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PubMed1998

Live mice from cryopreserved embryos derived in vitro with cryopreserved ejaculated spermatozoa.

This study was undertaken to try to reduce the number of animals required to maintain mouse strains by banking of embryos or spermatozoa. The principal objective was to cryopreserve ejaculated mouse spermatozoa, using a method recently developed for epididymal spermatozoa. Within 30 min after mating, ejaculated spermatozoa were flushed from the uterus of mated females; shortly afterwards, epididymal spermatozoa were also collected from the same males that had mated with the females. The average values for spermatozoal motility and viability of ejaculated specimens of nine males were 43 and 46%, respectively, and for epididymal specimens, the corresponding values were 60 and 52%. In experiment 1, ejaculated or epididymal spermatozoa were incubated with oocytes for 0.5 to 4 h. As evidenced by development into two-cell embryos within 24 h, kinetics of fertilization of the two spermatozoa types were similar. In experiment 2, ejaculated and epididymal spermatozoa of three males were separately cryopreserved in medium containing raffinose, glycerol, and egg yolk. Samples were cooled and seeded at -4 degrees C, cooled to -70 degrees C at 20 degrees C/min, and then were placed into liquid nitrogen for storage. When cryopreserved epididymal or ejaculated spermatozoa were thawed at > 1,000 degrees C/min and used for in vitro fertilization, > 60% of oocytes cleaved, and approximately 95% of cleaved embryos developed into morulae or blastocysts. When embryos produced with cryopreserved spermatozoa were transferred into recipients, 18 and 22 live pups were obtained from 62 and 54 embryos resulting from ejaculated or epididymal spermatozoa, respectively. This study documented the feasibility of cryopreserving ejaculated spermatozoa as an effective alternative to preserving germ plasm from genetically valuable mice.

Animals↗
PubMed1975

Influence of ejaculation frequency of stallions on characteristics of semen and output of spermatozoa.

Approximately 1 week was required to stabilize the extragonadal sperm reserves in stallions ejaculated daily for 10 weeks. The true daily sperm output of a stallion was equal to the mean daily sperm output of seven ejaculates +/- 1-35 X 10(9) spermatozoa. Mean concentrations of spermatozoa/ml and number of spermatozoa/ejaculate were higher (P less than 0-01) for X1 and X3/week ejaculation frequencies than for a X6/week frequency. Sperm output/week was nearly identical for a X6/week frequency. Sperm output/week was nearly identical for the X3 and X6 frequencies and higher (P less than 0-01) than the X1 frequency. Increase of ejaculation frequency from one to two ejaculates/day twice weekly significantly (P less than 0-01) raised the output of spermatozoa/week. Gel-free semen volume, spermatozoa/ml, and number of spermatozoa/ejaculate were higher (P less than 0-01) in the first, than in the second, ejaculate. Collection of semen on alternate days would be a practical ejaculation frequency for inseminating mares. Two ejaculates collected twice a week would be a practical ejaculation frequency for long-term storage of stallion semen.

Animals↗
PubMed1979

Disappearance of spermatozoa from the ejaculates of geldings.

Twenty-three geldings were used to determine changes in seminal characteristics following castration and the effect of frequency of ejaculation on these seminal characteristics. In Exp. 1, semen was collected from 8 geldings every other day after castration until the number of spermatozoa per ejaculate was below 1% of the precastration value. An average of 3 ejaculates was required to reduce the number of spermatozoa below this level. In Exp. 2, 15 stallions were castrated and each stallion was assigned to 1 of 3 groups for seminal collection at 7, 14 or 21 days post-castration. The ejaculates collected on these days contained an average of 23, 14 and 2 X 10(6) spermatozoa/ejaculate, respectively. In both experiments, all spermatozoa in ejaculates collected 7 or 8 days after castration were non-motile. Frequency of ejaculation did not appear to hasten the disappearance of spermatozoa from the ejaculates. It is considered that after castration several months may be required before the ampulla and vas deferens become devoid of spermatozoa and the ejaculates azoospermic, and that pregnancy is unlikely to result from mating or insemination 1 week after castration.

