[Studies on ejaculation. 3. The nervous pathways controlling seminal emission and closure of the internal urethral orifice during ejaculation].
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Accessory sex gland and excurrent duct activity of 10 stallions was visualized with transrectal ultrasonography during seminal emission and ejaculation. First and last penile urethral contractions were defined as the start (0 sec) and end of ejaculation, respectively. Duration of ejaculation (n = 63 ejaculations) averaged 6.15 +/- 2.98 sec. Penile urethral contractions occurred an average of 6.2 +/- 2.2 times per ejaculation. Right bulbourethral glands (n = 19 ejaculations) alternated repeatedly from ovoid to flattened, irregular shapes during ejaculation. Cross-sectional area of right bulbourethral glands did not change (p > 0.40) between 3 sec before ejaculation and the end of ejaculation. Cross-sectional area of right prostatic lobes (n = 17 ejaculations) decreased (p < 0.01) between 3 sec before ejaculation and the end of ejaculation, with decreases (p < 0.05) at 2, 1, and 0 sec before ejaculation and at the time of the second penile urethral contraction. Excurrent ducts of ampullae (n = 17 ejaculations) first appeared to dilate with fluid at 2.60 +/- 0.23 sec before ejaculation and subsequently dilated an average of 3.4 +/- 0.3 times between 3 sec before ejaculation and the end of ejaculation. Fifty-three of 58 (93%) ampullar duct dilations occurred prior to the start of ejaculation. During each dilation of ampullar ducts, fluid remained visible for 0.23 +/- 0.04 sec. Fluid was detected within the lumina of vesicular gland excurrent ducts during the 6 of 17 monitored ejaculations that produced detectable gel.(ABSTRACT TRUNCATED AT 250 WORDS)
Modifications of semen quality related to ejaculation frequency is one of the most important and neglected factors from the standpoint of artificial insemination or sperm competition. New Zealand white rabbits (Oryctolagus cuniculus) offer an advantageous experimental model because they have characteristic sexual behavior, they present rapid ejaculation after a single intromission, they have a very short interval between successive ejaculations, and semen can be easily collected. The authors studied the modifications on sperm quality (semen volume, sperm concentration, sperm motility) produced by 14 consecutive ejaculations recovered every 15 min using stimulus females and an artificial vagina. Bucks were exposed every 15 min to a sexually receptive female. After each ejaculation the female was removed and reintroduced 15 min later. Sperm concentration showed a clear biphasic conduct. The amount of spermatozoa per milliliter decreased rapidly until ejaculate number 6, showed a highly significant increase in ejaculates 7-9, and decreased to nil in the last 2 ejaculates. Total number of ejaculated spermatozoa was 557 x 10(6), 76% of which were recovered from the first 4 ejaculates. Ejaculate volume also showed a biphasic conduct. In the first ejaculates the volume decreased linearly until ejaculate number 6, showed a significant increase in ejaculates 7-10, and then decreased. The total semen volume recovered during the experiment was 2.44 mL, 40% of which (0.98 mL) was recovered from the first 2 ejaculates. Individual motility in the first 6 ejaculates was preferentially progressive (60% of the sperms) and turned to random or in situ from the seventh ejaculate up. The proportion of spermatozoa with cytoplasmic droplets increased from ejaculates 6 and 7 up. The results seem to reflect an acceleration of semen transport through the epididymis when the demands for spermatozoa increase.
