming growth factors (TGFs) beta1 and beta3. Total RNA from testis parenchyma was extracted monthly and analysed using quantitative reverse transcriptase PCR. The localization of mRNAs was determined by in situ hybridization, and corresponding proteins were visualized immunohistochemically. Both factors showed different expression levels and different seasonal expression patterns. The TGF-beta1 mRNA content was up to 45 times higher than that of TGF-beta3. Compared with its lowest level in May, TGF-beta1 expression was slightly enhanced during pre-rut (June/July). TGF-beta3 expression increased 5-fold from April to June/July and decreased thereafter to its low in December. This corresponded with changing numbers of spermatocytes and round spermatids, in which both TGF-beta3 mRNA and the protein were mainly localized. The TGF-beta1 mRNA was found in interstitial cells, mainly during the non-breeding season, but also in spermatocytes and spermatids during activated spermatogenesis. The translation product was localized in few spermatogenic cells only. The results suggest that TGF-beta1 and -beta3 are important in regulating seasonal spermatogenesis of roe deer with diverse functions affecting interstitial and spermatogenic cells.

Testicular FGF-1 protein is involved in Sertoli cell–spermatid interaction in roe deer

Roe deer (Capreolus capreolus) is a seasonal breeder showing extreme changes in spermatogenic activity. It is an excellent model to study the regulation of testicular activation and regression by endocrine signals and paracrine effectors such as growth factors. Previous studies on FGF-1 mRNA showed a special seasonal expression pattern in roe deer testis. This was difficult to explain by their exclusive localization in interstitial and Sertoli cells and without detection of the translation product. Therefore, the cellular localization of the FGF-1 protein was studied during a complete annual cycle. Parenchyma samples were collected bimonthly and prepared for histological and immunohistochemical investigations. A polyclonal rabbit anti-bovine FGF-1 antibody was used for indirect immunohistochemistry. Seasonal changes in the cellular composition of roe deer testis parenchyma were quantified by morphometry and means of computer aided image analysis. In the tubular compartment FGF-1 protein was exclusively (and stage-specific) present in elongating spermatids. This cell type occurs shortly before (June) and during the rutting season (August) only. In interstitial cells FGF-1 is detectable throughout the whole year. Results suggest FGF-1 being involved in Sertoli cell-spermatid communication and could also serve as a survival factor for somatic cell populations within the testis. The occurrence of the protein indicates an increased expression of this factor during activated spermatogenesis.

Histological organization of roe deer testis throughout the seasonal cycle: variable and constant components of tubular and interstitial compartment.

Seasonally regulated breeding in roe deer, Capreolus capreolus, is associated with significant changes in testis mass, structure and function. This study has quantified seasonal changes of morphometric parameters and cellular composition in roe deer testis parenchyma. Tissue samples were collected bimonthly during a complete annual cycle. Morphometric parameters of seminiferous tubules were measured and the number of different cell types was counted using a computer-aided image-analyzing system. A scheme of eight tubular epithelium stages for active spermatogenesis was devised according to the spermatid development. Stage I is characterized by the occurrence of new round spermatids, stage IV by spermiation and stage VIII by the meiotic division of spermatocytes. The average diameter of seminiferous tubules varied between 88.4+/-3.6 micro m (February) and 216.8+/-9.2 micro m (June). Also numbers of spermatogonia, spermatocytes and spermatids per tubule cross-section showed considerable seasonal changes. In December and February the germinative epithelium mainly consists of Sertoli cells and spermatogonia. In February, the first differentiated spermatogonia enter meiosis, and in April even spermatids occasionally occur, which reach their highest numbers during the rut in August. Both the expansion and the proportion of tubular and interstitial compartment change seasonally and result in differing cell densities. Assuming numerically constant populations of Sertoli cells and interstitial cells during the entire year, the hypothetical cell numbers per mm(2) of the tubular and interstitial areas were calculated for the seasonally variable total areas of tissue cross-sections. The concordance of these theoretical values with measured cell densities provided evidence that the total numbers of Sertoli cells, as well as interstitial cells, remain really constant throughout the seasonal cycle. The exact quantification of variable and constant components provides basic data for characterization of cell type and stage-specific processes of spermatogenesis.