Animals↗
PubMed1994

Effect of seminal plasma on motion characteristics of epididymal and ejaculated stallion spermatozoa during storage at 5 degrees C.

The objective of this experiment was to examine the effect of seminal plasma on motion characteristics of epididymal and ejaculated equine spermatozoa during storage at 5 degrees C. Epididymal spermatozoa were flushed with either seminal plasma or a skim milk-glucose extender. Ejaculated spermatozoa were collected with extender added 10 minutes after semen collection and addition of extender during ejaculation by placing 50 ml extender in the collection bottle. Semen samples were centrifuged and resuspended with a skim milk-glucose extender containing seminal plasma (0, 5 and 25%; v/v), prepared from pooled ejaculates from the semen donors. The percentage of motile spermatozoa and the average path velocity were evaluated by computerized semen analysis before and after centrifugation as well as after 24 and 48 h of cooled storage (5 degrees C). In epididymal samples flushed with seminal plasma versus extender, percentage of motile spermatozoa and spermatozoal velocity ws significantly higher before and after centrifugation but not at 24 and 48 h of cooled storage. Method of semen collection did not influence motility of ejaculated spermatozoa before centrifugation. Adding seminal extender during ejaculation had a significant beneficial effect at 0 and 48 h on the percentage of motile spermatozoa but not average path velocity (25% seminal plasma). There were significant differences between stallions but the stallion/ejaculate-treatment interaction was not significant at 0, 24 and 48 h. Spermatozoal motility during cooled storage of epididymal and ejaculated spermatozoa was significantly better maintained in samples containing 25% versus 0% seminal plasma. Spermatozoal motility during cooled storage was affected after spermatozoa had been exposed to seminal plasma for only 10 min after ejaculation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1998

[The effect of frequent ejaculation on semen's parameters in men with inadequate fertility].

The influence of frequent ejaculation on sperm quality in 96 men with oligozoospermia, asthenozoospermia or oligoastenozoospermia was investigated. Ejaculates were produced by each patient in short period of time (4-6 hours). In oligozoospermic group (n = 31) semen characteristics were similar between two ejaculates. In asthenozoospermic group (n = 27) the motility and the total motile sperm count increased significantly in the second ejaculate (32.1% 5.6 vs. 48.0% +/- 7.1 and 36.7 mln +/- 5.6 vs. 47.8 mln +/- 7.6 respectively). Similarly in oligoasthenozoospermic group (n = 38) the motility and the total motile sperm count increased significantly in the second ejaculate (28.1% +/- 5.3 vs. 44.2% +/- 6.2 and 7.1 mln +/- 1.2 vs. 11.3 mln +/- 2.7 respectively). In three groups, pooling two ejaculates increased significantly the total motile sperm count by 58.1%-136.6% comparing to first ejaculate. Pooling two sequential ejaculates from subfertile men is a simple method to increase the quality of sperm for assisted reproduction techniques.

Ejaculation↗
PubMed1994

Post-thaw motility and longevity of motility of imipramine-induced ejaculates of pony stallions.

Imipramine-induced ex copula ejaculates (11) and fractionated in copula ejaculates were collected from each of 5 pony stallions for freezing in 5-ml straws (6), using a modified Kenney glucose skim-milk extender (2). Initial post-thaw total and progressive motilities and daily post-thaw total and progressive motilities, as well as the number of days to reach 0 progressively motile spermatozoa, were also similar for the 2 methods of collection. The percentage of morphologically normal spermatozoa both before freezing and after thawing were also similar for in copula and ex copula ejaculates. Consistent with previous work (11), imipramine-induced ejaculates were of extremely high sperm concentration and low volume compared with those of in copula ejaculates. In this study, imipramine-induced ejaculates were of significantly higher concentration of sperm and lower volume than fractionated (first 2-3 jets) in copula ejaculates. These results suggest that imipramine-induced ejaculates may be suitable for cryopreservation. Breeding trials are necessary to evaluate actual fertility of semen.