The Gulf Coast Native sheep, or Louisiana Native sheep, is an endangered previously feral domestic sheep population of European origin that has been under natural selection pressure for reproductive survival in their transplanted range while roaming in the southern Gulf Coast Region of the United States. This sheep population has an increased natural resistance to internal parasites, breeds year-around and has a greater percentage of live lambs as compared with other breeds of sheep raised in similar environments. To preserve the genetic diversity of this important feral sheep population, semen was collected by electro-ejaculation and subjected to cryopreservation for subsequent storage in a genome resource bank. Unrelated rams (n=5) were collected 3 days-a-week, allowing at least 2 days of rest between collections. Two ejaculates were obtained from each ram per collection day, with the second collection conducted 10min after the first ejaculation. Semen was processed using the standard Salamon cryopreservation procedure in a Tris-yolk-glycerol extender, frozen in 0.5ml plastic straws using liquid nitrogen (LN(2)) vapor and stored in LN(2). Each ejaculate was evaluated for volume, sperm concentration/ml (x10(9)/ml), number of spermatozoa/ejaculate (x10(9)), sperm progressive motility (%) for pre-cooled semen, cooled semen and semen after thawing. For the five rams, each semen variable for the first ejaculate was compared with that of the second ejaculate collected 10min later. The mean semen volume, sperm concentration and number of spermatozoa per ejaculate obtained from the first ejaculate were significantly greater (P< or =0.01) than those of the second ejaculate (comparisons being 1.62 and 1.06; 3.2 and 1.5; 5.4 and 1.8, respectively). Overall, the mean motility of pre-cooled (22 degrees Celsius), cooled (5 degrees Celsius) and frozen (-196 degrees Celsius) post-thawed spermatozoa was less (P< or =0.01) in the first ejaculate (71.5, 64.8 and 34.1%, respectively) compared with that of the second ejaculate (75, 72.4 and 44.1%, respectively). Conversely, no differences were detected in loss in the percent progressive motility of sperm from cooled sperm to post-thaw sperm from the first and second ejaculates. In summary, our findings suggest sperm collected during the second ejaculate 10min after the first ejaculate of rams survives thawing with a greater rate of progressive motility than that of the first ejaculate. The ability to collect two consecutive ejaculates in a short period by electro-ejaculation could be valuable for gamete resource banking and preserving genetic diversity of the Gulf Coast Native sheep.
Depression is a common cause of sexual dysfunction, but also antidepressant medication is often associated with sexual side effects. This article includes two related studies. The first double-blind, placebo-controlled study was conducted in men with lifelong rapid ejaculation and aimed to assess putative differences between the major selective serotonin reuptake inhibitors (SSRIs) (fluoxetine, fluvoxamine, paroxetine, and sertraline) with regard to their ejaculation-delaying effect. Sixty men with an intravaginal ejaculation latency time (IELT) of 1 minute or less were randomly assigned to receive fluoxetine 20 mg/day, fluvoxamine 100 mg/day, paroxetine 20 mg/day, sertraline 50 mg/day, or placebo for 6 weeks. During the 1-month baseline and 6-week treatment periods, the men measured their IELT at home using a stopwatch. The trial was completed by 51 men. During the 6-week treatment period, the geometric mean IELT in the placebo group was constant at approximately 20 seconds. Analysis of variance revealed a between-groups difference in the evolution of IELT delay (p = 0.0004); in the paroxetine, fluoxetine, and sertraline groups there was a gradual increase to about 110 seconds, whereas in the fluvoxamine group, IELT was increased to only approximately 40 seconds. The paroxetine, fluoxetine, and sertraline groups differed significantly (p < 0.001, p < 0.001, p = 0.017, respectively) from placebo but the fluvoxamine group did not (p = 0.38). Compared with baseline, paroxetine exerted the strongest delay in ejaculation, followed by fluoxetine and sertraline. There was no clinically relevant delay in ejaculation with fluvoxamine. In men with lifelong rapid ejaculation, paroxetine delayed ejaculation most strongly, whereas fluvoxamine delayed ejaculation the least. The second double-blind, placebo-controlled study was carried out in men with lifelong rapid ejaculation (IELT < or = 1 minute) and in men with lifelong less-rapid ejaculation (IELT > 1 minute) to investigate whether data about SSRI-induced delayed ejaculation in men with rapid ejaculation may be extrapolated to men with less-rapid ejaculation. After measurement of IELT at home (using a stopwatch) during a 1-month baseline assessment, 32 men with an IELT of 1 minute or less (group 1) or more than 1 minute (group 2) were randomly assigned to receive paroxetine 20 mg/day or placebo for 6 weeks in a double-blind manner. Patients continued to measure their IELTs at home during the 6 weeks of the study. At baseline, 24 patients consistently had IELTs of one minute or less (group 1), and eight patients had IELTs of more than 1 minute (group 2). The geometric mean IELT was 14 seconds in group 1 and 83 seconds in group 2. Twelve patients in group 1 and five in group 2 were randomized to the paroxetine 20 mg/day. The percentage increase in the geometric mean IELT compared with baseline in patients treated with paroxetine was 420% (95% confidence interval [CI], 216-758%) in group 1 and 480% (95% CI, 177-1,118%) in group 2 (p = 0.81). After 6 weeks of treatment with paroxetine, the geometric mean IELT was 92 seconds in group 1 and 602 seconds in group 2 (p < 0.001). Therefore, the paroxetine-induced percentage increase in IELT seems to be independent of the baseline IELT. This suggests that ejaculation-delaying side effects of some SSRIs investigated in men with lifelong rapid ejaculation may be generalized to men with less-rapid ejaculation.
