Degeneration Of Spermatogenic Cells Research Articles

Impacts of Acrylamide on testis and spermatozoa.

Acrylamide (ACR) is an industrial chemical used to produce polyacrylamide, a synthetic polymer with a wide range of applications. Depending on the dosage, its presence in occupational and environmental sources poses potential health risks to humans and animals. ACR can be formed in starchy foods cooked at high temperatures. Its effects on human sperm are not well understood. Animal studies indicate that ACR induces toxicity in the male reproductive system through oxidative stress mechanisms. Exposure to ACR alters the normal structure of testicular tubules, leading to congestion, interstitial edema, degeneration of spermatogenic cells, formation of abnormal spermatid giant cells, and necrosis and apoptosis. It also disrupts the balance of important biomarkers such as malondialdehyde, nitric oxide, superoxide dismutase, catalase, and glutathione. ACR has a negative impact on mitochondrial function, antioxidant enzymes, ATP production, and sperm membrane integrity, resulting in decreased sperm quality. Furthermore, it interferes with the expression of steroidogenic genes associated with testosterone biosynthesis. This review explores the detrimental effects of ACR on sperm and testicular function and discusses the potential role of antioxidants in mitigating the adverse effects of ACR on male reproduction.

Salvia officinalis restores semen quality and testicular functionality in cadmium-intoxicated male rats

The present study investigated the potential ability of Salvia officinalis, one of the oldest medicinal plants, to protect male rats against cadmium reproductive toxicity. Twenty-eight healthy male rats were randomly allocated into four groups (n = 7); control, Salvia-extract treated group, cadmium treated group and a group treated with both Cd and Salvia. Administration of cadmium reduced the relative testis to body weight and significantly affected sperm parameters by decreasing motility, viability, count and increasing morphological aberrations. Comet assay was used to detect DNA fragmentation in sperms of the rats exposed to Cd. Serum levels of testosterone T, follicle stimulating hormone FSH, and luteinizing hormone LH were significantly decreased. The biochemical analysis of testicular tissue showed a significant rise in Malondialdehyde MDA level coupled with a decrease in the activity of antioxidant enzymes (superoxide dismutase SOD, glutathione peroxidase GPx and catalase CAT). The histological examination of testis sections after Cd administration revealed severe degeneration of spermatogenic cells. Seminiferous tubules were filled with homogenous eosinophilic fluid associated with atrophy of other seminiferous tubules. Co-treatment with the Salvia officinalis extract restored the oxidative enzymes activities and decreased the formation of lipid peroxidation byproduct, which in turn ameliorated the effect of Cd on sperm parameters, DNA damage and testis histopathology. Taken together, it can be concluded that the synergistic antioxidant and radical savaging activities of Salvia officinalis prevented the effect of Cd on semen quality, sperm DNA damage, along with the oxidative stress and histological abnormalities in the testis tissues.

Nigella sativa Oil Alleviates Mouse Testis and Sperm Abnormalities Induced by BPA Potentially through Redox Homeostasis.

Significant evidence indicates that endocrine disrupted bisphenol A (BPA) seriously endangers human health. In males, BPA affects testis architecture and sperm quality, and ultimately reduces fertility. This study explored the therapeutic potential of Nigella sativa (NS) seed extract on testis and sperm abnormalities in BPA-exposed mice and characterized the underlying mechanism. Forty male Swiss albino mice (5.5 weeks old, N = 8 per group) were randomly divided into five groups: Group I, normal control, Group II, vehicle control (sterile corn oil); Group III, NS-exposed (oral 200 mg/kg); Group IV, BPA-exposed (oral 400 μg/kg body weight); Group V, BPA + NS-exposed mice. Animals were treated for 6 weeks and sacrificed for biochemical and histological examination. The results indicated that BPA exposure results in significant testis and sperm abnormalities. Specifically, BPA promoted a marked reduction in the body and testis compared with the control group. Histopathological findings showed that BPA caused a widespread degeneration of spermatogenic cells of the seminiferous epithelium, decreased sperm counts and motility, and augmented sperm abnormalities, and whereas little alteration to sperm DNA was observed. In addition, BPA increased the levels of the lipid peroxidation marker, malondialdehyde (MDA), and reduced the levels of the antioxidant marker, reducing glutathione (GSH). Treatment with NS oil extract during BPA exposure significantly alleviated testis and sperm abnormalities, reduced MDA levels, and enhanced GSH levels. The results demonstrate that NS oil protects mice against BPA-induced sperm and testis abnormalities, likely by suppressing levels of the oxidative stress marker, MDA, and enhancing the levels of the antioxidant marker, GSH.

