Phycobiliproteins Ameliorate Gonadal Toxicity in Male Mice Treated with Cyclophosphamide

Cyclophosphamide (CP)—which is used to treat autoimmune diseases and cancer—is related to gonadotoxicity attributed to oxidative stress. As phycobiliproteins (PBPs) are strong antioxidants that are unexplored as protective agents against male gonadotoxicity, our work aimed to investigate the effects of PBP crude extract on testicular damage and sperm parameter alterations caused by CP in mice. Three doses of PBP (50, 100, and 200 mg/kg) were tested in the experimental groups (n = 8 per group), administered concomitantly with 100 mg/kg CP. After 42 days receiving PBP daily and CP weekly, body and relative testicular weights, serum testosterone levels, testicular lipoperoxidation and antioxidant enzyme activity levels, and testicular histology and sperm parameter alterations were assessed. The results showed that PBP crude extract at 200 mg/kg prevented testosterone serum reduction, body weight loss, lipoperoxidation and enzyme activity increments, and sperm parameter alterations and partially ameliorated relative testicular weight reductions and histological damage in CP-treated mice. In conclusion, we showed that PBP crude extract (200 mg/kg) mitigated oxidative damage in the testes and ameliorated alterations in sperm parameters in mice treated with CP (100 mg/kg); therefore, PBP extract could be considered as a potential protective agent against CP toxicity.     

Semen quality and reproductive sex hormone levels in Peruvian pesticide sprayers

To determine the association between occupational pesticide exposure and semen quality among sprayers using organophosphate (OPs) pesticides, 31 pesticide sprayers and 80 men who were not exposed were studied. Semen and blood samples were obtained one day after last pesticide application. Semen samples were analyzed for sperm concentration, percentage of sperm motility, percentage of normal morphology, and fructose and zinc concentrations. Blood samples were analyzed for sex hormones. Pesticide sprayers had significantly reduced age-adjusted seminal volume, percentage of motility, percentage of sperm with normal morphology, serum luteinizing hormone, serum testosterone levels, and seminal zinc concentration (a marker of prostate function), as well as significantly increased time of liquefaction, seminal pH, percentage of immature sperm morphology, and leukocyte concentration. These findings provide further evidence that occupational exposures to OP pesticides adversely affect semen quality and sex hormones.     

Sustained azoospermia in squirrel monkey, Saimiri sciureus, resulting from a single intratesticular glycerol injection

Previous studies in rats had shown that a single intratesticular injection of glycerol resulted in long-term suppression of spermatogenesis without marked alterations in hormone levels. Studies were undertaken to determine the effect of similar treatment in squirrel monkeys (Saimiri sciureus). Ten monkeys received an intratesticular injection of saline (controls) and ten of glycerol solution (treated). Semen and blood samples were obtained on a weekly or bi-weekly basis one month prior to, during the 8 months following and at 22 months after the injection. Sperm numbers in the semen samples of controls remained at 160-435 x 10(6) per ml throughout the experiment. Sperm numbers in treated animals declined to near zero within two months and remained at zero. Serum testosterone and progesterone levels were not significantly different between control and treated animals. Serum LH and FSH levels were not significantly different between control and treated animals except during months 6-8 after the injection, when levels in the treated were higher. At termination (22 months), the weights and sperm contents of epididymides of the glycerol-treated animals were highly significantly reduced. Steroidogenesis (based on amounts and kinds of steroids formed from 14C-progesterone) by testicular tissue was not altered by the glycerol treatment when measured on a per testis basis. This is the first evidence that a single intratesticular injection of glycerol results in long-term suppression of spermatogenesis in primates, without altering testicular steroidogenesis and serum hormone levels.     

