Epididymal Sperm Concentration Research Articles

Effects of piperine on testis of albino rats

Piperine was administered to mature male albino rats at doses of 5 and 10 mg/kg body weight, p.o., respectively, for 30 days. Only a 10 mg dose of piperine treatment caused a significant reduction in the weights of testis and accessory sex organs. Histological studies revealed that piperine at a 5 mg dose caused partial degeneration of germ cell types, whereas at a 10 mg dose, it caused severe damage to the seminiferous tubule, decrease in seminiferous tubular and Leydig cell nuclear diameter and desquamation of spermatocytes and spermatids. Correlated to the structural changes, a fall in caput and cauda epididymal sperm concentrations was also evident. A 10 mg dose of piperine also caused a marked increase in serum gonadotropins and a decrease in intratesticular testosterone concentration, despite normal serum testosterone titres.

Triptolide: a potential male contraceptive.

The antifertility effect of triptolide and other related compounds, isolated from Tripterygium wilfordii, has been demonstrated in male rats. The exact sites and mechanism of action of triptolide remain unknown. Our objectives were to determine whether triptolide at selected dose levels that induce infertility has any detrimental effects on the testes and to determine the sites and the possible mechanisms of its action. Groups of six adult male Sprague-Dawley rats were given oral administration of either vehicle (control group) or triptolide (50 or 100 microg/kg body weight) daily for 35 or 70 days. Body weight gain was normal in all treated groups. All six rats treated with a high dosage of triptolide were infertile during the second (63-70 days) mating trial. A lower dose (50 microg) of triptolide gave intermediate fertility values. Plasma levels of luteinizing hormone, follicle-stimulating hormone, testosterone, and intratesticular testosterone were not significantly different between control and triptolide-treated groups. Cauda epididymal sperm content was decreased by 68% and the motility, which averaged 58.2% in the control rat, was reduced to almost zero. No effects of triptolide were observed on testis and accessory organs weight, volumes of tubular lumen and the total Leydig cells, tubule diameter, and the number of Sertoli cells, spermatogonia, preleptotene (PL), and pachytene (P) spermatocytes. There were, however, modest but significant decreases in tubule volume and the number of round spermatids at stages VII-VIII. No changes in the germ cell apoptotic index measured at stages VII-VIII and XIV-I were noted between controls and rats rendered infertile with a high dose of triptolide. Thus, triptolide, at a dose level that induces complete infertility in the adult rats, has minimal adverse effects on the testes and acts primarily on the epididymal sperm making triptolide an attractive lead as a post-testicular male contraceptive.

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.

THE EFFECTS OF CHRONIC EXERCISE ON METABOLIC AND REPRODUCTIVE FUNCTIONS IN MALE RATS

Previous studies concerning the effects of swimming on various endocrine gland functions have been performed [4, 6]. Our study was thus designed to analyze the effects of chronic exercise (swimming) on the resting metabolic rates (RMR) of adult rats. Most of the protocols used a water temperature of 33 C. It is our contention that such a protocol is not exclusively an exercise stress, but also a hypothermic stress [10]. The protocol of our study was designed in a way that hypothermic stress was not part of the exercise stress. Male rats were swam in 36 C water for 3 hours a day, 5 days a week for 4 months. RMR of the animals were determined 24 h after the next to last swim session. Plasma hormone levels and epididymal sperm concentrations were determined in animals sacrificed 24 h after the last swim period. Exercising animals had a RMR 16% greater than that of control animals (p < 0.02), yet total and free thyroxine and total and free triiodothyronine were not significantly elevated. Neither plasma testosterone nor epididymal sperm counts were significantly reduced in the exercising animals. It appears that chronic exercise produces an elevation in RMR which is unrelated to thyroid gland activity and does not suppress the hypothalamic-pituitary-gonadal axis.

Epididymal sperm retrieval by epididymal micropuncture combined with intracytoplasmic sperm injection: difference between acquired and congenital irreparable obstructive azoospermia.

