Effects of ethanol ingestion on epididymal glycosidases and fertility in the rat

Epididymal glycosidases play a role in sperm maturation by modifying sperm surface glycoproteins. To study the effects of ethanol on epididymal sperm maturation, ethanol (3 g/kg body weight as 25%, v/v) was administered to a group of rats by gastric-intubation twice daily for 30 days. In another group, rats were also treated with alcohol for 30 days but were then withdrawn from treatment for 30 days to assess the reversibility of ethanol-induced effects. Ethanol-induced changes in epididymal tissue and sperm glycosidases, cauda epididymal sperm motility and the fertility of rats were assessed. Ethanol treatment caused a marked decrease in the specific activities of glycosidases in both tissues and spermatozoa from epididymal segments. Cauda epididymal sperm motility and the fertility of ethanol-treated rats were significantly impaired compared to control rats fed an isocaloric diet. These changes are likely to be the consequence of direct and indirect effects of ethanol mediated through subnormal testosterone and dihydrotestosterone. Most of these changes were found to be reversible. The present study suggests that impaired activity of sperm glycosidases may be one of the factors responsible for defective sperm motility and fertilizing potential in ethanol-treated rats.     

Addition of specific metabolites to bovine epididymal cell culture medium enhances survival and motility of cryopreserved sperm

We have developed a cell culture system of bovine epididymal epithelium in which cryopreserved bovine sperm motility was efficiently maintained for many hours. The culture conditions to maintain viable epididymal cells are quite different from conditions normally used to incubate sperm cells. Thus, we have modified a previously described principal cell medium (PCM; Moore et al, 1992) using HEPES as a buffer and supplemented media with myo-inositol, pyruvate, lactate, glycerol, and carnitine to mimic epididymal intraluminal conditions. In the first experiments the effects of PCM and our epididymal cell medium (ECM) on sperm motility were compared in the absence of cells and evaluated by microscopic analysis under a phase contrast microscope or using the Hamilton Thorn Image Analyzer System. Our results showed that motility of cauda epididymal sperm was significantly higher in ECM than in PCM during a 48-hour incubation period when both media were supplemented with 10% fetal bovine serum (FBS). We then replaced FBS with bovine serum albumin (BSA) or no proteins at all to verify if ECM was able to enhance sperm survival. To test this aspect we used frozen-thawed sperm, which survived up to 48 hours when sperm cells were coincubated with epididymal cell monolayers. Hence, PCM, ECM, and different media containing each metabolite of ECM were supplemented with 0.5% BSA to assess motility of thawed sperm after an incubation period of 6 hours. A positive effect on sperm motility was observed in all fresh and unconditioned media containing 1 mM pyruvate. Motion parameters were more efficiently maintained in all conditioned media than in unconditioned media. Our results showed, however, that pyruvate was almost completely oxidized or consumed by epididymal cells during preincubation of culture media. We conclude that motility of frozen-thawed bovine spermatozoa can be improved using a culture medium or a medium conditioned by epididymal cell cultures without carnitine but containing mainly pyruvate, inositol, glycerol, and lactate.     

Seminal carnitine, epididymal function and spermatozoal motility

The carnitine content of semen from azoospermic subjects and subjects with either impaired motility or forward progression is reported. Within the azoospermic group, the values were not significantly different between those with testicular failure or obstruction. The patients with impaired motility (less than 40%) or impaired forward progression (less than 3) had a lower mean seminal carnitine content than those with good motility and forward progression (P less than 0.05). Seminal carnitine concentration was not an index of epididymal patency and could not be regarded as useful for locating the level of obstruction in the epididymis. Since carnitine plays an important role in the maturation process when sperm acquire motility, it would seem that seminal carnitine might be an indicator of epididymal dysfunction.     