Journal Article↗
PubMed1997

Effect of ejaculation frequency and season on donkey jack semen.

Semen characteristics of first and second successive ejaculates from 6 jacks were evaluated weekly for 12 mo. The semen was collected at 4-h intervals, using an artificial vagina with a female in either natural or induced estrus. The statistical analysis was done by factorial delineation 2 x 2 in randomized blocks. Due to some ejaculation failures, the data had to be divided into 2 Groups (A and B) for statistical analysis: Group A - ejaculates preceded by 2 ejaculates in the previous week and Group B - ejaculates preceded by only 1 ejaculate in the previous week. If no statistical difference was observed between the groups in a given parameter, the data was grouped together. Semen characteristics for the first and second ejaculates, respectively, showed the following mean +/- SEM: gel-free semen volume 29.2 +/- 2.2 and 31.7 +/- 2.2 ml; progressive motility 71.0 +/- 1.6 and 72.9 +/- 1.6%; sperm vigor 3.8 +/- 0.1 and 4.1 +/- 0.1; live spermatozoa for Group A 82.6 +/- 2.1 and 82.3 +/- 2.1%, and for Group B 84.6 +/- 1.4 and 86.6 +/- 1.4%; total number of spermatozoa for Group A 10.6 +/- 0.8 x 10(9) and 5.8 +/- 0.8 x 10(9), and for Group B 13.3 +/- 1.2 x 10(9) and 9.6 +/- 1.2 x 10(9); head abnormalities for Group A 1.2 +/- 0.3 and 1.4 +/- 0.3%, and for Group B 1.6 +/- 0.3 and 1.9 +/- 0.3%; mid piece abnormalities 7.7 +/- 0.7 and 6.1 +/- 0.7%; tail abnormalities 7.3 +/- 0.7 and 6.8 +/- 0.7%; pH 7.6 +/- 0.0 and 7.6 +/- 0.0. Significant differences (P < 0.05) were observed between the animals for all sperm characteristics except for sperm vigor. The means for the first and second ejaculates were significantly different (P < 0.05) for the total number of spermatozoa in all the animals, while the percentage of mid piece abnormalities was significantly different in only 1 jack. Seasonal effects on sperm parameters were observed only for semen pH.

Journal Article↗
PubMed2003

Towards evidence-based drug treatment research on premature ejaculation: a critical evaluation of methodology.

In the last decade, an increasing number of drug studies on premature ejaculation have been published. The methodology used in these studies differed widely. In this review, it is therefore questioned as to how far the differences in methodology could have influenced clinical outcomes. The aim of the present review was to compare the different methodologies that were used in drug studies on premature ejaculation. The majority of these studies were conducted between 1973 and 2003 and were strikingly different in study design and in the quantification of clinical outcomes. It appeared that in some of these studies, placebo and active drug effects were neglected due to an erroneous methodology. The few studies that were using stopwatch assessment at each intercourse at baseline and during treatment and in which the intravaginal ejaculation latency time (IELT) was included appeared to be comparable in their results. The use of a well-defined definition of premature ejaculation, for example, an IELT of less than 1 min revealed reproducible results. Finally, the retrospective use of a questionnaire or a subjective report on ejaculation time induced higher effects with regard to placebo effects and an underestimation of active drug effects. In conclusion, for drug treatment research of premature ejaculation it is recommended to use a randomized double-blind prospective design, the use of the IELT, the use of a stopwatch at each coitus both during a baseline period and during drug treatment and a definition of premature ejaculation as an ejaculation that occurs within 1 min after vaginal penetration.

Evidence-Based Medicine↗
PubMed1996

Abnormal prostatic cells in ejaculates from men with prostatic cancer--a preliminary report.