Effects of ethanol on testis: A histopathological study in adult rats

Chronic alcohol consumption leads to many dysfunctions in the reproductive system. The pathological changes in the testis is depends on the level and duration of alcohol consumption. The purpose of the present study was to find out the histopathological changes in the testis in chronic ethanol exposure. Adult rats were divided into control (C) and ethanol treated (E) groups eight animal each. The rats in group E were exposed to ethanol 1gm/kg body weight for three months after due approval from the institutional animal ethics committee. After the exposure period, testes were processed for light microscopic examination. Ethanol treated rats showed loss of normal distribution of spermatogenic cells in the seminiferous tubules and few fragmented sperms in the lumen. Most of the tubules showed that the germ layers were detached from the basal lamina. It has been suggested that ethanol induced the degeneration of spermatogenic cells in the testis.

Formaldehyde and anti-fertility: correlation between testicular cytoarchitecture and semen analysis

The anti-fertility effect of formaldehyde was investigated on the testicular cytoarchitecture and semen of Sprague-Dawley rats exposed to formaldehyde by inhalation. Thirty adult male rats were randomly selected into three (3) groups of ten (10) rats each. The treatment group 2 and group 3 were exposed to 40% stock concentration of formaldehyde for 1 min/m2 and 2 min/m2 respectively daily for four (4) weeks of experimental period. The control group (group 1) was allowed free access to natural air throughout the experimental period. Testis was dissected out following cervical dislocation and fixed in Bouins fluid for histological processing. Caudal Epididymis was also dissected out and suspended in 1ml of Hams F- 10 solution for estimation of sperm concentration and motility. Semen analysis revealed a significant reduction in sperm concentration and sperm motility in the treated groups. Histological alterations in the seminiferous tubule and degeneration of spermatogenic cells were observed in the treated groups compared with the control. Reduction in sperm concentration and motility and histological alteration of the testes in the treated rats showed that formaldehyde might have toxicity on the reproductive organ.

Ameliorating Effect of Pineapple Juice on the Obesity-Induced Testicular Impairment in Male Wistar Rat.

<b>Background and Objective:</b> Obesity exerts negative influences on male reproductive capacity via changing the molecular and physical structure of male germ cells. This study was conducted to evaluate the mitigating effects of raw juice of pineapple on obesity-associated testicular impairment in male Wistar rats. <b>Materials and Methods:</b> Rats included the control group (G<sub>I</sub>, n = 6) who received a Normal Diet (ND) and the obese group (G<sub>II</sub>, n = 18) who received a High-Fat Diet (HFD). Obese rats (G<sub>II</sub>) were subdivided into 3 groups (6 rats each): G<sub>II</sub> represents the untreated obesity group that continued to receive HFD with plain Drinking Water (DW), G<sub>III</sub> received ND along with raw juice (15% v/v) in DW and G<sub>IV</sub> continued to receive HFD with raw juice (15% v/v) in DW. Rats were sacrificed at the end of the trial and testis was processed for histopathology and immunohistochemistry. <b>Results:</b> Testis from obese rats revealed a significant increment in spermatogenic cell degeneration, pro-inflammatory Nuclear factor of kappa B (NF-κB) and pro-apoptotic Caspase-3 immunoreactivities. Yet, Proliferating Cell Nuclear Antigen (PCNA) displayed poor immunoreactivity in obese rats' testis relative to controls. Administration of raw juice of pineapple to obese rats significantly reduced degeneration of spermatogenic cells, NF-κB and Caspase-3 immunoreactivities. Additionally, treatment with the juice significantly increased immunoreactivity to PCNA in obese rats. These ameliorating effects were more obvious in rats who received juice along with ND (G<sub>III</sub>) than in those who received it along with HFD (G<sub>IV</sub>). <b>Conclusion:</b> Treatment of obese rats with pineapple juice restored testicular homeostasis, indicating its potential validity to overcome obesity-induced male fertility disorders.