Effects of altered epididymal sperm transit time on sperm quality

The epididymal sperm transit time seems to have an important role in the process of sperm maturation, and it seems that alterations to the transit can harm the process. The aim of the present work was to evaluate the influence of altered sperm transit time through the epididymis on sperm parameters and fertility of rats, as well as the role of testosterone in the alterations. Sprague–Dawley adult male rats were randomly assigned to four different groups and were treated for 12 days: (i) 10 μg/rat/day DES, to accelerate the transit; (ii) 6.25 mg/kg/day guanethidine sulphate, to delay the transit; (iii) same treatment as group 1, plus androgen supplementation; (iv) control animals received the vehicles. Guanethidine treatment delayed the sperm transit time through the epididymal cauda, provoking increased sperm reserves in this region. Animals exposed to DES showed an acceleration of sperm transit time in the epididymis, and consequently decreased sperm density in both epididymal regions, the caput-corpus and cauda, and diminished sperm motility. In both cases sperm production was not altered. Testosterone supplementation was able to restore the transit time to values close to normality, as they were higher than in the control rats. The same occurred in relation to sperm motility. Rats exposed to DES presented lower fertility after in utero artificial insemination using sperm collected from the proximal cauda epididymis. Therefore, it was concluded that the acceleration of rat sperm transit time appeared to harm normal sperm maturation, thus decreasing sperm quality and fertility capacity, in an androgen-dependent way.     

Effects of smoking on testicular function and fertilizing potential in rats

We evaluated the effects of smoking on testicular function and fertilizing potential in rats. Twenty rats (group A) were exposed to the smoke of 20 cigarettes for 1 h per day. Ten rats (group B) were exposed to the smoke of 40 incense sticks for 1 h per day, and an additional 10 rats served as a control group (group C). After 10 weeks of daily exposure, serum levels of nicotine and cotinine were assessed, and a mating test was conducted. Five days later, serum concentrations of testosterone before and after human chorionic gonadotropin (hCG) stimulation, gonadotropins, and epididymal sperm content and motility were evaluated. In addition, in vitro fertilization was carried out. Nicotine and cotinine were detected in group A, but not in groups B and C. Basal serum testosterone and gonadotropin concentrations did not differ significantly among the three groups, but the testosterone response to hCG stimulation was significantly lower in group A than in groups B and C. Group A showed significant reductions in epididymal sperm content and motility, and in fertility in vivo and in vitro. These findings suggest that smoking leads to a secretory dysfunction of the Leydig cells, and also a deficiency in sperm maturation and spermatogenesis. In addition, smoking has a detrimental effect on sperm fertilizing potentials in vivo and in vitro. Received: 18 December / Accepted: 27 May 1997     

Toxicity of ornidazole and its analogues to rat spermatozoa as reflected in motility parameters

Ornidazole, a 5-nitro-imidazole derivative, has contraceptive properties in rats. As some ornidazole passes through the body unmetabolized after administration, the aim of this study was to investigate if ornidazole itself has a direct effect on sperm motility and whether these effects are limited or potentiated by the epididymal epithelium or structural changes to the molecule. Cauda epididymal spermatozoa or cauda epididymal tubules were incubated with ornidazole or ornidazole analogues, and motility parameters were subsequently measured by means of a computer-assisted sperm analysis (CASA) system. Incubation of spermatozoa in 2.5 mmol/L ornidazole for 4 h reduced their motility significantly, whereas incubation of epididymal tubules for 8 h in 10 mmol/L ornidazole was required to alter the velocity parameters of the enclosed spermatozoa upon release, suggesting that extratubular non-metabolized ornidazole can participate in inhibiting the motility in vivo. The in vitro toxicity of ornidazole derivatives depends on the halogen present and on the position of the nitro-group. The putatively inactive (R)- and the active (S)-ornidazole exhibited equivalent depression of sperm motility by direct incubation. This observation, and the differences between the in vitro and the in vivo efficacies of various ornidazole analogues, indicates distinct mechanisms of motility inhibition in the two experimental systems.     

Cryoprotective effect of l‐carnitine on motility,vitality and DNA oxidation of human spermatozoa