Ejaculation is a reflex mediated by a spinal control center, referred to as a spinal ejaculation generator. This spinal ejaculation generator coordinates sympathetic, parasympathetic and motor outflow to induce the two phases of ejaculation, i.e., emission and expulsion. In addition, the spinal ejaculation generator integrates this outflow with inputs that are related to the summation of sexual activity prior to ejaculation that are required to trigger ejaculation. Recently, a group of spinothalamic neurons in the lumbar spinal cord (LSt cells) were demonstrated to comprise an integral part of the spinal ejaculation generator. Specifically, lesions of LSt cells completely ablate ejaculatory function. Moreover, LSt cells are activated following ejaculation, but not following other components of sexual behavior. Furthermore, based on their relationship with autonomic nuclei, motoneurons and genital sensory inputs, LSt cells are also in the ideal anatomical position to integrate sensory inputs and autonomic and motor outflow. Additionally, the spinal ejaculation generator is under inhibitory and excitatory influence of supraspinal sites, including the nucleus paragigantocellularis (nPGi), the paraventricular nucleus of the hypothalamus (PVN) and the medial preoptic area (MPOA). Finally, sensory information related to ejaculation is processed in the spinal cord and brain, possibly contributing to the rewarding properties of ejaculation. One candidate pathway for relay of ejaculation-related cues consists of LSt cells and their projections to the parvocellular subparafascicular thalamic nucleus. Moreover, neural activation specifically related to ejaculation is observed in the brain and may reflect of processing of ejaculation-related sensory cues.
This study is a part of our ongoing work toward developing pharmacological methods for enhancing and inducing ejaculation in stallions with ejaculatory dysfunction. We evaluated a combination treatment of imipramine hydrochloride followed 10 minutes later by xylazine hydrochloride for the induction of ex copula ejaculation. Eight pony stallions each underwent 6 treatment trials conducted at 4-day intervals. The trials were conducted in the animals' stalls, where they were observed for 90 minutes following treatment. To evaluate the effect of pretreatment sexual stimulation on the rate of ejaculation for each of the 8 stallions, 3 of the 6 trials were preceded by exposure to a restrained ovariectomized pony mare. For 7 of the 8 stallions, 1 to 4 of the 6 trials resulted in induced ejaculation, for a total of 16 ejaculations in the 48 trials. Six of the ejaculations occurred with imipramine treatment alone, before the administration of xylazine. All ejaculations were associated with erection and masturbation. Six of 24 trials (25%) preceded by sexual stimulation resulted in ejaculation, while 10 of 24 trials (42%) without sexual prestimulation resulted in ejaculation. These proportions were not different (P = 0.11). Induced ejaculates were collected into a plastic bag positioned over the prepuce by a girth strap for the comparison of semen characteristics with 2 base line ejaculates obtained in copula from these stallions during the week preceding the series of induced ejaculation trials (with similar 4-day intervals from previous ejaculation). The induced ejaculates were of lower total volume, higher concentration, lower gel volume, higher total numbers of spermatozoa, and lower pH (P < 0.05) than the base line in copula ejaculates. Together, these semen characteristics suggest increased emission of the sperm-rich fraction and reduced emission of accessory gland fluids, probably resulting from imipramine treatment.