Vitamin D: An effective way to combat methotrexate-induced testis injury

Methotrexate (MTX) is a frequently used anticancer drug in the treatment of several diseases. However, MTX therapy causes significant cytotoxicities in testicular tissue. In this experimental study, the therapeutic utility of vitamin D (VD) on MTX induced testicular injury was investigated. Twenty-eight Wistar rats were randomly divided into four equal groups; Control, VD, MTX, and MTX+VD. Following the treatment, the rats were sacrificed and testicular tissues were removed. Testicular tissues were analyzed for routine histopathology and apoptosis. The activities of glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) were evaluated by enzyme-linked immunosorbent assay and malondialdehyde (MDA) levels were measured spectrophotometrically. MTX-treatment group exhibited degeneration of spermatogenic cells, desquamation of the epithelial cells into the lumen of the tubules, lack of spermatozoa in tubule lumen, edema at interstitial area, a statistically significant decrease in both height and diameter of the tubules (p < 0.05). These values were also concordant with the Johnsen’s testicular biopsy score (JTBS). In addition, a significantly increased caspase-3 immunoreactivity was observed. Serum and testicular tissue SOD, and GSH-Px enzyme activities were found to be decreased while MDA increased in the MTX group compared to control group (p < 0.05). In the MTX + VD group, the histological injury was reduced, the caspase-3 positivity and MDA level decreased whereas activities of SOD, and GP-x enzymes were significantly increased compared to those in MTX group (p < 0.05). VD supplement may have a therapeutic utility in reducing the MTX-induced cytotoxicities in testicular tissue.

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BACKGROUND: The use of fruits as natural remedies to mitigate cellular and tissue induced alterations caused by exogenous toxins like alcohol have been widely documented, and the ethnopharmacological potentials of the Carica papaya have also been reported. AIM AND OBJECTIVES: The study aims to investigate if ripe fruit carica papaya administration attenuates testicular connective tissue alterations in experimental alcohol toxicity model. MATERIALS AND METHODS: Thirty (30) animals weighing between 150 to 220 g were used for this study, divided into 6 groups as follows; group 1 received distilled water 2 ml per kilogram body weight, group 2 received 40 % ethanol 5 ml per kilogram body weight, group 3 received 40 % ethanol 5 ml + clomiphene citrate 50 mg per kilogram body weight, groups 4, 5 and 6 received 40 % ethanol 5 ml + 500, 1000 and 1500 mg C. papaya per kilogram body weight respectively. Rats were weighed and thereafter sacrificed by anaesthetizing with chloroform, thoraco-abdominal wall dissected to access the heart and the testes. Harvested testes were fixed and sent to the laboratory for processing and histological analysis. RESULTS: Result of histological analysis showed ethanol treatment induced testicular atrophy, spermatogenic cell degeneration, interstitial tissue vacuolations, connective tissue disruptions, conditions which were ameliorated by C. papaya. This ameliorative potential of C. papaya appeared to be effective and dose dependent. CONCLUSION: While it is attributable that C. papaya may confer protective capabilities against ethanol induced testicular connective tissue damages, this study provides evidence that moderate intake of C. papaya ameliorated injuries induced by ethanol to the testicular connective tissue of rats with a mechanism believed to be antioxidant mediated.