Successful cryopreservation for human spermatozoa markedly influences the reproductive outcomes of assisted reproductive technologies. But in spite of its usefulness, cryopreservation significantly decreases sperm quality. l ‐carnitine has been found to improve the quality of spermatozoa in selected cases with male infertility. Here, we examined the efficacy of l ‐carnitine in improving sperm motility and vitality and reducing sperm DNA oxidation during cryopreservation. Semen samples from infertile patients (n = 22) were collected and analysed. Cryopreservation medium supplemented with l ‐carnitine was mixed with the semen at a ratio of 1 : 1 (v/v). The final l ‐carnitine concentration in each cryovial was 0.5 mg ml^?1 per 5 × 10⁶ cell ml^?1. Controls were cryopreserved without addition of l ‐carnitine. After 24 h of cryopreservation, thawed sperm samples were analysed for motility, vitality and DNA oxidation. Sperm vitality was assessed by the eosin–nigrosin test, while sperm DNA oxidation was measured by flow cytometry. Addition of l ‐carnitine significantly improved sperm motility and vitality (P < 0.05) compared with the control. The flow cytometry experiment showed no statistical difference (P > 0.05) in the levels of DNA oxidation between samples and controls. In conclusion, l ‐carnitine improves human sperm motility and vitality, but has no effect on sperm DNA oxidation after cryopreservation.     

Antispermatogenic activity of Morinda lucida extract in male rats

Aim： To investigate the effect of Morinda lucida Benth （Rubiaceae） on the reproductive activity of male albino rats. Methods： Two groups of rats were treated with 400 mg/（kg.d） of Morinda lucida leaf extract for 4 and 13 weeks, respectively. The control rats received the vehicle. All the treated rats had corresponding recovery groups. At the end of each experimental period, animals were killed and organ weights, sperm characteristics, serum testosterone levels, histology of the testes and fertility were assessed. Results： Morinda lucida leaf extract did not cause any changes in body and somatic organ weights, but significantly increased the testis weight （P 〈 0.05）. The sperm motility and viability, and the epididymal sperm counts of rats treated for 13 weeks were significantly reduced （P 〈 0.05）. Sperm morphological abnormalities and serum testosterone levels were significantly increased （P 〈 0.05）. There were various degrees of damage to the seminiferous tubules. The extract reduced the fertility of the treated rats by reducing the litter size. Reversal of these changes, however, occurred after a period of time. Conclusion： The extract of Morinda lucida has reversible antispermatogenic properties.     

大鼠附睾精子运动调节的有关因子研究

精子在附睾成熟中其运动能力的获得和发展过程十分复杂，受众多因素的影响和调节，包括附睾内精子本身因素、附睾内环境及一些附睾内调节因子对精子的作用。我们用附睾微穿刺等技术获得附睾液，并分别应用生物化学、生物发光等方法分段研究了大鼠附睾精子成熟过程中精子ＡＴＰ、钙调蛋白和附睾液肉毒碱含量及其活性变化规律。结果发现大鼠附睾液内肉毒碱含量随附睾头、体、尾移行而逐渐增加，均值（－χ±Ｓ－χ）分别为４８．７±３．６４．２±３．６、９０．２±５．３ｍｍｏｌ／Ｌ；附睾精子ＡＴＰ含量（×１０－１０ｍｏｌ／ｌ０６精子）也呈此种变化，分别为１．５±０．２、２．８±０．４、４．６±２．５；附睾精子钙调蛋白活性（×ｌ０－４ｎｍｏｌ／ｌ０８精子）分别为２．６±０．７、３３±０．７、１．４±０．２，其中以体部精子最高，尾部精子最低。并针对该结果及这些调节因子对精子附睾成熟中运动能力的调节作用及其机理作了一些探讨。     

Effects of date seed oil on testicular antioxidant enzymes and epididymal sperm characteristics in male mice

The aim of this study was to evaluate the effect of date seed oil (DSO) on epididymal sperm characteristics and testicular antioxidant enzymes in male mice. DSO was diluted into isotonic saline solution (0.9%) and different doses (5, 10, 15 and 20%) were prepared. Fifty male mice were divided into five groups; in four groups DSO was given by intraperitoneal injection of oil solution for 28 days. The control group was injected by isotonic saline solution without DSO. Body and reproductive organ weights, sperm characteristics (count, motility, viability and morphology) were assessed. In addition, levels of malondialdehyde (MDA), activities of superoxide dismutase (SOD) and catalase (CAT) were investigated in testes. A significant increase in sperm count, motility and viability of all treated animal groups was observed when compared with the control group ( P  < 0.05). Unlike, the percentage of abnormal sperm was significantly lower in all treated groups than in the control group ( P  < 0.05). A significant decrease in MDA levels and marked increase in SOD and CAT activities in mice treated with high doses of DSO (15 and 20%) were also noted. We suggest that DSO can improve the epididymal sperm quality and could ameliorate the testicular strategy defences.     