Effects of cyproterone acetate with combination of testosterone enanthate on seminal characteristics, androgenicity and clinical chemistry in langur monkey

Daily oral administration of 1 mg/kg b.w. of cyproterone acetate and simultaneously administered testosterone enanthate (2 mg/kg b.w./15 days; i.m.) to adult male langur monkeys over a period of 90 days caused a gradual decrease in the count (to azoospermia) and motility of spermatozoa, concurrently with an increase in the percentage of non-motile as well as abnormal and immature sperm. Semen weight, volume, seminal fluid volume and circulating testosterone levels decreased nonsignificantly. Semen pH, libido and body weight remained unimpaired. The levels of SGOT, SGPT, serum alkaline phosphatase, LDH, bilirubin, Na⁺, K⁺ and hematological values did not alter significantly. All the changes were reversible. The results indicate that the combination regimen seems to affect the fertility in two ways, i.e. by inhibiting spermatogenesis in the testis and maturation process in the epididymis without altering the androgenicity.     

Experience with a potent LH-RH agonist, buserelin, alone and in combination with testosterone for antispermatogenic activity, reversibility and toxicity in langur monkey

Chronic intermittent treatment of LH-RH superagonist Buserelin alone or in combination with testosterone enanthate were given to adult male langurs for 90 days to evaluate antispermatogenic activity of alone and combination therapy, maintenance of normal androgenicity, possible toxic effects of agonist treatment, related side effects of testosterone supplementation and complete reversibility of the procedure. A gradual decrease in sperm count was recorded in both treatment groups, along with reduced motility and vitality of the spermatozoa. In the combination group, oligospermia was achieved in 4 out of 5 animals, whereas, only 2 animals became oligospermic in the agonist alone group. Significant decrease in serum testosterone levels along with impaired libido and other testosterone withdrawal symptoms were observed in the Buserelin alone group, conversely normal testosterone levels and libido were observed in the combination group. An elevation in haematological variables and serum total protein concomitant with a slight gain in body weight of the animals were recorded in the combination group; these changes were not encountered in the agonist alone group. Reversibility of all the altered parameters to control range was observed in both treatment groups following 75 to 90 days of treatment withdrawal.     

Effect of Tripterigium wilfordii Hook. f. on the fertility of rats

Studies were undertaken to assess the effect of the total glycosides extracted from Tripterigium wilfordii Hook. f. (GTW), a ready-made Chinese herb medicine, on the fertility of both male and female rats. In male rats, GTW was given by gastric gavage at a dose of 10 mg/kg per day, 6 days a week for 8 weeks. All the treated animals became infertile. The body weight growth was normal and the mating behavior was present. There was a drastic decrease in the viability of the epididymal spermatozoa, while the decrease in the sperm density, though significant, was far less marked. Seminiferous tubular damage was minimal and no perceptible change was observed in the Leydig and the Sertoli cells. All other parameters examined, including the serum testosterone level and the histology of various organs, were normal. In female rats, GTW given orally at a dose of 50 mg/kg per day on days 1-4 or 7-9 of pregnancy did not significantly affect the fertility. It is thus concluded that non-toxic dose of GTW can cause infertility in male rats, the mechanism of which may involve and interference in the function of the epididymal and/or testicular spermatozoa; in female rats, the dose regimens employed do not have significant anti-implantation or early-pregnancy termination effect.     

Reproductive toxicity of low-level lead exposure in men

Parameters of semen quality, seminal plasma indicators of secretory function of the prostate and seminal vesicles, sex hormones in serum, and biomarkers of lead, cadmium, copper, zinc, and selenium body burden were measured in 240 Croatian men 19-52 years of age. The subjects had no occupational exposure to metals and no known other reasons suspected of influencing male reproductive function or metal metabolism. After adjusting for age, smoking, alcohol, blood cadmium, and serum copper, zinc, and selenium by multiple regression, significant (P<0.05) associations of blood lead (BPb), delta-aminolevulinic acid dehydratase (ALAD), and/or erythrocyte protoporphyrin (EP) with reproductive parameters indicated a lead-related increase in immature sperm concentration, in percentages of pathologic sperm, wide sperm, round sperm, and short sperm, in serum levels of testosterone and estradiol, and a decrease in seminal plasma zinc and in serum prolactin. These reproductive effects were observed at low-level lead exposure (BPb median 49 microg/L, range 11-149 microg/L in the 240 subjects) common for general populations worldwide. The observed significant synergistic effect of BPb and blood cadmium on increasing serum testosterone, and additive effect of a decrease in serum selenium on increasing serum testosterone, may have implications on the initiation and development of prostate cancer because testosterone augments the progress of prostate cancer in its early stages.     