A morphological study of simple testicular cysts in the ostrich ( Struthio camelus)

Simple testicular cysts are rare in mammals and of unknown aetiology, but dietary conditions have been implicated in this phenomenon in poultry. This study characterises the structural features of simple intratesticular cysts in the ostrich. Seven testes from a total of 15 sexually mature ostriches slaughtered during the breeding season were used. The testes contained multifocal, fluid-filled, unilocular cysts which were lined by a simple squamous or low cuboidal epithelium and surrounded by a thick layer of fibrous connective tissue. The cysts developed within seminiferous tubules and displayed morphological features similar to those reported in man and domestic poultry. The testis parenchyma revealed several foci composed of intermingled normal seminiferous tubules and variably sized intratesticular cysts. The atrophic tubules lay within a mass of hyperplastic, fibroblastic intertubular connective tissue in the proximity of large cysts and their formation appeared to result from hydrostatic pressure exerted by cysts. Morphological evidence supports a continuous process of cyst formation in the affected testis and a concomitant progressive loss of atrophic seminiferous tubules. A pathogenetic scenario of cyst formation and the effect of simple cysts on testicular histology has been proposed. Although the course of this phenomenon remains unknown, its impact on the fertility of this economically important bird deserves closer scrutiny.

Efecto de la inmunización contra testosterona sobre las características testiculares de toros Cebú

The primary aim of this study was to evaluate the testicular size and sperm production in adult bulls, immunized against testosterone during the prepubertal age. Zebu crossbred bulls (n=4 per group) were immunized prepubertally with ovalbumin (OVA), or with 5 mg (T5), or 10 mg (T10) of a testosterone-ovalbumin conjugate. Non-immunized bulls were used as a control group. At castration (29 months of age), the scrotal circumference (SC) was recorded and seminal quality was evaluated. Testes and epididymides were collected from each bull, and their weight recorded, as well as the testis parenchyma weight. Testicular tissue samples were collected for histology studies and daily sperm production quantification. Bulls from T5 group had larger SC (P0.05) for epididymis weight, Leydig cell density, diameter of seminiferous tubules, semen characteristics, and LH and testosterone concentrations. In conclusion, immunization with the small dose of the testosteroneovalbumin conjugate in prepubertal bulls increased testicular size and daily sperm production in the adult animal, with no apparent effect on seminal quality and body weight.

Gonadal sperm reserve in purebred Landrace and Large White boars of high average daily gain

The present study investigated the effects of average growth rate (AGR) levels and age on the number of sperm cells per gram of testis parenchyma and on the gonadal reserve in Landrace (LD) and Large White (LW) boars. In Experiment 1, the effects of breed (LD, LW), level of AGR from birth up to 90 days of age (Level 1: 384 +/- 32 g/day; Level 2: 512 +/- 22 g/day; Level 3: 624 +/- 41 g/day), and age (13, 15, 17, 19 and 21 weeks) on testicular cell concentration were evaluated. Data were analyzed under a 2 x 3 x 4 factorial design. There were significant effects associated with breed (P < 0.001) and age (P < 0.001) but not with AGR (P > 0.05) on sperm cell number per gram of testicular parenchyma. The number of cells increased with age and was greater in LW than in LD young boars, mainly those up to 19 weeks of age. In Experiment 2, the effect of two AGR levels (Level 1: 649-694 g/day; Level 2: 813-885 g/day) from birth up to 100 kg body weight on the number of sperm cells per gram of testis parenchyma and on the gonadal reserve was investigated using 59 purebred LD and LW boars. The boars were castrated at 23, 25, 29 and 33 weeks of age. Age of boars significantly affected gonadal sperm reserve and the number of sperm cells per gram of testicular tissue (P < 0.001). Breed of boars and AGR Levels did not significantly affect number of sperm cells and gonadal sperm reserve (P > 0.05). It was concluded that the number of sperm cells in the testicular tissue of young boars is influenced by their breed and age, but not by the level of their AGR.