To evaluate the differences in fertilization and pregnancy rates following intracytoplasmic sperm injection (ICSI) of retrieved epididymal sperm between congenital (group 1) and acquired (group 2) unreconstructable obstructive azoospermic patients, we compared the outcome of the ICSI procedure between these two groups. Thirty-six patients with obstructive azoospermia received epididymal sperm retrieval by the micropuncture method for the ICSI procedure. Main parameters evaluated were epididymal fluid volume, sperm concentration, sperm-motility; fertilization rate and clinical pregnancy rate. There were no significant differences in epididymal fluid and sperm concentration between the two groups. However, the sperm motility in group 1 was significantly higher than that in group 2. The fertilization rates per couple in groups 1 and 2 were 78.2 and 82% (nonsignificant). The pregnancy rate per couple in group 1 was 37.5% (6/16), while that in group 2 was only 5% (1/20); this difference was statistically significant (p < 0.05). Using epididymal sperm for the ICSI procedure, the chances of pregnancy for couples with congenital absence of the vas deferens were significantly higher compared with couples with acquired unreconstructable obstructive male infertility.

Ultrasound stimulation of rat testes damaged by busulfan

The purpose of the present study was to investigate whether or not low-intensity ultrasound exposure (20 mW/cm 2 average intensity) accelerates the repair of rat germinal epithelium damaged by an antispermatogenic agent. The results from analysis of testicular weight and DNA content, sperm production and epididymal sperm concentration showed that the time needed for the reestablishment of the spermatogenic process following busulfan treatment was not reduced by ultrasound energy suggesting that, in contrast to many other mammalian tissues, the seminiferous epithelium is refractory to ultrasound stimulation.

Effects of chronic renal failure on hypothalamo-pituitary-testicular axis function and fertility in rats.

We evaluated the effects of chronic renal failure on hypothalamo-pituitary-testicular axis function in male Wistar rats. Chronic renal failure was induced by five-sixths nephrectomy in male rats. Seven to 10 weeks after the surgery, serum area and creatinine concentrations and hematocrits were evaluated, and human chorionic gonadotropin (hCG) and gonadotropin-releasing hormone (GnRH) tests, and prolactin stimulating and suppression tests were performed. In addition, androgen-binding protein, epididymal sperm content, motility, and fertile potential were assessed. 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 prolactin levels responded appropriately to stimulation and suppression tests. Androgen-binding protein levels, epididymal sperm content, motility, and fertile potential were significantly lower in chronic rats. Chronic renal failure in rats interferes with endocrinologic mechanisms and testicular functions. Thus, uremic rats have a low fertile potential.

Nitrofurazone: reproductive assessment by continuous breeding in Swiss mice.

Nitrofurazone (NTFZ), a nitrofuran antibiotic, was evaluated for reproductive toxicity in Swiss CD-1 mice using the Reproductive Assessment by Continuous Breeding protocol. Male and female mice were cohabited for 15 weeks and exposed to NTFZ in feed at concentrations of 0, 100, 375, and 750 ppm (14-102 mg/kg/day). Fzero 750-ppm breeding pairs had significantly reduced fertility after 7 days of exposure to NTFZ (17% fertile compared to 98% for control pairs) and were infertile after the second litter. Fzero mid-dose pairs had progressively decreasing fertility (47% by the fifth litter), reduced litter size, and reduced proportion of pups born alive. Crossover breeding of control and high-dose Fzero animals confirmed infertility in high-dose males and reduced litter size and pup weight in high-dose females when compared to the control x control group. At necropsy, there were no effects on body weight, but Fzero males had reduced testis weight at the high dose and reduced epididymal sperm concentration and abnormal sperm morphology at all doses of NTFZ. Increased liver as well as kidney and adrenal weights (combined) were observed at 375 and 750 ppm; hepatic hypertrophy was noted microscopically at 750 ppm. Fzero females had reduced body weight, hepatic hypertrophy, and altered estrous cycles at 750 ppm and reduced ovarian weight at all doses. In the second generation, F1 mice at 375 ppm had reduced postnatal survival and body weight and produced smaller F2 litters compared to control mice. At necropsy, F1 males had reduced testes weight and epididymal sperm concentration, abnormal sperm morphology, hepatic hypertrophy at 375 ppm, and borderline nephropathy at 100 and 375 ppm. F1 females had decreased body, liver, and ovarian weight at 375 ppm and altered estrous cycles at 100 and 375 ppm. Thus, NTFZ at > or = 100 ppm (> or = 14 mg/kg/day) caused adverse reproductive effects in Fzero male and female and F1 female mice in the presence of relatively mild systemic toxicity.