阿维菌素亚急性染毒对大鼠肝脏和血清氧化应激指标的影响

目的 通过动物试验观察阿维菌素的亚急性毒性,从氧化性损伤角度探讨其毒作用机制,为接触阿维菌素的职业人群的疾病防护提供依据。 方法 将健康Wistar大鼠随机分为3组,每组10只,雌雄各半,分别为高剂量组(1/4 LD50)、低剂量组(1/8 LD50)和阴性对照组,采用经口灌胃方式连续染毒30 d。每周称量动物体重,实验结束后腹腔注射戊巴比妥钠麻醉动物,腹主动脉采血,检测血清MDA含量及GSH-Px、SOD活性;取动物肝、脾、肾、睾丸(或卵巢)称重,计算脏体比,组织用10%甲醛溶液固定,用于病理组织学检查。 结果 染毒后,阿维菌素高、低剂量染毒组与对照组相比,大鼠体重的增长幅度均呈现出降低趋势,实验结束时,三组雌性大鼠体重差值差异有统计学意义(F=102.85,P < 0.05);高剂量染毒组雌性大鼠的体重低于阴性对照组(t=3.235,P < 0.05);雌性大鼠的脑体比、肝体比、肾体比在三组间比较,差异有统计学意义(F=22.34、93.15、60.77,P均< 0.05);雌性高剂量组与对照组的脑、肝、肾体比差异,雌性低剂量组与对照组肝体比差异,雌性高剂量组与低剂量组脑体比的差异均有统计学意义(t=13.69、20.14、16.20、8.91、8.36,P均< 0.05)。大鼠血清MDA含量及GSH-Px、SOD活性在三组间比较,差异均有统计学意义(F=57.48、120.62、30.45,P均< 0.05)。与对照组相比,阿维菌素组大鼠MDA含量显著增加,GSH-Px、SOD活性显著降低(P < 0.05)。病理学结果显示:阿维菌素高、低剂量组大鼠肝组织个别汇管区均见少量单个核细胞浸润,并且在其周围发现少许轻微萎缩的肝细胞,其他脏器未见异常。 结论 阿维菌素可降低大鼠体重,对大鼠肝脏造成损伤,且氧化性损伤是阿维菌素毒作用机制之一。     

Evaluation of the toxic potentials of cypermethrin pesticide on some reproductive and fertility parameters in the male rats

Adult male Sprague-Dawley rats were exposed to tap water containing 0, 8,571, 17,143, or 34,286 ppm cypermethrin for 12 weeks. Based on water consumption per animal per day the rats received 13.15, 18.93, and 39.66 mg cypermethrin, respectively. Fertility was significantly reduced in male rats ingesting cypermethrin at a concentration of 13.15 and 18.93 mg in that the number of females impregnated by them was significantly reduced. The number of implantation sites was significantly reduced in females mated with males that had ingested cypermethrin at a concentration of 39.66 mg. A significant reduction in the number of viable fetuses was observed in females impregnated by the exposed males at all three doses of cypermethrin. The body weight gain was significantly lower in the treated males. Ingestion of cypermethrin at a concentration of 18.93 or 39.66 mg per day resulted in a significant increase in the weights of testes and seminal vesicles. Preputial gland weights were increased at all three concentrations of cypermethrin. Epididymal and testicular sperm counts as well as daily sperm production were significantly decreased in exposed males. The serum levels of testosterone, follicle-stimulating hormone and luteinizing hormone were significantly reduced in males exposed to 39.66 mg per day. Ingestion of cypermethrin at 18.93 and 39.66 mg/animal/day also resulted in a significant decrease in the perimeter and number of cell layers of the seminiferous tubules. The testes of treated animals were infiltrated with congested blood vessels with marked hemorrhage and a significant accumulation of connective tissue surrounding the seminiferous tubules, which contained a large number of immature spermatids. These results clearly demonstrate the adverse effects of cypermethrin pesticide on fertility and reproduction in male rats. Received: 1 January 2001/Accepted: 28 May 2001     