Testicular development, histology, and hormone profiles in three yearling angus bulls with spermatogenic arrest

This article discusses the interactions between testis criteria and hormone profiles in Angus bulls with spermatogenic arrest. From 2 to 12 months (mo), testis diameter and hormone concentrations (basal and GnRH-stimulated) were evaluated in 27 bulls. At 12 mo, testes were excised. The z statistical test was used to determine whether parameters in three infertile bulls were different (P < 0.05) from those in 24 bulls with normal spermatouenesis. Bull 1 had Sertoli cell-only syndrome and Bull 2 had 90% of the tubules without germ cells and only A1 spermatogonia in the remaining. In Bull 3, germ cells did not advance beyond the primary spermatocyte stage. At 12 mo, testes of Bull 1 (99 g), Bull 2 (105 g) and Bull 3 (32 g) weighed less than those of normal bulls (251.5 +/- 56 g). Sertoli cell numbers/testis in Bull 1 (3.8 x 10(9)) and Bull 2 (4.3 x 10(9)) were not different from those in normal bulls (4.9 +/- 0.3 x 10(9)), but were reduced in Bull 3 (1.6 x 10(9)). The number of Leydig cells per gram of testis parenchyma was higher in Bull 1 (5.4 x 10(7)), Bull 2 (7.3 x 10(7)) and Bull 3 (19 x 10(7)) than in normal bulls (3.6 +/- 0.2 x 10(7)). In Bulls 1 and 2, basal and GnRH-stimulated LH, FSH, testosterone (T), androstenedione (delta4A) and estradiol 17-beta (E2) were within normal ranges at most ages. However, basal FSH and LH were greater in Bull 3 than in normal bulls, probably the causes for higher Leydig cell density. Also in the same animal, GnRH induced lower responses in LH and FSH, consequence of low basal T and E2 at some ages. Basal and GnRH-stimulated delta4A in Bull 3 were greater than in normal bulls after 6 mo, indicating impairment of Leydig cell differentiation. Deficiency in hormone secretion did not appear to be the cause of infertility, which points toward impaired gonadal responses or secretion of intratesticular factors, or genetic defects. Moreover, infertile animals may not always show pronounced changes in hormone secretion, but evaluation of testis growth around puberty can help identify those animals that do not have proper gonadal development.

Testis Sperm Extraction (TESE) Is Effective in the Azoospermic Male with a History of Prior Chemotherapy

Objectives: Approximately 50% of the total group of men with non-obstructive azoospermia (NOA) will have sperm found within the testis parenchyma which can be used with ICSI to achieve biological paternity. Questions: what are the rates of sperm retrieval and pregnancy for subgroups with NOA, e.g., post-chemotherapy? The purpose of this study is to define the success of TESE and the pregnancy rates for only those men who are azoospermic due to chemotherapy so as to be able to counsel this type of NOA patient as best possible. Materials and Methods: 7 NOA men subsequent to chemotherapy and who underwent TESE comprise the study group. Harvested tissue was analyzed and cryopreserved if sperm were present and thawed homogenate used for subsequent cycles of ICSI. Age range: 28 to 43 years. legendAge at chemolegendC: cyclophosphamide; V: vincristine; D: doxorubicin; Chl: chlorambucil; Pro: procarbazine; P: prednisone; B: bleomycin; Cis: cisplatin.Reason for chemoChemo agents usedSperm present12Systemic LupusChlNo21Testis CancerCis, V, BNo4Nephrotic SyndromeC, P. ChlNo23Histiocytic lymphomaMechlorethamine, V, Pro, PYesPending24Hodgkin'sV, C, DYes7Twins lost at 25 weeks15Ewing's SarcomaV, D, Actinomycin DYes1Ongoing pregnancy15Testis CancerCis, Vp-16, BYes1Ongoing pregnancylegend C: cyclophosphamide; V: vincristine; D: doxorubicin; Chl: chlorambucil; Pro: procarbazine; P: prednisone; B: bleomycin; Cis: cisplatin. Open table in a new tab Results: Of the 7 men, 4 (57%) had sperm found during TESE. These 4 men were all pubertal or post-pubertal at the time of chemotherapy. The fertilization rate ranged from 58–80%. The twin aborteses were normal in appearance, premature rupture of membranes the cause. Conclusion: For the subgroup of men with NOA due to prior chemotherapy, TESE may be successful and pregnancy can be achieved. These are early and encouraging results but since there are so many types of chemotherapy agents used, large numbers of patients will be needed to give an individual patient an accurate assessment of his chances. In addition, the children will need to be followed carefully as there is no data as to their future health. Data that discusses naturally conceived offspring of post-chemotherapy men cannot be applied to this group as spermatogenesis in these men returned to good levels, unlike this study group who were more severely and permanently affected.