Effect of alpha-chlorohydrin on epididymal sperm and epididymal plasma in swine.

Investigation of the contraceptive mechanism of alpha-chlorohydrin was done by analyses of epididymal plasma and certain epididymal sperm characteristics after oral administration of 0, 5, 10 or 30 mg/kg, day of the drug to boars for 15 days. Water resorption in caput epididymidis was slightly decreased in all treatment groups. Sodium, potassium, chloride, glycerylphosphorylcholine levels, and seminal antigens in epididymal plasma were not altered significantly by 10 or 30 mg/kg of the drug. The boars on 5 mg/kg exhibited significantly elevated sodium, potassium, or chloride values in various segments. Motility was significantly lower on corpus and proximal cauda epididymal spermatozoa from alpha-chlorohydrin treated boars. Only boars receiving 30 mg/kg exhibited impaired sperm motility in the distal cauda. The movement of the cytoplasmic droplets to the distal position was retarded in boars on the two highest dose levels. The results suggest that the contraceptive effects of alpha-chlorohydrin in the boar is probably not mediated via an impaired epididymal function.     

The effect of ketoconazole on endocrine and reproductive parameters in male mice and rats.

Ketoconazole has been shown to reduce steroidogenesis by inhibiting the cytochrome P-450 enzymes in these pathways. This finding, along with the observation that the compound reduces sperm motility, led us to study the effectiveness of ketoconazole as a male contraceptive agent administered in acute and chronic studies of both rats and mice. Four hours after a single administration, male rats showed significant reductions in both serum testosterone and corticosterone levels that completely recovered (testosterone) or nearly recovered (corticosterone) 24 hours after administration. Chronic administration of ketoconazole to male rats and mice resulted in steroid levels comparable with those of control animals. Epididymal sperm motility was only slightly reduced in male mice 4 hours after administration of the drug. No effect on sperm motility was noted after chronic administration in either species studied. In vitro exposure of epididymal sperm to ketoconazole resulted in a significant reduction of sperm motility. Breeding trials after ketoconazole administration resulted in normal fertility and fecundity even at the highest dosage studied. The lack of correlation between steroid levels and sperm immobilization, along with rapid in vivo and in vitro effects on sperm motility, suggests that the reduction in sperm motility is not related to a decrease in steroid levels. From these data, the authors conclude that ketoconazole is probably not a viable approach to the development of a male contraceptive.     

Effects of Chronic Renal Failure on Hypothalamo-Pituitary-Testicular Axis Function and Fertility in Rats

Background: We evaluated the effects of chronic renal failure on hypothalamo-pituitary-testicular axis function in male Wistar rats.
Methods: Chronic renal failure was induced by five-sixths nephrectomy in male rats. Seven to 10 weeks after the surgery, serum urea and creatinine concentrations and hematocrits were evaluated, and human chorionic gonadotropin (hCG) and gonadotropin-releasing hormone (GnRH) tests, and prolactin stimulating antl suppression tests were performed. In addition, androgen-binding protein, epididymal sperm content, motility, ancl fertile potential were assessed.
Results: Basal serum testosterone concentrations and the response of testosterone to hCG were significantly lower in rats with chronic renal failure than in controls. Basal serum gonadotropin levels were elevated in rats with chronic renal failure, but the gonadotropin response to GnRH did not differ from that in controls. Serum protactin IeveIs responded appropriately to stimuIation and suppression tests. Androgen-binding protein levels, epididymal sperm content, motility, and fertile potential were significantly lower in uremic rats.
Conclusions: Chronic rend failure in rats interferes with endocrinologic mechanisms and testicular functions. Thus, uremic rats have a low fertile potential.     