Effects of subchronic exposure of laboratory mice to benzylbutyl phthalate (BBP) on the quantity and quality of male germ cells

The aim of the study was to investigate the effect of 8-weeks exposure of male mice to benzyl butyl phthalate (BBP) on the sperm count and quality of gametes. Pzh:Sfis male mice exposed per os to 450 mg/kg bw (1/16 LD50) and to 1800 mg/kg bw (1/4 LD50) of BBP in olive oil were used in the study. Control mice were treated with olive oil only. Groups of animals were killed 4 and 8 weeks after the start of exposure and 4 weeks after he end of exposure. Sperm count, motility, morphology and DNA damage in gametes were estimated in the study. Sperm counts were diminished 4 and 8 weeks after the start of exposure to BBP. In the same time decrease in sperm motility and dose-dependent increase in the frequency of abnormal sperm heads and slight increase in DNA damage were noted. 4 weeks after the end of exposure, slight decrease in sperm counts in the group of 1/4 LD50 was observed, only. Correlation between sperm count and testes and epididymes weight were noted. Themost sensitive to BBP exposure occurred spermatozoa and spermatids.     

Seasonal patterns of LH, testosterone and semen quality in the Northern pintail duck (Anas acuta)

This study characterized seasonal changes in circulating LH and testosterone and in semen production and quality in the Northern pintail duck. Plasma LH and testosterone were measured in blood samples collected weekly throughout the year from eight males exposed to natural fluctuations in day length and temperature. Semen quality was evaluated weekly in these same males from April-June, the months when spermatozoa were produced. Semen quality (based on sperm concentration and normal morphology) peaked 0-2 weeks after sperm production onset and decreased sharply before sperm production cessation in late June. Nadir LH concentrations were measured in July and August with peak LH observed in May and November. There were clear seasonal patterns in circulating testosterone with July-September values being less (P<0.05) than October-December which, in turn, were less (P<0.05) than January-March. Maximal circulating testosterone (P<0.05) occurred during April-June, coincident with semen production. Weekly circulating LH during the breeding season was directly related to testosterone concentrations (P<0.01), but was not correlated to any specific semen or sperm trait (P>0.05). Testosterone concentrations throughout the breeding season were correlated (P<0.05) to total numbers of spermatozoa produced (volume x cell concentration) and percent normal sperm morphology. In summary, the Northern pintail experiences seasonal hormone fluctuations, with maximum circulating testosterone coinciding with peak ejaculate quality reflected by the production of high numbers of morphologically normal spermatozoa.     

饮用水中2,6-二氯-1,4-苯醌的体内急性毒性和遗传毒性研究

目的研究饮用水中2,6-二氯-1,4-苯醌(2,6-DCBQ)对小鼠的急性毒性和遗传毒性作用。方法选择健康6~8周龄SPF级昆明小鼠进行试验。将50只小鼠随机分为5组,分别为阴性对照(玉米油)组和215、464、1 000、2 150 mg/kg 2,6-DCBQ染毒组,每组10只,雌雄各半。采用一次性经口灌胃方式进行染毒,染毒容量为20 ml/kg。染毒后观察14 d,记录动物死亡数,计算其半数致死剂量(median lethal dose,LD50)。将50只小鼠随机分为5组,分别为溶剂对照(玉米油)组和62.5、125和250 mg/kg 2,6-DCBQ染毒组及阳性对照组(40 mg/kg环磷酰胺),每组10只,雌雄各半。采用灌胃方式进行染毒,染毒容量为20 ml/kg,两次灌胃间隔24 h;第二次灌胃后6 h,进行骨髓细胞微核试验。将50只雄性小鼠随机分为5组,分别为溶剂对照(玉米油)组和62.5、125和250 mg/kg 2,6-DCBQ染毒组及阳性对照组(40 mg/kg环磷酰胺),每组10只。采用经口灌胃方式进行染毒,染毒容量为20 ml/kg,连续灌胃5 d。染毒后第35天,进行精子畸形试验。结果 2,6-DCBQ对雄性、雌性小鼠经口急性毒性的LD50分别为501 mg/kg(95%CI:344~730 mg/kg)和584 mg/kg(95%CI:430~794mg/kg)。不同剂量2,6-DCBQ染毒组小鼠的骨髓细胞微核率及精子畸形率与溶剂对照组比较,差异均无统计学意义(P0.05)。各组PCE/NCE值均在正常范围内。结论 2,6-DCBQ对小鼠经口急性毒性属于低毒级,且未发现其具有遗传毒性。     