Spermatic granuloma in the ram: diagnosis by ultrasonography and semen characteristics.

Ultrasonographic appearance of the testis and epididymis, and seminal characteristics, with regard to localization of spermatic granuloma were studied. In rams with spermatic granuloma (n = 9), diagnosed by clinical or ultrasonographic examinations before histopathological confirmation, localization of each lesion was recorded. Epididymal granulomas, caput and cauda, were seen as anechoic or hyperechoic areas with a distinct margin with or without a hyperechoic capsule. Granulomas in the testis were microscopic and, therefore, could not be detected by ultrasonography. Enlargement in the mediastinum testis was detected in all rams when there were granulomas in the caput. Heterogeneous testis parenchyma invaded by numerous hyperechoic foci, representing testicular degeneration, was associated with granulomas both in the epididymis and testis. Ultrasonographic appearance of the lesions did not differ with regard to season. Seminal characteristics varied between rams. It was concluded that ultrasonographic evaluation may give valuable information in the diagnosis of sperm granuloma in the ram.

Testicular microlithiasis: US findings in six pediatric cases and literature review.

The aim of this article is to report on six pediatric cases of testicular microlithiasis (TM) and to review literature reports, in order to schedule US and/or other control examinations, particularly when concomitant focal or diffuse alterations of the testicular parenchymal structure are present, considering the possible association of TM with testicular tumors. Six patients (age range 4-12 years) underwent US examination for scrotal trauma (two cases) unilateral cryptorchidism (one case) follow-up after orchidopexy for bilateral cryptorchidism (one case), and varicocele (two cases). Five examinations were performed with high-frequency probes (10/13 MHz) and seven with 5/7.5-MHz frequency transducers. Follow-up US examinations were performed at different times depending on initial clinical indications, presence of underlying disease, and initial US findings. Two of the six patients underwent three US examinations, two patients underwent two US examinations, and the remaining two patients underwent only one US examination. The patients underwent a total of 12 US examinations. Microliths were bilateral in four patients and unilateral in two patients. In these two latter cases, the contralateral testis was, in one case, cryptorchid and could not be evaluated by US; in the other case it was small and hyperechogenic with orchidopexy sequelae. In three cases microliths were distributed throughout the testis. In the remaining three cases they were present in limited areas of parenchyma. As to the importance of microliths, it was defined as mild in three cases and moderate/severe in three cases. Intratubular testicular microlithiasis is a well-proved histological finding (biopsy or autopsy). More recent is the US demonstration of TM with consequent definition of its pattern: usually bilateral hyperechogenic multiple small foci without acoustic shadows with complete or partial extension to the parenchyma. Testicular microlithiasis is a rare finding. Moreover, the pediatric cases reported in the literature are very few. However, the use of high-frequency US transducers (10-13 MHz) has recently allowed an easier demonstration of this disease also in children. Of particular interest is the study of the still-debated association of microliths with other diseases such as neoplasms. Some aspects need further investigation, namely the real incidence of microliths in the healthy population, the incidence of tumors in patients with microliths, the differences between adults and children, and the different types of follow-up at different ages. In pediatric age, if TM represents an isolated sign, patients need non-invasive US follow-up until adult age. Only if TM is in association with focal lesions of testis parenchyma is it mandatory to perform biopsy or surgical treatment.

Intrasplenic autograft of testicular tissue in rats.