Ameliorative effect of curcumin on fluoxetine-induced reproductive toxicity and oxidative stress in male albino rats

Fluoxetine is a selective serotonin reuptake inhibitor used to treat depression and mood disorders. Curcumin, the major active ingredient of turmeric (Curcuma longa), showed many pharmacological effects and is known for its potent antioxidant capacity. The present work aims to evaluate the possible ameliorative effect of curcumin on fluoxetine-induced reproductive toxicity and oxidative stress in albino rats. Histological examination of testis of fluoxetine-treated rats revealed degeneration of spermatogenic cells, congestion of blood vessels and destruction of Leydig cells. In addition, speramatogenesis was inhibited as indicated by the decrease of the number of different spermatogenic cells. The diameters of the seminiferous tubules and heights of their germinal epithelium were significantly reduced. Moreover, significant higher numbers of Bax-positive Leydig cells were recorded. Testosterone, luteinizing hormone (LH) and glutathione (GSH) were decreased while malondialdehyde were increased in sera of fluoxetine-treated animals. Treating animals with fluoxetine followed by curcumin revealed an improvement in the histological changes observed in animals treated with fluoxetine. Moreover, curcumin treatment leads to decrease in the number of Bax-positive cells, increase in testosterone, LH, GSH, and decrease of lipid peroxidation. According to the present results, it can be concluded that combined treatment with fluoxetine and curcumin can improve the testicular abnormalities induced by fluoxetine. This effect of curcumin may be attributed to its antioxidant properties.

Accumulated HSV1-TK Proteins Interfere with Spermatogenesis through a Disruption of the Integrity of Sertoli-Germ Cell Junctions

Transgenic rats show spermatid-specific ectopic expression of the reporter gene, herpes simplex virus type1 thymidine kinase (HSV1-TK), in the testes and have demonstrated male infertility. However, the disruption of spermatogenesis and the underlying molecular mechanisms in these transgenic animals have not been well clarified. In this study, light and electron microscopic observations were performed to characterize the morphological changes in the testes. To explore the molecular mechanisms of male infertility in the HSV1-TK transgenic rat, cDNA microarray and quantitative real-time PCR analyses were performed. The seminiferous tubules of 3-month-old transgenic rats showed morphological alterations including seminiferous epithelial sloughing, vacuolization, and degeneration of spermatogenic cells, suggesting a failure of Sertoli-germ cell interaction. Components of the epididymal lumen from transgenic rats included abnormal spermatozoa, degenerating round spermatids and abnormal elongated spermatids indicating an appearance of direct impairment of spermiogenesis. cDNA microarray and real-time PCRanalyses revealed significant changes (P<0.05) in the gene expression level in six genes, testin, versican, mamdc1, fgf7, ostf1 and cnot7. Among them, testin drew most of our attention, since the testin gene is a sensitive marker for disruption of Sertoli-germ cell adhesion. Thus, our results suggest that the accumulation of HSV1-TK in the spermatids not only directly interferes with spermiogenesis but also disrupts spermatogenesis through a disruption of Sertoli-germ cell adhesions. It is important to explore the testicular actions of the HSV1-TK protein in transgenic experimental models and thereby gain clues to find an appropriate treatment for HSV-infected patients exhibiting human male infertility, as has been recently observed.

Effect of selenium on carbimazole-induced testicular damage and oxidative stress in albino rats