OBJECTIVE: To relate findings from a novel approach, ejaculate cytology, to the established reference, histopathology from transrectal ultrasonography (TRUS)-guided prostatic biopsies, in patients at risk of having prostatic cancer on the basis of an abnormal digital rectal examination (DRE) and/or an elevated serum prostate specific antigen (PSA). PATIENTS SUBJECTS AND METHODS: Thirty-seven men suspected of having prostatic carcinoma provided ejaculate specimens which were collected in Hanks solution. The specimens were centrifuged to form a pellet from which smears were made for cytological examination. Immunohistochemical staining for PSA and prostatic acid phosphatase (PAP) were performed on embedded blocks of these cells. TRUS-guided sextant biopsies were performed for histological specimens using standard clinical procedures. A control group of 32 men < 30 years of age, with no family history of prostatic cancer, also produced specimens of ejaculate which were processed similarly. RESULTS: Frankly malignant and atypical prostatic cells were identified in ejaculate specimens from 14 of the 37 patients. Of 12 patients with TRUS biopsies positive for malignancy, nine (75%) had abnormal cells in their ejaculates. Furthermore, five of 25 patients with negative biopsies for adenocarcinoma also had abnormal ejaculate cytology; two of these five patients had high-grade prostatic intra-epithelial neoplasia (PIN). In the control group, no PSA- or PAP-positive prostatic epithelial cells were identified. Normal prostatic cells were not seen in any of the ejaculate specimens examined. CONCLUSIONS: These results indicate that ejaculate cytology, which is a non-invasive and easily repeated investigation, may prove to be a useful approach in the early detection of cancer of the prostate. However, its value in this role, together with the clinical significance of cytological findings, needs to be established, especially in relation to PSA and TRUS biopsy.

Acid Phosphatase↗
PubMed2000

Comparison of telomerase activity and GSTP1 promoter methylation in ejaculate as potential screening tests for prostate cancer.

New diagnostic tools are needed for the early detection of prostatic cancer. The molecular detection of prostate cancer cells in ejaculates was evaluated using complementary PCR-based methods. LNCaP cells, a cell line derived from prostatic carcinoma, were spiked into normal seminal ejaculates and the prostatic epithelial component of the specimens was isolated by immunomagnetic bead sorting, using a monoclonal antibody to prostate-specific membrane antigen (PSMA). Ejaculates from nine patients with a recent diagnosis of prostate cancer were processed in a similar fashion, using LNCaP-spiked aliquots as an internal positive control. Telomerase expression was evaluated by the telomeric repeat amplification protocol (TRAP) and glutathione S-transferase gene promoter (GSTP1) hypermethylation was evaluated by methylation-sensitive restriction endonuclease digestion and PCR amplification. Telomerase activity was detected in LNCaP cells recovered from normal seminal ejaculates but was not found in all nine samples from patients with prostate cancer. The sensitivity of GSTP1 analysis was similar to telomerase analysis for the detection of LNCaP cells from normal ejaculate samples but was positive in ejaculates from four out of nine patients with prostate cancer. GSTP1 DNA methylation status is more sensitive than telomerase analysis for the detection of malignant cells in seminal ejaculates from patients with prostate cancer.

DNA Methylation↗
PubMed2005

Cognitive and partner-related factors in rapid ejaculation: differences between dysfunctional and functional men.

Despite the high prevalence of rapid ejaculation in community samples, there is still a paucity of data on cognitive and other relevant aspects of the subjective experience of premature ejaculation (PE) patients and their functional counterparts. Therefore, the main aim of this study was to expand our understanding of the complex nature of rapid ejaculation disorders by providing a detailed characterization of ejaculatory patterns, behavioral aspects, cognitive, and partner-related factors in a sample of unselected PE patients compared to a group of functional men. To explore the areas that might differentiate PE men from their sexually functional counterparts, a multidimensional self-administered questionnaire, the PEQuest, was created. This 36-item instrument addresses a number of domains relevant to ejaculatory function and dysfunction such as ejaculatory latencies and ejaculatory control, cognitions and feelings during sexual intercourse, factors interfering with ejaculatory control, techniques to delay ejaculation, and partnership factors. A total of 45 PE patients (mean age: 41.8 years) and 72 non-patients (mean age: 37.1 years) were included. The results show significant group differences in the majority of PEQuest domains. In the functional group, an average intravaginal latency time of 12.8 min (median: 10 min) was reported compared to 3.7 min (median: 2 min) in the patient group with 87% of PE patients ejaculating within 2 min and 100% within 5 min after penetration. In their subjective experience in sexual situations, PE patients were totally preoccupied with thoughts about controlling their orgasm, with the anxious anticipation of a possible failure, and thoughts about keeping their erection while the inner experience of functional men is focused on sexual arousal and sexual satisfaction. The factors that maximally impede the control of ejaculation are similar for both groups, but functional men normally succeed in adapting their sexual behavior to these factors whereas PE men fail in their efforts. Regarding partner-related factors, PE patients felt less secure and experienced with respect to female sexuality than their functional counterparts, and more often reported a discrepancy between their own limited experience and the more extensive sexual experience of their partner. In conclusion, a number of salient differences in ejaculatory behavior, cognitive-affective patterns, and partner-related factors between PE patients and functional men could be delineated in this study, indicating that chronic rapid ejaculation is a serious disorder with a profound impact on the man's life and his partnership.