Nitrofurazone: Reproductive Assessment by Continuous Breeding in Swiss Mice

Nitrofurazone (NTFZ), a nitrofuran antibiotic, was evaluated for reproductive toxicity in Swiss CD-1 mice using the Reproductive Assessment by Continuous Breeding protocol. Male and female mice were cohabited for 15 weeks and exposed to NTFZ in feed at concentrations of 0, 100, 375, and 750 ppm (14–102 mg/kg/day). F0 750-ppm breeding pairs had significantly reduced fertility after 7 days of exposure to NTFZ (17% fertile compared to 98% for control pairs) and were infertile after the second litter. F0 mid-dose pairs had progressively decreasing fertility (47% by the fifth litter), reduced litter size, and reduced proportion of pups born alive. Crossover breeding of control and high-dose F0 animals confirmed infertility in high-dose males and reduced litter size and pup weight in high-dose females when compared to the control×control group. At necropsy, there were no effects on body weight, but F0 males had reduced testis weight at the high dose and reduced epididymal sperm concentration and abnormal sperm morphology at all doses of NTFZ. Increased liver as well as kidney and adrenal weights (combined) were observed at 375 and 750 ppm; hepatic hypertrophy was noted microscopically at 750 ppm. F0 females had reduced body weight, hepatic hypertrophy, and altered estrous cycles at 750 ppm and reduced ovarian weight at all doses. In the second generation, F1 mice at 375 ppm had reduced postnatal survival and body weight and produced smaller F2 litters compared to control mice. At necropsy, F1 males had reduced testes weight and epididymal sperm concentration, abnormal sperm morphology, hepatic hypertrophy at 375 ppm, and borderline nephropathy at 100 and 375 ppm. F1 females had decreased body, liver, and ovarian weight at 375 ppm and altered estrous cycles at 100 and 375 ppm. Thus, NTFZ at ≥100 ppm (≥ 14 mg/kg/day) caused adverse reproductive effects in F0 male and female and F1 female mice in the presence of relatively mild systemic toxicity.

Effects of alpha-blocker on sperm concentration, motility, intraluminal pressure and fluid movement in the rat cauda epididymis.

To investigate whether alpha blocker has an effect on epididymal sperm parameters, intraluminal pressure and fluid movement. Sprague-Dawley rats were given daily oral doses 1 mg./kg., 2 mg./kg., or 10 mg./kg. of Bunazosin, a selective alpha blocker, for 1 month. A micropuncture technique was used to collect intraluminal fluids. Epididymal sperm concentrations were significantly increased. Progressive motility of spermatozoa was not altered. Intraluminal pressures were significantly reduced, and intraluminal fluid movement rates were significantly increased. Alpha blocker has an effect on sperm transport and storage in the rat testis and epididymis.

Effects of Alpha-Blocker on Sperm Concentration, Motility, Intraluminal Pressure and Fluid Movement in the Rat Cauda Epididymis

Purpose To investigate whether alpha blocker has an effect on epididymal sperm parameters, intraluminal pressure and fluid movement. Materials and Methods Sprague-Dawley rats were given daily oral doses 1 mg./kg., 2 mg./kg., or 10 mg./kg. of Bunazosin, a selective alpha blocker, for 1 month. A micropuncture technique was used to collect intraluminal fluids. Results Epididymal sperm concentrations were significantly increased. Progressive motility of spermatozoa was not altered. Intraluminal pressures were significantly reduced, and intraluminal fluid movement rates were significantly increased. Conclusion Alpha blocker has an effect on sperm transport and storage in the rat testis and epididymis.