Carbimazole is an antithyroid drug used in treatment of hyperthyroidism. The present investigation studied the effect of carbimazole on testicular activity in albino rats and the ameliorative role of selenium. Treating rats with carbimazole (1.35 mg/kg b.w) daily for 8 weeks caused reduction in the body and testes weight. Moreover, the diameters of the seminiferous tubules and heights of their germinal epithelium were significantly reduced. Testes of treated rats showed many histological alterations included congestion of blood vessels, hemorrhage, degeneration of interstitial tissue and degeneration of spermatogenic cells with apoptosis and necrosis. Histochemical results revealed reduction in polysaccharides, total proteins and nucleic acids contents in testicular tissue. In addition, the level of testosterone, luteinizing hormone (LH), T 3, T 4 and thyroid stimulating hormone (TSH) was significantly decreased in sera of treated animals. Moreover, a high lipid peroxidation with a decrease in the enzymatic antioxidant status, superoxide dismutase (SOD) and catalase (CAT) was recorded in testes homogenate. Treating animals with carbimazole and selenium showed an improvement in the histological structure as well as histochemical components of the testis with an increase in the number of spermatogenic cells. There was an increase in testosterone, LH, T 3, T 4 and TSH levels. Moreover, administration of selenium led to decrease in malondialdehyde and increase in catalase and superoxide dismutase activities. It is suggested that the curative effect of selenium against testicular damage induced by carbimazole may be due to its antioxidant properties.

Subchronic supplementation of lithium carbonate induces reproductive system toxicity in male rat

Lithium is frequently used as an effective drug for the treatment of several psychiatric disorders in human. This alkali element and its salt, at its higher doses, may lead to various side effects or has several toxic effects after prolonged therapeutic use. To test this hypothesis, the present study was designed to investigate the adverse effect of subchronic exposure of lithium carbonate on reproductive organs of male rat. Rats were exposed to lithium carbonate at doses of 500, 800, 1100 mg/kg of diet for 90 days. The weight of reproductive organs, histology of testis, epididymis, seminal vesicle, prostate, testicular interstitial fluid volume (IFV), testosterone level, sperm morphology and fertility index were analyzed. Treatment with higher doses of lithium carbonate (i.e. 800, 1100 mg/kg diet) significantly reduced testes, epididymis and accessory sex organs weights, whereas, lower dose (500 mg/kg diet) did not show any untoward effect. Similarly, the sperm number from cauda epididymis and daily sperm production was significantly decreased with higher doses of lithium carbonate. The serum testosterone levels and IFVs were also reduced significantly. Seminal vesicle and prostate secretions were completely blocked and spermatozoa were not seen in the lumen of epididymis and vas deference. Histological studies have revealed that lithium carbonate (1100 mg/kg) caused degeneration of spermatogenic cells and vacuolization of sertoli cells cytoplasm in the testis. The sperm transit rate and production of abnormal spermatozoa were significantly ( P<0.01) increased. When the lithium carbonate-treated males were mated with normal cyclic females, the fertility index declined to 50% even after 30 days of withdrawal of lithium carbonate treatment. These results clearly suggest that subchronic exposure of lithium carbonate promote reproductive system toxicity and reduces fertility of male rats.

Impaired Spermatogenic Ability of Testicular Germ Cells in Mice Deficient in the LIM-Kinase 2 Gene

LIM-Kinase (LIMK), including LIMK1 and LIMK2, is the only known catalytic protein among LIM-family molecules. It is well known that LIMK phosphorylates and inactivates cofilin, an actin-depolymerizing factor regulating actin reorganization, while in vivo functions have remained to be elucidated. In the present study, we generated Limk2 gene-deficient mice in which three LIMK2 isoforms were disrupted in a Cre-mediated fashion. Impaired cofilin phosphorylation was clearly observed in Limk2−/− fibroblasts stimulated with bradykinin or lysophosphatidic acid, thereby suggesting that Cdc42 or Rho-dependent LIMK activation did not occur. However, Limk2−/− mice did not exhibit embryonic lethality or any phenotypic abnormalities in postnatal growth and development, except for spermatogenesis in the testis. The testes of Limk2−/− mice were smaller in size and partial degeneration of spermatogenic cells in the seminiferous tubules was apparent in association with increased apoptosis. In addition, the viability of Limk2−/− spermatogenic cells, when cultured under stressed conditions, was diminished. Furthermore, the potential for germ cells to differentiate in a regenerative state was severely impaired in Limk2−/− testis. Experimental hyperthermia induced impairment of ADF/cofilin phosphorylation and the formation of intranuclear cofilin inclusions in mutant germ cells. Based on these findings, we propose that LIMK2, especially the testis-specific isoform tLIMK2, plays an important role in proper progression of spermatogenesis by regulation of cofilin activity and/or localization in germ cells.