This study evaluated the percentage of Y-chromosome bearing spermatozoal (%Y-CBS) variation from ejaculates within individual males using two experiments. In the first experiment, six ejaculates were taken from each of five sexually rested (>30 days) Holstein bulls. Ejaculates were processed separately and stored in liquid nitrogen. From each ejaculate, five straws were thawed and equal sperm number, pooled samples were constructed using hemacytometer counts. Individual ejaculate DNA samples were extracted and quantified by spectroscopy. AY-chromosome specific segment was amplified by polymerase chain reaction (PCR) and the product separated by gel electrophoresis. Ethidium bromide stained bands were detected by image analysis and equated to a 50 %Y-CBS pool. In the second experiment (91 days), two ejaculates were collected from sexually rested (>21 days) bulls weekly and two ejaculates were collected from bulls every 21 days. Specific Y-chromosome (SRY) and X-chromosome (factor IX, F9) sperm DNA was amplified by PCR and the products separated by gel electrophoresis. Ethidium bromide stained bands were detected by image analysis and compared to a standard curve constructed from pure SRY and F9 PCR product. The log ratio (SRY/F9) of the corrected intensity densities were used to estimate the percent Y-chromosome DNA bearing spermatozoa (%Y-CDBS) in each ejaculate using inverse regression procedures. In Experiment 1, ejaculate differences for the first collection ranged from 17 to 71 %Y-CBS. Differences remained large for the second ejaculates and lessened for the third and fourth collections. Differences were least for the last two collections. Sperm head area also fluctuated. In Experiment 2, collection frequency affected the pattern of %Y-CDBS response. In bulls collected weekly, %Y-CDBS changed in a sinusoid fashion with a period of about 13.5 days. For bulls collected on a 21-day interval, %Y-CDBS ejaculate differences were high in the first ejaculate after sexual rest. Maximization of %Y-CDBS variation between ejaculate and its identification by PCR would allow ejaculate selection to be used to the alter the sex ratio in producers' calf crops.
OBJECTIVES: Measurement of total serum prostate-specific antigen (PSA) is widely used as an aid to early detection of prostate cancer. Measurement of the ratio of free to total PSA may increase the specificity of PSA testing. To improve specificity further, other factors that may cause transient increases in PSA, such as ejaculation, have been identified. We prospectively studied the effect of ejaculation on total and free PSA levels and examined whether changes induced by ejaculation would affect recommendations for performing prostatic biopsy. METHODS: We measured the baseline total and free serum PSA levels and obtained measurements 1.6, and 24 hours after ejaculation in 20 volunteers (mean age 59 years). All men had baseline PSA levels less than 4.0 ng/mL. We used repeated-measures analysis of variance to test for changes in total, free, and percent free PSA after ejaculation. We also calculated the proportion of men with PSA levels greater than the expected biologic variability at each timepoint. RESULTS: The mean total, free, and percent free serum PSA increased 1 hour after ejaculation. Mean total PSA levels remained significantly increased 6 and 24 hours after ejaculation. Mean free PSA decreased to baseline levels by 6 hours after ejaculation, and percent free PSA returned to baseline by 6 hours after ejaculation and then decreased below baseline by 24 hours. When normal biologic variation was accounted for, 40% of men, at 24 hours after ejaculation, had total PSA levels above the baseline level. Similarly, 24 hours after ejaculation, the percent free PSA remained above baseline level in 10% and below baseline level in 35% of the men. CONCLUSIONS: Both total and free PSA increase immediately after ejaculation, with differing rates of return to baseline levels. PSA testing within 24 hours after ejaculation may lead to an erroneous interpretation of the results of both total and percent free PSA measurements in a small proportion of men.