Intrasplenic heterotransplantation of infantile testis is a conventional method to produce testicular tumors in adult castrated rodents. To avoid possible immunological interference in the tumorigenic process in allografted testis, the parenchyma of testis of Wistar strain rats aged 7 weeks was injected into the spleen of the same rat after bilateral gonadectomy. In 17 of 20 animals testicular neoplasms, resembling gonadal stromal cell tumors in human, developed from the intrasplenic gonadal tissue in the 14th month following transplantation. This autografting technique is feasible to induce testicular neoplasms in granulosa cell tumor category in high incidence, and thus deserves further attention.

Nuclear lamin expression in normal testis and testicular germ cell tumours of adolescents and adults.

Nuclear A- and B-type lamins are differentially expressed in tissues, depending on the degree of cellular differentiation and proliferative status. By studying lamin expression in testis parenchyma and testicular germ cell tumours, further insight may be gained into the degree of cellular differentiation in normal testis and into the whole spectrum of differentiation lineages found in testicular germ cell tumours. Frozen tissue sections of normal testis and the different types of testicular germ cell tumours were immunostained with monoclonal antibodies to distinct lamin subtypes. Lamin reactivity was evaluated in relation to the lineage and degree of cellular differentiation and the reactivity patterns were compared with each other and with those in normal testis. In normal testis, both A- and B-type lamins were expressed in Sertoli, Leydig, and peritubular cells, while in spermatogonia only B-type lamins were found and spermatocytes showed weak reactivity with the A-type lamin antibodies. Carcinoma in situ was most often positive for both of the B-type lamins and negative for the A-type lamins (lamins A and C). In testicular germ cell tumours, B-type lamins were always expressed, while A-type lamins were differentially expressed. Differentiated non-seminomas were positive for both of the A-type lamins, whereas embryonal carcinomas were positive for lamin C and negative for lamin A. Seminomas were negative for both of the A-type lamins, with the exception of seminomas containing a Ras mutation. Spermatogonia and seminoma cells, which follow a differentiation pathway along the spermatogenic lineage and show characteristics of germ cells, do not express A-type lamins. Non-seminomas, showing embryonal or extraembryonal differentiation, express A-type lamins to varying degrees, distinguishing embryonal carcinoma cells from other non-seminomatous components. This may aid in the evaluation of the percentage of embryonal carcinoma in non-seminomatous testicular germ cell tumours as a prognostic parameter.

Unique expression patterns of H19 in human testicular cancers of different etiology.

The expression pattern of the imprinted human H19 gene was investigated in testicular cancers of different etiology, as well as in normal testicular parenchyma, parenchyma without germ cells, and adjacent to testicular germ cell tumors of adolescents and adults (TGCTs), using RNase protection analysis, mRNA in situ hybridization and reverse-transcription polymerase chain reaction. While different total expression levels were detected in spermatocytic seminomas, lymphomas, a Sertoli cell tumor and Leydig cell tumors, none showed a disturbance of monoallelic expression. Strikingly, the majority of invasive TGCTs revealed expression of both parental alleles. The total level of expression highly correlated with differentiation lineage and stage of maturation, similar to that as reported during early normal embryogenesis. Biallelic expression could also be determined specifically in testis parenchyma containing the preinvasive lesion of this cancer. We therefore conclude that within the adult testis, biallelic H19 expression is specific for TGCTs, and that the level of expression is dependent on differentiation lineage and maturation stage. This is in agreement with the proposed primordial germ cell-origin of this cancer, and might be related to retention of embryonic characteristics in TGCTs. In addition, our data argue against H19 being a tumor suppressor gene.

Aberrant platelet-derived growth factor alpha-receptor transcript as a diagnostic marker for early human germ cell tumors of the adult testis.