Transient disruption of spermatogenesis by deregulated expression of neurturin in testis

Two related ligands, glial cell line-derived neurotrophic factor (GDNF) and neurturin (NRTN), are expressed by Sertoli cells, but their cognate ligand-binding co-receptors, GDNF family receptor α1 and α2, are displayed by different germ cells suggesting different targets for the ligands. GDNF regulates cell fate decision of undifferentiated spermatogonia ‘Science 287 (2000) 1489’. The role of NRTN was now approached by targeted overexpression in mouse testis. Between 3 and 5 weeks of age, transient degeneration of spermatogenic cells was observed in approximately 20% of all five transgenic lines generated. Spermatids and pachytene spermatocytes underwent segmental degeneration, if the rete testis was undilated. When it was dilated, the spermatids and spermatocytes were more generally depleted. After 5 weeks of age, spermatogenic defects were no more observed and the NRTN overexpressing mice were fertile. The data suggest that NRTN might regulate survival and differentiation of spermatocytes and spermatids, but the low penetrance indicates that either the transgene expression has not been high enough or NRTN is not as essential as GDNF for spermatogenesis.

Spermatogenic Cell Apoptosis Induced by Mitomycin C in the Mouse Testis

Spermatogenic cell degeneration in the mature mammalian testis occurs both spontaneously during normal spermatogenesis and in response to cytotoxic agents. Mitomycin C (MC) is an antibiotic that affects DNA synthesis. In the present study, we examined the induction of mouse spermatogenic cell apoptosis by MC, using TdT-mediated dUTP–biotin nick end labeling (TUNEL) to detect high levels of DNA fragmentation in situ,transmission electron microscopy (TEM) to observe nuclear chromatin condensation, and molecular methods to detect DNA ladders. This study shows that in the testis of MC-treated mice: (i) apoptotic cell death with fragmentation of nuclear DNA is induced by MC dose-dependently, (ii) apoptotic cell death is most commonly found in the spermatogonia and less frequently in spermatocytes, and (iii) apoptotic cell death induced by MC is not specific for the seminiferous stage of the tubules. The present study suggests that the spermatogenic cell apoptosis induced by MC might be involved in its testicular toxicity.

Seasonal changes in spermatogenic cell degeneration in the seminiferous epithelium of adult Japanese macaques (Macaca fuscata fuscata)

The degenerating pattern of spermatogenic cells in the seminiferous tubule of Japanese macaques was studied to clarify a relationship between seasonal changes of reproductive performances and cytological findings in the Japanese macaque. For light microscopy, testis samples were obtained from five adult animals by biopsy in April (nonmating season) and October (mating season). For electron microscopy, specimens from four additional macaques were used. Degenerating cells were found in all steps of spermatogenesis. In stages I to V of the cycle of the seminiferous epithelium, morphologically atypical pachytene spermatocytes were observed in 14.7 and 10.0% of the cells in the nonmating and mating seasons, respectively, although the difference in percentage was not significant. Mature spermatids with atypical features in those stages occupied 59.6% of the cells in the nonmating season, which significantly decreased to 34.1% in the mating season. These results imply that the seasonal change of sperm production is related, at least in part, to the process of degeneration of the spermatogenic cells in this species.

Testicular effects of di-n-butyl phthalate (DBP): Biochemical and histopathological alterations

Di-n-butyl phthalate (DBP) was administered to young male rats by gavage at the doses of 250, 500 and 1,000 mg/kg body weight/day for 15 days. A significant decrease in testes weight was observed at 500 and 1,000 mg/kg doses of DBP. Histopathological examination revealed marked degeneration of seminiferous tubules. The activities of testicular enzymes associated with postmeiotic spermatogenic cells, such as sorbitol dehydrogenase and acid phosphatase, were decreased significantly, while that of lactate dehydrogenase was significantly increased, coincident with degeneration of spermatogenic cells. The activities of enzymes associated with premeiotic spermatogenic cells, Sertoli cells or interstitial cells, beta-glucuronidase, gamma-glutamyl transpeptidase and glucose-6-phosphate dehydrogenase were significantly increased. Thus the alterations in activity of these testicular cell specific enzymes suggest that DBP exposure during early life could affect the testicular functions.