OBJECTIVES: To determine the effect of ejaculation on the serum prostate-specific antigen (PSA) concentration in men at risk for developing prostate cancer. METHODS: A prospective, community-based study was conducted in which 64 men, aged 49 to 79 years, underwent a serum PSA determination immediately before ejaculation (baseline) and at 1 hour, 6 hours, and 24 hours following ejaculation. The serum PSA also was measured 48 hours and 1 week after ejaculation if the concentration had not returned to the baseline value by the previous time interval. All subjects abstained from ejaculation for a minimum of 7 days prior to the study and until the PSA concentration returned to the baseline level. Absolute and relative change in serum PSA concentration, as well as the time to return to baseline PSA concentration following ejaculation, were assessed. RESULTS: The serum PSA concentration increased following ejaculation in 87% of the subjects. The mean baseline PSA was 1.8 ng/mL (median, 0.7 ng/mL). The mean absolute PSA change +/- standard deviation 1 hour, 6 hours, 24 hours, and 48 hours after ejaculation was 0.8 +/- 1.32 ng/mL, 0.3 +/- 0.66 ng/mL, 0.2 +/- 0.33 ng/mL, and 0.4 +/- 0.40 ng/mL, respectively. The mean relative PSA change +/- standard error 1 hour, 6 hours, 24 hours, and 48 hours after ejaculation was 41 +/- 4%, 9 +/- 1.5%, 8 +/- 1.3%, and 10 +/- 2.3%, respectively. The absolute and relative changes in PSA concentration noted 1 hour, 6 hours, and 24 hours after ejaculation were statistically significant (P = 0.0001). A strong correlation was observed between absolute change in PSA and baseline serum PSA, at each time interval (1 hour: r = 0.68, 6 hours: r = 0.77, 24 hours: r = 0.70; P < 0.0001) after ejaculation. Similarly, a significant correlation was noted between absolute change in PSA and patient age at each time interval (1 hour: r = 0.37, 6 hours: r = 0.38; P = 0.002, 24 hours: r = 0.55; P < 0.0001). Ninety-two percent of subjects returned to baseline by 24 hours (95% confidence interval (Cl) = 83% to 97%), whereas 97% of subjects returned to baseline by 48 hours (95% Cl = 89% to 99%). CONCLUSIONS: Ejaculation causes a significant increase in the serum PSA concentration in men between 49 and 79 years of age that may persist for up to 48 hours. This change appears to correlate with age and baseline PSA. It is recommended that men abstain from ejaculation for 48 hours prior to having a serum PSA determination.
OBJECTIVES: To determine the prevalence and importance of pain/discomfort on ejaculation (prostatitis-like symptom) in men with lower urinary tract symptoms (LUTS) diagnosed with clinical benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: Baseline data from 5096 men reporting LUTS suggestive of BPH, and enrolled in the ALF-ONE study by general practitioners and urologists in Europe, Asia, Latin America, the Middle East and Canada, were analysed to determine the prevalence and significance of pain/discomfort on ejaculation. All the men were asked to complete the International Prostate Symptom Score (IPSS) questionnaire, the bother score (IPSS question 8), and the Danish Prostate Symptom Score sexual-function questionnaire (DAN-PSSsex) which assesses three symptoms (rigidity of erection, amount of ejaculate and pain/discomfort on ejaculation) and their bothersomeness. RESULTS: There were 3700 sexually active men who had an evaluable answer to the DAN-PSSsex question related to pain/discomfort on ejaculation. Of these, 688 (18.6%) reported pain/discomfort on ejaculation and 609 (88%) considered it was a problem. Patients with painful ejaculation had more severe LUTS and reported greater bother (P < 0.001). Of men with painful ejaculation, 72% reported erectile dysfunction, of whom 91% considered it a problem, and 75% reported reduced ejaculation, of whom 81% considered it a problem. By contrast, of men with no ejaculatory discomfort, 57% reported erectile dysfunction, of whom 79% considered it a problem, and 56% reported reduced ejaculation, of whom 57% considered it a problem. A history of urinary tract infection was reported by 12% of men in the ejaculatory pain group, compared with 7% in the LUTS-only group, while 5% of men in the ejaculatory pain group reported macroscopic haematuria, compared to 3% in the LUTS-only group. Men with ejaculatory pain were slightly younger, but there were no significant differences in duration of LUTS, history of acute urinary retention, prostate-specific antigen concentrations or maximum urinary flow rate compared to the LUTS-only group. CONCLUSIONS: Of sexually active men with LUTS suggestive of BPH, approximately 20% complain of specific prostatitis-like symptoms of pain/discomfort on ejaculation, and these men clearly differ from those who present with LUTS only. For most the symptom is a significant bother. Men with BPH and painful ejaculation have more severe LUTS and reported greater bother, and had a higher prevalence of erectile dysfunction and reduced ejaculation, than men with LUTS only. Evaluation and treatment strategies should address this population of men with symptoms suggestive of both prostatitis and BPH.