Age–related rump fat,fat percent,body fat mass,leptin, androgens and semen parameters of Arab stallions

ObjectiveTo study the effect of age and body fat on leptin levels and semen parameters of Arab horse.MethodsFifteen fertile Arab stallions of different ages belonging to Police Academy were divided into three equal groups according to their age. Old horses are those of >18 yeas (18–27), Mid-age horses ≥13 to 18 years (13–18), Young horses are those of <12 years (7–11). Semen was evaluated three times for each stallion. Blood and seminal plasma were assayed for measuring leptin, testosterone and estradiol. Subcutaneous rump fat thickness was measured using ultrasound for estimating body fat percent and fat mass percent.ResultsAll body fat parameters were significantly high in Young stallions and decreased with increasing age. As age increased, testosterone levels increases but leptin levels decreased. Age was inversely correlated with fat %, fat mass and leptin. All fat parameters had direct correlation with leptin in semen and serum but an inverse one with serum testosterone. Serum leptin directly correlated with sperm cell concentration in Mid-age stallions and inversely correlated with percent of live sperm in Old stallions. Semen leptin correlated directly with both percent of live sperm and percent of abnormal sperm in Old stallions.ConclusionThis study proved that aging in stallions is related to a drop in fertility, a decrease in body fat and in turn leptin. Arab stallions of age 7 to 18 years could be used in the breeding efficiently.     

Assessment of antifertility activities of abamectin pesticide in male rats

The effects of abamectin pesticide on fertility of adult male Sprague-Dawley rats were investigated. Adult male rats were exposed to tap water containing 0, 571, 857, or 1714 ppm abamectin for 6 weeks. Based on fluid consumption, animals received 0, 1.19, 1.87, and 2.13 mg/animal/day abamectin, respectively. Fertility was significantly reduced in male rats ingesting abamectin at all three doses in that the number of females impregnated by them was significantly reduced. The number of viable fetuses was significantly reduced in females mated with males that ingested abamectin at 1.87 or 2.13 mg/animal/day. Significant increases in the total number of resorptions and the number of females with resorptions were observed in females mated with the exposed males at all three concentrations. The body weight gain and water consumption were significantly lower in males that ingested 2.13 mg/animal/day abamectin. Likewise, ingestion of abamectin at all three concentrations caused a significant increase in the weight of testes. Epididymal and testicular sperm counts and daily sperm production were significantly decreased in exposed males. The serum level of testosterone was significantly reduced, whereas the serum level of follicle-stimulating hormone was significantly increased in males that ingested abamectin at a concentration of 2.13 mg/animal/day. Histological evaluation of the testes revealed several abnormalities including infiltration with congested blood vessels with marked hemorrhage and a significant accumulation of connective tissue surrounding the seminiferous tubules. These results strongly suggest the adverse effects of abamectin pesticide on male rat fertility.     