Short-term male reproductive toxicity study with sulfasalazine in the rat

Sulfasalazine (2-hydroxy-5-[[4-[(2-pyridinylamino) sulfonyl]phenyl]azo]benzoic acid; SASP) was administered to rats in a short-term male reproductive toxicity study to further examine the utility of this grouping of techniques and to generate reference data with a substance that is known to cause reversible infertility in men. Adult male CD rats (10/group) were orally administered 0, 150, 300, or 600 mg SASP/kg body weight in divided doses for 14 d followed by a 2-week period without treatment. Males were killed on test day (TD) 15 or 29. At each time point, the reproductive system was evaluated by comparing testicular and epididymal weights, DNA ploidy distributions of testicular cell suspensions, testicular and epididymal histopathology, and epididymal sperm concentrations, motion, morphology, and breakage. Adding time as a factor in the protocol aids in distinguishing testicular from posttesticular effects. Changes in sperm quality after 2 weeks of test article administration (TD 15) predominantly reflect effects that occurred after the sperm entered the epididymis, while testicular effects predominated on TD 29. Beginning on TD 14, males to be killed on TD 29 were cohabited with untreated females (1:2). Females were killed at midgestation and examined for pregnancy status. Body weight gain was depressed in all SASP groups during the first 3 d of test article administration. Food consumption was depressed at the 300- and 600-mg/kg dose levels. No changes were seen in testicular weight, but epididymal weight was depressed at the 600-mg/kg dose level. DNA ploidy distributions determined by flow cytometry did not indicate that the kinetics of spermatogenesis were disturbed. However, alterations in sperm release, which have not previously been reported, were seen at all SASP dose levels. On TD 29, the percentage of progressively motile sperm was depressed and beat/cross frequency was increased at the 600-mg/kg dose level. No changes were observed in sperm morphology or breakage. Fertility was slightly depressed at the 600-mg/kg dose level. In this study, testicular histopathology provided the most sensitive endpoint for reproductive toxicity. The impairment of fertility immediately after treatment was stopped, when no changes were apparent in sperm release or sperm motion, suggested that decreased sperm concentrations and altered motility, while contributory, may not be the primary causes of SASP-mediated infertility.

Assessment of the Reproductive Toxicity of a Complex Mixture of 25 Groundwater Contaminants in Mice and Rats

Assessment of the Reproductive Toxicity of a Complex Mixture of 25 Groundwater Contaminants in Mice and Rats. Heindel, J. J., Chapin, R. E., George, J., Gulati, D. K., Fail, P. A., Barnes, L. H., and Yang, R. S. H. (1995). Fundam. Appl. Toxicol. 25, 9-19. The potential reproductive toxicity of a mixture of 25 chemicals (MIX) formulated to simulate contaminated groundwater supplies near hazardous waste dumps was evaluated in CD-1 Swiss mice and Sprague-Dawley rats using the reproductive assessment by continuous breeding protocol. Male and female mice and rats were exposed to MIX in the drinking water at concentrations of 1,5, and 10% of a technically achievable stock solution. For mice, body weight and feed consumption were not affected by MIX but water consumption was decreased for both the 5 and 10% MIX groups in both F 0 and F 1 animals. For F 0 mice, the number of live pups/litter was decreased at 10% MIX and the number of females/litter was decreased 10 and 17% at the mid and high MIX dose, respectively. Vaginal cytology was normal, as were testis weight and testicular spermatid head count. For F 1 mice, fertility was unaffected, but there was a decreased number of female pups/litter (19%) and a decreased adjusted live pup weight at 10% MIX. At necropsy, cauda epididymal sperm concentration and spermatid head count were reduced (20%) in the presence of normal testis, epididymis, prostate, seminal vesicle, liver, and kidney/adrenal weight. Female estrous cyclicity was altered at 5 and 10% MIX with normal kidney/adrenal, uterus, and ovary/oviduct weight. For rats, F 0 body weight and feed consumption were not affected by MIX but water consumption was decreased 10, 30, and 40% in the low-, medium-, and high-dose MIX groups, respectively, and 39% in the high-dose MIX F 1 animals. Rat fertility was normal but there was a decreased number of male pups/litter (11%) and a decreased live pup weight (6%) at 10% MIX. Male and female (F 1) pup weights were decreased on Postnatal Days 0, 4, 7, 14, and 21 (10% MIX) and remained lower through necropsy on Day 120 ± 10. F 1 fertility was normal but F 2 pup weights were decreased (10% MIX). At necropsy, F 1 (10% MIX) male body weight was decreased 16% and relative kidney, testis, epididymis, and prostate weights were increased in the presence of normal sperm concentration percentage motile sperm and percentage abnormal sperm. Estrous cyclicity was normal as were kidney/adrenal and ovary weight while female liver weight was reduced 14%. In summary, a "cocktail" of 25 chemicals commonly found in contaminated groundwater at or near hazardous waste sites was administered in drinking water at doses which resulted in severely decreased water consumption in both mice and rats. Despite the presence, albeit at relatively low concentrations, of many known reproductive toxicants including cadmium, mercury, lead, chloroform, di(2-ethylhexyl)phthalate, and methylene chloride, only minimal reproductive effects were observed in F 0 and F 1 mice and rats.