PURPOSE: We assessed the impact of intermittent tamsulosin treatment on abnormal ejaculation. MATERIALS AND METHODS: This prospective study was performed between January 2001 and December 2004. It included 405 patients who were at least 50 years old with lower urinary tract symptoms. This study was divided into 2 phases. In phase 1 patients received a 0.4 mg tamsulosin capsule daily after breakfast for at least 3 months. The second phase of this study was performed in the 30 patients with abnormal ejaculation. In this phase these patients received 0.4 mg tamsulosin once daily every other day. Patients were assessed at study entry and at study week 6. RESULTS: Abnormal ejaculation was reported as retrograde ejaculation by 18 patients, as decreased volume by 7 and as absent ejaculate by 5. Ejaculatory function recovered during intermittent tamsulosin treatment in 12 patients with retrograde ejaculation and in 7 with decreased volume or absent ejaculate. As a result, 19 of 30 patients (63.3%) with abnormal ejaculation recovered. A significant improvement in retrograde ejaculation was found after intermittent tamsulosin treatment (p = 0.02). Although there were improvements in decreased volume or absent ejaculate at week 6 of intermittent treatment, these differences were not statistically significant (p = 0.42 and 0.61, respectively). CONCLUSIONS: The results of the current study, which to our knowledge is the first report of the effect of intermittent tamsulosin treatment on abnormal ejaculation, show that this treatment modality is well tolerated and provides comparable improvements for abnormal ejaculation.
For successful fertilization, a functionally constituted sperm plasma membrane is necessary, and this is clearly dependent on the sperm maturation process. The latter involves a series of complex changes which result from a sequence of events occurring at different points within the epididymis. The transit time through the epididymis can be influenced by external factors such as sexual stimulus and ejaculatory frequency. The present work was undertaken to determine changes in ram sperm viability and other sperm quality characteristics in relation to ejaculatory frequency. Three successive ejaculates were collected from rams during three different abstinence periods (collected every day, every 2 days and every 3 days). Cell viability (membrane integrity determined by fluorescence staining), progressive individual motility, and other in vitro parameters of sperm quality were evaluated. Second ejaculates showed the highest cell viability of the three periods studied, and increased as the abstinence period lengthened. The maximum proportion of viable cells (average 60%) was obtained in the second ejaculate after an abstinence period of 3 days. Likewise, overall and progressive individual motilities were higher in second ejaculates, the maximum value being 70% after 3 days of abstinence. The percentage of damaged or acrosome-reacted spermatozoa was greater after 1 day of abstinence than after the other periods analysed, whereas the first ejaculate showed the highest value in all periods. Differences in ejaculate volume were correlated strongly with both variables considered (abstinence period and ejaculate number). In the third ejaculate, about 27% more volume was obtained after 3 days of abstinence than after abstinence for 1 or 2 days. Sperm concentration increased significantly as the abstinence period lengthened, and also decreased significantly with ejaculate number in all cases. Therefore, the total number of spermatozoa in the ejaculate was clearly dependent on the abstinence period and the ejaculate number. In conclusion, the results obtained suggest that using the second and/or a mixture of second and third ejaculates would improve the results in artificial insemination and in fertility studies. In addition, the use of better quality semen would facilitate progress in semen cryopreservation studies.