Effect of oral tamoxifen on semen characteristics and serum hormone profile in male bonnet monkeys

The effects of oral tamoxifen were studied at a dose of 0.4 mg/kg per day, on the serum hormones and semen parameters in adult male bonnet monkeys, for a period of 90 days. Honey was used as vehicle. Monkeys were treated with honey for 30 days, followed by tamoxifen from Day 30-120 (90 days). Thereafter the treatment was withdrawn until Day 150 of schedule. Blood samples were drawn at 12 and 24 clock hours at monthly intervals for the analysis of luteinizing hormone, follicle-stimulating hormone and testosterone. Semen samples were also collected for analysis once a month, from Day 0-150 of exposure. Tamoxifen treatment produced a transient but significant increase in circulating gonadotropins, at Day 90 of treatment schedule, corresponding to 60 days of treatment. Whilst serum testosterone levels were normal throughout treatment period, an increase was observed after 30 days of drug withdrawal. No effect of oral tamoxifen was evident on semen parameters, viz., volume, counts, morphology and motility. However, throughout the exposure period to honey, a significant increase was observed in sperm counts without any effect on testosterone levels. The present study suggests that oral tamoxifen has a transient antiestrogenic effect on the serum hormones and no effect on semen parameters of adult nonhuman primate males. It is concluded that bioefficacy of oral tamoxifen may have been reduced due to hepatic metabolism.     

Testicular toxicity evaluation of two antimony compounds, antimony trioxide and antimony potassium tartrate, in rats and mice

Objectives Testicular toxicities of antimony compounds were evaluated in rats and mice. The slightly water-soluble antimony compound antimony trioxide (ATO) and the highly water-soluble antimony compound antimony potassium tartrate (APT) were examined. Methods Daily doses of the compounds were 27.4, 12.0 and 1,200 mg/kg body weight in the APT group, low-ATO group and high-ATO group, respectively. The corresponding daily doses of antimony were 10, 10 and 1,000 mg/kg body weight, in the APT group, low-ATO group and high-ATO group, respectively. Both compounds were administered by gavage: rats, 3 days per week for 4 weeks; mice, 5 days per week for 4 weeks. Results Neither compound reduced the weights of reproductive organs or accessory sex organs nor affected sperm parameters. Few marked histopathologic changes were found in the testes of the treated animals. Even at 1,200 mg/kg body weight, which is greater than the LD₅₀ of APT, ATO produced no effects. Conclusions In this study, it was found that ATO and APT are not toxic to testes in rodents.     

Trials for development of once-a-month injectable, hormonal male contraceptive using dienogest plus testosterone undecanoate: dose standardization, efficacy and reversibility studies in rats

Background

The study was conducted to test the potential of using dienogest (DNG) plus testosterone undecanoate (TU) in rats for development of a once-a-month injectable male hormonal contraceptive.

Study Design

Dose selection studies were initiated with administration of DNG in three different doses of 20, 30 and 40 mg/kg body weight (bw) per week plus TU 25 mg/kg bw once in every 6 weeks. Status of spermatogenesis and sperm count in epididymis was evaluated. The frequency of DNG intervention was later extended to every 2- and 4-week intervals. Mating studies, toxicity and reversibility of spermatogenesis following stoppage of treatment were carried out with DNG 40 mg/kg bw at 4-week intervals.

Results

Complete arrest of spermatogenesis was observed after 60 days of treatment at all doses of DNG (20, 30 and 40 mg/kg bw per week)+TU. However, weights of testis and accessory sex organs (epididymis, prostate and seminal vesicle) declined significantly 60 days post treatment compared to vehicle-treated controls. Epididymis in the treated animals was completely devoid of sperm. When the frequency of DNG injection (20 mg/kg bw) was extended to once every 15 days, a few immotile and decapitated sperm were observed in the epididymis. With TU treatment unchanged, animals receiving DNG (40 mg/kg bw) once either every 2- or 4-week intervals demonstrated good and uniform arrest of spermatogenesis. DNG 40 mg/kg per 4 weeks+TU also demonstrated a significant rise in germ cell apoptosis in the seminiferous epithelium. There was no significant increase in the serum high-density lipoprotein and low-density lipoprotein levels at the end of 120 days of treatment. Following withdrawal of treatment after 60 or 120 days, qualitative restoration of spermatogenesis was rapid in the former compared to the latter.