Characterization of cis-platinum-induced Sertoli cell dysfunction in rodents

The present study examined the effects of dosage and frequency of cis-platinum administration on various aspects of Sertoli cell function and its correlation with the status of spermatogenesis in rats 1 and 9 weeks after the initial drug administration. Adult male Sprague-Dawley rats were administered cis-platinum (10 mg/kg) intraperitoneally as a single dose or as five daily doses of 2 mg/kg. Electron microscopic observation of testicular tissues fixed in the presence of lanthanum revealed that cis-platinum administration resulted in leakage of the Sertoli cell tight junctions. This occurred as early as 24 hr after the five daily injections, and persisted at least 40 days. Testicular androgen-binding protein (ABP) content was not significantly affected by either treatment regimen after 1 or 9 weeks of recovery. On the other hand, serum ABP values were significantly elevated after 9 weeks of recovery. In addition, the increased sodium and decreased potassium concentrations in seminiferous tubular fluid noted in cis-platinum-treated animals were also indicative of abnormal Sertoli cell secretory function. Degeneration of spermatogenic cells was noted as early as 5 days after the last drug administration; and partial restoration of spermatogenesis was noted after 40 days of recovery. We conclude that in rats both morphological and biochemical properties of Sertoli cells are affected by cis-platinum administration. These changes in Sertoli cell function may be responsible for the cis-platinum-induced impairment of spermatogenesis in these animals.

Interferon expression in the testes of transgenic mice leads to sterility.

A plasmid containing the mouse interferon-alpha 1 gene under control of the mouse metallothionein-I promoter was used for the construction of transgenic mice. Four transgenic mice (two males and two females) were obtained containing 1 to over 10 copies of the introduced DNA. Both males appeared to be sterile. One of the female mice founded a transgenic strain in which the foreign DNA was transmitted to her offspring in a Mendelian fashion. In this strain most male animals are sterile or turn sterile with time. Northern blot analysis of several tissues of these animals shows that expression of the introduced interferon gene occurs only in the testis. In some of the animals biologically active interferon could also be detected in testes homogenates. Histological examination of testis tissue shows an ongoing degeneration of spermatogenic cells leading to calcium deposits and complete atrophy of the seminiferous tubules.

Differential effects of (+)- and (-)-gossypol enantiomers on LDH-C4 activity of hamster spermatogenic epithelium in vitro.

Tubular fragments (spermatogenic epithelium) from immature hamsters were isolated and cultured with low doses of (+)- and (-)-gossypol enantiomers. The activity of lactate dehydrogenase isoenzyme LDH-C4 was estimated as a marker for spermatogenic cell development and alpha-ketoisovalerate was used as the substrate. In the absence of gossypol, the specific activity of LDH-C4 in the tubular fragments was increased 40% during incubation for 48 h. This developmental increase was suppressed by gossypol. The specific activity of LDH-C4 in the tubular fragments was lowered by gossypol, after 48 h of culture in the presence of low doses of racemic gossypol (1-4 microM) and 1% fetal calf serum. In this in-vitro system the (-)-enantiomer but not the (+)-enantiomer of gossypol affected the LDH-C4 activity. This is in agreement with other reports showing that only the (-)-enantiomer induces infertility. The observed action of gossypol on LDH-C4 activity in the tubular fragments may reflect gossypol-induced degeneration of spermatogenic cells. The present in-vitro system can be used to estimate the actions of gossypol derivatives, other investigational antifertility agents, and toxic agents on the spermatogenic epithelium.