Lack of correlation between fertility and sperm numbers in male rats treated with histrelin, a potent LHRH agonist

Adult male rats were treated daily for up to 8 weeks with histrelin, [(ImBzl)-D-His6, Pro9-NEt]LHRH, to study the antifertility effects of this LHRH agonist. Although serum testosterone concentrations and testicular sperm numbers were significantly decreased by weeks 2 and 4 respectively, a reduction in fertility, as judged by the mean number of fetuses per mated female, was not observed until the sixth week of treatment. Furthermore, the number of spermatozoa in the cauda epididymidis of treated rats did not decrease below initial control levels at any time during the study and full fertility returned within 4 weeks after histrelin treatment was stopped. Thus, the lack of correlation between fertility and testicular and epididymal sperm numbers suggests that the antifertility effects of LHRH agonists are not due solely to reduced sperm numbers, but also result from androgen deficiency.     

Sexual behaviour, sperm quantity and quality after short-term streptozotocin-induced hyperglycaemia in rats

Studies of diabetes mellitus in the streptozotocin rat model suggest that sexual dysfunctions may result from diabetes-induced alterations of the neuroendocrine-reproductive tract axis. Our investigation was performed to better define the effects of short-term hyperglycaemia on rat epididymal sperm quantity, quality and transit time, using both natural mating and artificial in utero insemination protocols. Male rats were made diabetic with streptozotocin (sc, 40 mg/kg), whereas controls received vehicle. Sexual behaviour was tested after 15 days and sperm fertilizing ability was checked 22 days after the injection through natural mating and artificial in utero insemination. Other parameters such as daily sperm production, testosterone levels, as well as sperm morphology and motility were also investigated. Fifty per cent of the diabetic animals showed no copulatory behaviour during tests and the number of animals reaching ejaculation was smaller in the diabetic group when compared with the control group (33% vs. 83%). Diabetes resulted in decreased body and reproductive organ weights, as well as diminished sperm counts in the testis and epididymis, that were associated with diminution of plasmatic testosterone levels. After natural mating, there was a decrease in the fertility in the diabetic adult male rats (25.5%) compared with control animals (81.5%). However, distal cauda epididymal sperm from diabetic rats displayed normal fertilization ability (91.5%) using in utero insemination. There were no effects of hyperglycaemia on sperm transit time in the epididymis and on spermatogenesis. Our results indicate that diabetes mellitus produces reproductive dysfunction, but does not compromise sperm fertilizing ability in the cauda epididymis in this experimental model.     

Antioxidant effect of manganese on the testis structure and sperm parameters of formalin‐treated mice

Manganese inhibits oxidative stress damage. The aim of this study was to investigate the protective role of manganese on testis structure and sperm parameters in adult mice exposed to formaldehyde (FA). Twenty adult male NMRI mice were selected and randomly divided into four groups: (i) control; (ii) sham; (iii) ‘FA’‐exposed group; and (iv) ‘FA and manganese chloride’‐exposed group. The FA‐exposed groups received 10 mg kg^?1 FA daily for 14 days, and manganese chloride was just injected intraperitoneally 5 mg kg^?1 on 2nd weeks. Mice were sacrificed, and spermatozoa were collected from the cauda of the right epididymis and analysed for count, motility, morphology and viability. The other testicular tissues were weighed and prepared for histological examination upon removal. Seminiferous tubules, lumen diameters and epithelium thickness were also measured. The findings revealed that FA significantly reduced the testicular weight, sperm count, motility, viability and normal morphology compared with control group (P ≤ 0.05). In addition, seminiferous tubules atrophied and seminiferous epithelial cells disintegrated in the FA group in comparison with the control group (P ≤ 0.05). However, manganese improved the testicular structure and sperm parameters in FA‐treated mice testes (P ≤ 0.05). According to the results, manganese may improve and protect mice epididymal sperm parameters and testis structure treated with FA respectively.     

Combined effects of chronic hyperglycaemia and oral aluminium intoxication on testicular tissue and some male reproductive parameters in Wistar rats