The anti-progestin CDB 2914 has no antifertility effect in male rats

This study examines the effect of an anti-progestin (CDB 2914) with antiprogestational potencies similar to RU 486 on spermatogenesis, sperm maturation, and fertility in male rats. Adult male rats of proven fertility were administered the anti-progestin (10 mg/kg/day) or vehicle (control group) for 14, 35, and 70 days to study the possible effect of this compound on epididymal sperm maturation, post-meiotic sperm development, spermatogenesis, and fertility, respectively. Fertility rates of the rats were determined by mating studies. The anti-progestin, CDB 2914, had no effect on testis or accessory organ weights, epididymal sperm content or motility, testicular sperm count, spermatogenesis, and fertility of male rats. This study suggests that anti-progestins, when administered even at higher doses than those used in humans, have no contraceptive effect in adult male rats.

Effects of alpha-blocker on daily testicular sperm production and sperm concentration, motility, intraluminal pressure and fluid movement in the rat epididymis.

This study was undertaken to investigate whether alpha-blocker has an effect on daily testicular sperm production and epididymal sperm parameters, intraluminal pressure and fluid movement in the rat cauda epididymal tubules. Sprague-Dawley rats were given daily oral doses 1 mg/kg, 2 mg/kg, or 10 mg/kg of Bunazosin, which was a selective alpha-blocker, for three months. Intraluminal fluids were collected from the cauda epididymidis using a micropuncture technique. Sperm concentration was determined with a sperm concentration microassay. Motility estimates were made by measurements of linear distance traveled by sperm in the diluent. Epididymal intraluminal pressure was measured through a micropunctured pipette connected to a micropressure transducer. Intraluminal fluid movement was examined by measurement of the distance which Sudan Black stained mineral oil moved along the epididymal tubules. Outside diameters of seminiferous and epididymal tubules were measured by light microscopy. Epididymal sperm concentrations were significantly increased after administration of alpha-blocker. Progressive motility of spermatozoa was not significantly altered by alpha-blocker. Intraluminal pressures were significantly reduced and intraluminal fluid movement rates were significantly increased by alpha-blocker. Daily sperm production was significantly increased by alpha-blocker. Outside diameters of seminiferous and epididymal tubules were significantly distended when treated with alpha-blocker. These results demonstrate that alpha-blocker has an effect on spermatogenesis and sperm transport in the rat testis and epididymis.