Testicular germ cell tumors are the most common form of cancer in young adult males. They result from a derangement of primordial germ cells, and they grow out from a noninvasive carcinoma-in-situ precursor. Since carcinoma in situ can readily be cured by low-dose irradiation, there is a great incentive for non- or minimally invasive methods for detection of carcinoma in situ. We have recently shown that human Tera-2 embryonal carcinoma cells, obtained from a nonseminomatous testicular germ cell tumor, show alternative splicing and alternative promoter use of the platelet-derived growth factor alpha-receptor gene, giving rise to a unique 1.5-kb transcript. In this study we have set up a reverse transcriptase-polymerase chain reaction strategy for characterization of the various transcripts for this receptor. Using this technique, we show that a panel of 18 seminomas and II nonseminomatous testicular germ cell tumors all express the 1.5-kb transcript. In addition, a panel of 27 samples of testis parenchyma with established carcinoma in situ were all found to be positive for the 1.5-kb transcript, while parenchyma lacking carcinoma in situ, placenta, and control semen were all negative. These data show that the 1.5-kb platelet-derived growth factor alpha-receptor transcript can be used as a highly selective marker for detection of early stages of human testicular germ cell tumors.

Quantification of apoptosis (programmed cell death) in mammalian testis by DNA-fragmentation ELISA

Apoptosis (programmed cell death) could contribute to fluctuations in sperm production and involution of testis in dependence on seasonal, genetic, environmental or individual factors. Investigations of such factors require a reliable quantitative examination of apoptotic processes. Therefore, a standardized procedure was developed for quantification of apoptosis in samples of testicular parenchyma in bull. This test is based on a highly sensitive DNA-fragmentation ELISA which was used originally for somatic cells in culture. Aliquots of testicular parenchyma were minced and homogenized by freezing/thawing and subsequent sonification at 4 degrees C. In comparison, aliquots were lysed in original buffer from the cell death detection ELISA-kit. Nucleosomes from the cell cytoplasm were obtained in supernatant of homogenate or lysate after centrifugation. The absorbance was linear over the range of sample concentrations from 5 to 20 microg testis equivalent/100 microl solution. Therefore, samples were standardized to a final concentration of 10 microg testis equivalent/100 microl. The recorded values were expressed in units per mg tissue (U/mg). The method was used to study testicular apoptotic processes in the guinea pig and roe deer. The results showed that apoptosis can be detected in testicular homogenate prepared from 0.01 mg testis parenchyma within 24 h after recovery of testes without significant variations. Detectable apoptosis levels showed differences among sexually active guinea pig (7.08 +/- 1.95 U/mg), roe deer (16.32 +/- 3.45 U/mg), and cattle (29.0 +/- 7.1 U/mg). This species-specificity suggests different cross reactivity of the monoclonal antibody used in the ELISA. A significantly higher amount of testicular apoptosis was detected in a population of guinea pigs with increased inbreeding coefficients (f = 0.785 - 0.998) than in outbred animals (11.41 +/- 3.50 U/mg and 7.08 +/- 1.95 U/mg, respectively). The inverse relationship of testicular apoptosis and proliferation in these two populations was significant (r = -0.531; P < 0.05). In conclusion, the relative simplicity and high sensitivity of this nonradioactive method provides a useful approach to investigate spermatogenesis under different conditions. Results in the guinea pig showed that apoptosis plays an important role in the regulation of gonadal efficiency.

NEW DIAGNOSTIC TECHNIQUES IN THE EVALUATION OF ANATOMIC ABNORMALITIES OF THE INFERTILE MALE

New diagnostic imaging modalities have taken on a major role in the diagnosis of disease entities related to male infertility. Ultrasonography, MR imaging, and new operative diagnostic maneuvers will continue to define anatomy, physiology, and pathology of the male reproductive system. When any disease process affects the male in the reproductive or prereproductive years, potential repercussions on subsequent male factor fertility should always be addressed in the treatment plans of such patients. Scrotal ultrasonography is extremely helpful in identification of abnormalities of the testis parenchyma, paratesticular structures, and blood flow in the region of the testes. TRUS has replaced the vasogram as the initial diagnostic test for evaluation of the prostate, ejaculatory duct, and seminal vesicles in the infertile male. It may also be used as an adjunct to treatment in these patients. MR imaging may become a useful adjunct to TRUS in defining male genital ductal anatomy prior to surgical exploration. Vasal exploration, including subjective vasal injection pressure, vasal fluid examination, and vasography, is an important diagnostic tool in the diagnosis and treatment of male genital disorders.