Conclusion

Dienogest plus TU has the potential for development as a monthly injectable showing reversible hormonal male contraception with good efficacy.     

Anti-apoptotic effects of curcumin on cadmium-induced apoptosis in rat testes

Cadmium (Cd) is one of the environmental pollutants affecting various tissues and organs including testis. The aim of this study was to investigate the anti-apoptotic effects of curcumin (Cur) on Cd-induced apoptosis in rat testes. The rats were randomly allotted into one of three experimental groups: control, Cd treated and Cd treated with Cur; each group contained 10 animals. The control group received 2 ml/day of dimethyl sulfoxide (DMSO). To induce toxicity, Cd (1 mg/kg body weight) was dissolved in normal saline and subcutaneously injected into rats for 4 weeks. The rats in Cur-treated group was given a daily dose of 100 mg/kg of Cur for 4 weeks. To date, no examinations of the anti-apoptotic properties of Cur on Cd-induced apoptosis in rat testes have been reported. The mean seminiferous tubule diameter, mean testicular biopsy score values and serum testosterone levels were significantly decreased in Cd-treated groups were compared to the control group. Furthermore, the Cur-treated animals showed an improved histological appearance and serum testosterone levels in Cd-treated group. Our data indicate a significant reduction in the activity of in situ identification of apoptosis using terminal dUTP nick end-labeling in testis tissues of the Cd-treated group with Cur therapy. The present study showed that Cur treatment protected testes against toxic effects of Cd. We believe that further preclinical research into the utility of Cur may indicate its usefulness as a potential treatment on the spermatogenesis after testicular injury caused by Cd-treated rats.     

农达对小鼠生精作用的影响

目的探讨农达(roundup,活性成分为草甘膦)对小鼠生精作用的影响。方法将24只成年SPF级雄性Balb/c小鼠随机分为阴性对照(蒸馏水)组和20、200、2 000 mg/kg农达染毒组,每组6只。采用经口灌胃方式进行染毒,染毒容量为20 ml/kg,每天1次,连续染毒30 d。测定小鼠精子数量、精子活动率和血清中睾酮(T)浓度及睾丸生精细胞的凋亡情况。结果与阴性对照组相比,200、2 000 mg/kg农达染毒组小鼠精子数量减少、精子活动度降低;各剂量农达染毒组小鼠血清睾酮浓度均降低,而睾丸生精细胞的凋亡率均升高,差异均有统计学意义(P0.05)。结论在本实验染毒时间和剂量范围内,农达对雄性Balb/c小鼠的生精功能有一定的毒性作用。     

Testicular toxicity of chlorpyrifos (an organophosphate pesticide) in albino rat

Organophosphates are among the most widely used synthetic insect pesticides. The widespread use of organophosphates has stimulated research into the possible existence of effects related with their reproductive toxic activity. Present study was therefore, undertaken to assess the effects of chlorpyrifos on testes, the main organ of male reproduction. Chlorpyrifos at the dose levels of 7.5, 12.5 and 17.5 mg/kg b. wt./day was administered orally to male rats of Wistar strain for 30 days to evaluate the toxic alterations in testicular histology, biochemistry, sperm dynamics and testosterone levels. The body weight of animals did not show any significant change, however, a significant reduction was observed in testes. Chlorpyrifos also brought about marked reduction in epididymal and testicular sperm counts in exposed males and a decrease in serum testosterone concentration. Histopathological examination of testes showed mild to severe degenerative changes in seminiferous tubules at various dose levels. Fertility test showed 85% negative results. A significant reduction in the sialic acid content of testes and testicular glycogen was noticed, whereas the protein and cholesterol content was raised at significant levels. All these toxic effects are moderate at low doses and become severe at higher dose levels. From the results of the present study it is concluded that chlorpyrifos induces severe testicular damage and results in reduction in sperm count and thus affect fertility. Small changes in sperm counts are known to have adverse affects on human fertility. Therefore, application of such insecticide should be limited to a designed programme.