Exposure to either environmental toxicants or chronic hyperglycaemia could impair male reproductive function. However, the extent to which exposure to such toxicants, in the presence of pre‐existing metabolic dysfunction, could affect male reproduction is unclear. Streptozotocin‐induced diabetic Wistar rats (12 weeks old) were exposed to oral aluminium chloride at 250 ppm for 30 days; followed by evaluation of caudal epididymal sperm count and motility, assay for serum follicle stimulating hormone (FSH), testosterone (T) and oestradiol; and assessment of testicular histology. Moreover, blood glucose was evaluated by the glucose oxidase method. In rats treated with streptozotocin (STZ) or aluminium (Al) alone, erosion of testicular parenchyma and stroma was observed. This effect was most severe in diabetic rats simultaneously exposed to Al; coupled with reduced caudal epididymal sperm count that was least in this (STZ+Al) group (18.75 × 10⁶ ml^?1) compared with controls (61.25 × 10⁶ ml^?1; P < 0.05), STZ group or Al group. Moreover, these reproductive perturbations (in the STZ+Al group) were associated with reduced sperm motility and significantly reduced serum FSH (P < 0.05); but elevated serum T and oestradiol (P < 0.05), compared with control. These suggest that diabetes‐induced testicular lesion is exacerbated by simultaneous oral Al toxicity in Wistar rats.     

Temporary sterilization of the male by intravasal contraceptive device (IVCD): a preliminary communication

The described procedure aims at providing a subfertile sperm count by obstructing the lumen of the vas deferens by a wire made of nonreactive synthetic material which can be removed easily to restore fertility. This is a preliminary report of 2 cases. Thick nylon wire, the size of chromic catgut no 1, was used as the IVCD. With an eyeless needle the wire was inserted for about 3 cm into the lumen of the vas across a transverse vastotomy incision. Each end was brought out and knotted. Black silk thread was used as a marker for identification. The vasotomy and other structures were closed and an antibiotic given. In 1 patient, in whom 2 parallel wires were inserted, the sperm count was reduced from an average of 75 million per ml with 70% motility to 3 million per ml with 30% motility while the IVCD was in place for 20 weeks. After removal the sperm count rose in 6 weeks to an average of 60 million per ml with a motility of 70%. A second patient with similar preoperative sperm count continues with the IVCD in place with an average of 12.3 million sperm count per ml. It is considered that sperm counts resulting are below fertility level. Other synthetic materials are being studied. An IVCD with a needle on each end is now available to facilitate insertion.     

Motility Related to the Presence of Carnitine/Acetyl-Carnitine in Human Spermatozoa

Total carnitine, acetylcarnitine and carnitine acetyl transferase (E.C. 2.3.1.7) were measured in the plasma and spermatozoa fractions of 41 samples of human semen and the correlation with sperm motility and sperm density examined.
It was confirmed that the concentration of total carnitine as well as of acetylcarnitine was 2–25 times higher and the activity of carnitine acetyl transferase 20–15 fold higher in spermatozoa than in seminal plasma. Sperm motility correlated with the concentration of acetylcarnitine (r = 0.6, P < 0.01) and of total carnitine (r = 0.55, P < 0.01) but not with the concentration of free carnitine nor with the activity of carnitine acetyl transferase in the spermatozoa. No correlation was found between sperm motility and the concentrations of acetylcarnitine, free carnitine or total carnitine in the seminal plasma.
It is concluded that the amount of carnitine present in the spermatozoa probably provides a better index of epididymal function than the carnitine in the seminal plasma as the latter in influenced by af variable contribution from the other accessory sex organs.     

Effects of α-Interferon on Sperm Production, Concentration, and Motility in the Rat

Background :
We evaluated possible effects of α-interferon (α-IFN) on testicular spermatogenesis and epididymal sperm quality in the nude rat.
Methods :
Nude male rats were administered subcutaneous injections of human α-IFN daily for 3 months. The luminal content of the cauda epididymidis was collected by micropuncture. Daily sperm production was determined by Amann's method and sperm concentrations were determined by microassay. Progressive motility was judged by evaluating the linear distance traveled by the sperm in a diluent. Serum levels of testosterone, luteinizing hormone (LH), and follicle stimulating hormone (FSH) were also measured at the end of the experiment.
Results :
Daily sperm production and epididymal sperm concentrations were significantly increased after administration of α-IFN, while progressive motility of the spermatozoa was not altered. α-IFN significantly increased serum testosterone levels, while it decreased serum LH levels and left serum FSH levels unchanged.
Conclusion :
α-IFN may improve testicular spermatogenesis and increase the epididymal sperm concentration in the rat. These promising results with α-IFN may pave the way for a new approach to treating male infertility.