Duration of the cycle of the seminiferous epithelium and quantitative histology of the testis of the South American white-belly opossum (Didelphis albiventris), Marsupialia

The duration of the cycle of the seminiferous epithelium of the South American white-belly opossum, as obtained by autoradiography after intratesticular injection of tritiated thymidine, was estimated to be 17.3 +/- 0.1 days (mean +/- s.d.). Quantitative histological analysis was performed on testes from animals caught both in mating and non-mating periods of the annual reproductive cycle. Significant differences were found in the volumetric proportion of Leydig cells, but the spermatogenic yield remained constant throughout the year. The numerical ratio between type A spermatogonia and zygotene primary spermatocytes (1:12.0), as well as daily sperm production (4.8 x 10(6) sperm cells per g of testis parenchyma per day), were found to be lower than those reported in most eutherian mammals.

Dietary (n-3) Fatty Acids Alter Fatty Acid Composition and Prostaglandin Synthesis in Rat Testis

The objective of this study was to determine the efficacy of linolenic acid [18:3(n-3)], compared with the long-chain (n-3) fatty acids in fish oil, in suppressing arachidonic acid [20:4(n-6)] metabolism in rat testis. Six groups of rats were fed three levels of 18:3(n-3) or fish oil, and the fatty acid composition of testis parenchyma lipids and prostaglandin (PG) I2 synthesis by tunica were determined after 12 wk. Levels of docosapentaenoic acid [22:5(n-6)], the major 22-carbon fatty acid in rat testis lipids, were significantly depressed compared with the control by both linolenic acid and fish oil; however, testis weights were not affected significantly. Arachidonic acid levels also were depressed significantly in testis lipids by dietary (n-3) fatty acids, but the decreases were not as pronounced as those observed in other tissues. The synthesis of PGI2 was significantly reduced compared with the control by (n-3) fatty acid feeding, but there were no differences among the experimental groups. Both 18:3(n-3) and the longer-chain (n-3) fatty acids from fish oil reduce levels of 20:4(n-6) and 22:5(n-6) in testis lipids and the capacity of the tunica to synthesize PGI2, but these fatty acids seem to cause no defect in testicular development as indicated by weight.

The effect of dietary vitamin E and ß-carotene on oxidation processes in the rat testis

The effects of dietary vitamin E and beta-carotene were studied on enzymes involved in arachidonic acid metabolism and other related enzymes in the rat testis. Groups of rats were fed various soybean oil-based semi purified diets. Group 1 was fed a vitamin E-supplemented diet (+E - beta); Group 2 was fed a beta-carotene-supplemented diet (-E + beta); Group 3, the control group (-E - beta) was fed a vitamin E-deficient diet; and Group 4, the standard diet group (S), was fed vitamin E plus beta-carotene-standard diet. Soybean oxidized oil was added to the three diet groups - (+E - beta), (- E + beta) and (- E - beta), whereas the diet of S group contained non-oxidized oil. After 8 weeks rats were killed, blood and testis samples were collected for biochemical determinations. Vitamin E deficiency caused significant increase in testis thiobarbituric acid value and activities of testis NADPH oxidase, testis 15-lipoxygenase and in plasma pyruvate kinase. In contrast, significant decreases were observed in activity of testis prostaglandin synthetase, compared with antioxidant-supplemented diet groups. We also found a significant increase in 15-lipoxygenase activity in (- E + beta) diet group, compared with (- E - beta) diet group. Fatty acid analysis of testis parenchyma indicated decrease in palmitate (16:0) and arachidonate (20:4(n - 6)), and increase in oleate (18:1(n-6)) linoleate (18:2(n - 6)) and linolenate (18:3(n - 3)), when compared (-E - beta) diet group with vitamin E-supplemented diet groups. The results suggest that dietary vitamin E has a role in both enzymatic and non-enzymatic peroxidation of polyunsaturated fatty acids in the testis.