Bilateral effect of unilateral vasectomy on testicular testosterone biosynthesis

Tweive immature male dogs underwent a left vasectomy (group A). An additional five underwent a sham operation (group B). Sixteen weeks after the surgery, the bilateral mean values for caudal epididymal sperm content, the percentage of motile spermatozoa, intratesticular testosterone concentration, and testicular secretion of androgen-binding protein (in vitro) were significantly lower in group A. The mean peripheral serum testosterone responses 3 hours after human chorionic gonadotropin stimulation (3,000 IU) were significantly lower in group A than in group B (6.3 ng/mL v 9.5 ng/mL). These findings indicate a bilateral deficiency in both Leydig and Sertoli cell secretory function in unilaterally vasectomized dogs, resulting in impaired bilateral spermatogenesis and sperm maturation. The authors suggest that unilateral injuries of the vas deferens during hernia operations in children may result in bilateral testicular dysfunction.

Assessment of the Reproductive and Developmental Toxicity of Pesticide/Fertilizer Mixtures Based on Confirmed Pesticide Contamination in California and Iowa Groundwater

Assessment of the Reproductive and Developmental Toxicity of Pesticide/Fertilizer Mixtures Based on Confirmed Pesticide Contamination in California and Iowa Groundwater. Heindel, J. J., Chapin, R. E., Gulati, D. K., George, J. D., Price, C. J., Marr, M. C., Myers, C. B., Barnes, L. H., Fail, P. A., Grizzle, T. B., Schwetz, B. A., and Yang, R. S. H. (1994). Fundam. Appl. Toxicol. 22, 605-621.Pesticides and fertilizers, as used in modern agriculture, contribute to the overall low-level contamination of groundwater sources. In order to determine the potential of pesticide and fertilizer mixtures to produce reproductive or developmental toxicity at concentrations up to 100X the median level found in groundwater, we prepared and studied two mixtures of pesticides and a fertilizer (ammonium nitrate). One mixture containing aldicarb, atrazine, dibromochloropropane, 1,2-dichloropropane, ethylene dibromide, and simazine plus ammonium nitrate was considered to be a representative of groundwater contamination in California (CAL). The other, containing alachlor, atrazine, cyanazine, metolachlor, metribuzin, and ammonium nitrate, simulated groundwater contamination in Iowa (IOWA). Each mixture was administered in the drinking water of either Swiss CD-1 mice during a Reproductive Assessment by Continuous Breeding study or pregnant Sprague-Dawley rats (gd 6-20) at three dose levels (1×, 10×, and 100×) where 1× was the median concentration of each pesticide component as determined in the groundwater surveys in California or Iowa. Unlike conventional toxicology studies, the purpose of this study was to evaluate the health effects of realistic human concentrations. Thus, the testing concentrations are probably well below the maximally tolerated dose. Propylene glycol was used as the solubilizer for the pesticides in drinking water formulations in both studies. In the reproductive study, neither mixture caused any clinical signs of toxicity, changes in food or water consumption, or body weight in either F0 or F1 mice at doses up to 100× the median groundwater concentrations. There were no treatment-related effects on fertility or any measures of reproductive performance of either the F0 or the F1 generation mice exposed to either CAL or IOWA at up to 100×. Similarly, measures of spermatogenesis, epididymal sperm concentration, percentage motile sperm, percentage abnormal sperm, and testicular and epididymal histology were normal. In the developmental study, CAL- or IOWA-exposed females did not exhibit any significant treatment-related clinical signs of toxicity. No adverse effects of CAL or IOWA were observed for measures of embryo/fetal toxicity, including resorptions per litter, live litter size, or fetal body weight. CAL or IOWA did not cause an increased incidence of fetal malformations or variations. In summary, administration of these pesticide/fertilizer mixtures at levels up to 100-fold greater than the median concentrations in groundwater supplies in California or Iowa did not cause any detectable reproductive (mice), general, or developmental toxicity (rats).

Utilization of a short-term male reproductive toxicity study design to examine effects of α-chlorohydrin (3-chloro-1,2-propanediol)

α-Chlorohydrin (ACH) was administered to rats in a short-term male reproductive toxicity study to examine the usefulness of the method and to provide reference data with a substance that is known to elicit adverse effects on both sperm production and sperm quality within or following a 2-week treatment period. Adult male CD rats (10 per group) were administered ACH orally by gavage at doses of 0, 1, 5, or 25 mg/kg/day for 14 days. Males were killed on Test Day (TD) 15 or 29. A 2-week period without treatment was included to distinguish between testicular and posttesticular effects. At each time point, the reproductive system was evaluated by comparing testes weight, DNA ploidy distributions of testicular cell suspensions, testicular and epididymal histopathology, and epididymal sperm concentration, motility, morphology, and breakage. Beginning on TD 14, males to be killed on TD 29 were cohabited with untreated females (1:2). Females were killed on Gestation Day 13 and examined for pregnancy status. During the treatment period, minor depressions in body weight and relative food consumption occurred in rats administered 25 mg/kg ACH. Testicular and epididymal lesions also occurred at this dose level. DNA ploidy distributions determined by flow cytometry were predictive of testicular damage, with effects more pronounced on TD 29 than on TD 15. The preparation methods used selected for the most motile and vigorous population of epididymal sperm. Sperm motion was altered at the 5- and 25-mg/kg dose levels on TD 15. The percentage of motile sperm and the percentage of progressively motile sperm were markedly depressed at both the 5- and 25-mg/kg dose levels where antifertility effects occurred. Sperm velocities and amplitude of lateral head displacement were depressed at the 25-mg/kg dose level on both TD 15 and 29. Additionally, decreased epididymal sperm concentrations and increased breakage were recorded at this dose level. The findings in this study are consistent with the scientific literature for ACH and demonstrate posttesticular effects on epididymal sperm and delayed expression of testicular lesions. They also support the use of this methodology for an initial assessment of male reproductive effects.

Testicular and epididymal sperm content in grazing Cashmere bucks: seasonal variation and prediction from measurements in vivo

Each month, for 15 months, the testes and epididymides were recovered from five Australian cashmere bucks selected at random from a group of mature bucks (initial n = 116) at pasture (location 29 degrees S, 153 degrees E). The extent of seasonal change in testicular and epididymal sperm reserves was determined and indirect methods for predicting these reserves were developed. Paired testicular weight exhibited clear seasonal variation from 137 g in August to 269 g in February. The total elongated spermatid content of the testes, determined by homogenization, showed a very similar seasonal pattern, ranging from 13.8 x 10(9) in September to 36.2 x 10(9) in March. Seasonal changes of similar timing were observed for paired epididymal weight and sperm content. Although changes in total testicular spermatid content were largely the result of change in testicular weight (R2 = 0.72, P < 0.001), the elongated spermatid content of testicular parenchyma (mean, 127 x 10(6) g-1) exhibited significant seasonal variation with elevated values between February and June, suggestive of an increase in the efficiency of spermatogenesis. Daily sperm production, calculated by means of a spermatogenic time divisor for sheep, ranged from 2.76 x 10(9) in September to 7.23 x 10(9) in February. Scrotal circumference, scrotal volume and testicular length x diameter2 were identified as accurate predictors of testicular weight (R2 > or = 0.87) and sperm content (R2 > or = 0.70). The results demonstrate that: (a) cashmere bucks exhibit considerable seasonal variation in spermatogenesis associated primarily with changes in testicular mass but also with changes in the efficiency of spermatogenesis; and (b) indirect measures of testicular size are good predictors of testicular elongated sperm content. When the correct spermatogenic time divisor for goats is determined, such indirect measures may be used to predict daily sperm production.

Microassay of sperm concentration in the rat epididymis by micropuncture technique.

Micropuncture samples taken from the rete testis, caput, corpus and cauda epididymidis of adult rats were assayed for intraluminal sperm concentrations. The amount of fluid resorbed from the efferent duct and epididymal lumen was calculated based on the sperm concentration. Epididymal sperm concentrations increased from the rete fluid to the cauda fluid through the caput fluid. Eighty-nine percent of the fluid leaving the rete testis is resorbed by the efferent ducts and proximal epididymal tubule, and 96% of the fluid leaving the rete testis is resorbed in the distal cauda epididymidis. Resorption is important for the control of intraluminal fluid by the epididymis.