Adult↗
PubMed2005

Animal models of premature and retarded ejaculation.

Most of our current understanding of the neurobiology of sexual behavior and ejaculatory function has been derived from animal studies using rats with normal sexual behaviour. However, none of these proposed models adequately represents human ejaculatory disorders. Based on the "ejaculation distribution theory", which postulates that the intravaginal ejaculation latency time in men is represented by a biological continuum, we have developed an animal model for the research of premature and delayed ejaculation. In this model, a large number of male Wistar rats are investigated during 4-6 weekly sexual behavioural tests. Based on the number of ejaculations during 30 min tests, rapid and sluggish ejaculating rats are distinguished, each representing approximately 10% at both ends of a Gaussian distribution. Together with other parameters, such as ejaculation latency time, these rats at either side of the spectrum resemble men with premature and delayed ejaculation, respectively. Comparable to the human situation, in a normal population of rats, endophenotypes exist with regard to basal sexual (ejaculatory) performance.

Animals↗
PubMed2005

Terazosin in the treatment of premature ejaculation: a short-term follow-up.

AIM: The aim of the present study was to evaluate the efficacy of terazosine in patients with premature ejaculation and lower urinary tract symptoms (LUTS), after excluding other sexual disorders and chronic prostatitis. METHODS: A total of 90 patients with premature ejaculation and LUTS were enrolled to the study after excluding sexual disorders, prostatitis and benign prostatic hyperplasia. The patients were divided into two groups. Sixty patients in group 1 were treated with terazosine 5 mg daily for a month. Patients were followed monthly and questioned for their ejaculation problem. The results were classified as cure, improvement and ineffective. If patients showed improvement and ineffectiveness, the treatment was continued with 10 mg daily for the following month. Group 2 was included 30 patients, and placebo was applied for a month. At the end of this period, in patients who did not show any improvement, terazosine 10 mg was started. RESULTS: In the treatment group, at the 1st month follow-up, 21 patients (35%) were cured, 20 (33.3%) showed improvement. In 19 (31.7%) patients, the treatment was ineffective. In group 2, 9 (30%) patients showed improvement and the rest had no-changes after one-month follow up. There was statistically significant difference between two groups (Pearson chi2 test = 0.000). Later, terazosine 10 mg was given to the patients in group 2 and to the patients who showed improvement or unsuccessful result with terazosine 5 mg. With terazosine 10 mg, 10 (14.5%) patients were cured, 29 (42.2%) patients were improved. Finally, terazosine treatment in patients with premature ejaculation was found to be effective in 60 patients (66.7%). CONCLUSION: Alpha blockers seem to be physiological medical agents in the treatment of premature ejaculation since ejaculation is under sympathetic control. Moreover, these agents are effective in lower urinary tract and they should be used in patients with premature ejaculation and lower urinary tract symptoms.

Adrenergic alpha-Antagonists↗
PubMed1994

Ejaculation induced changes in escape latency in the hot plate test: pharmacological analysis of anxiolytic versus analgesic effect.

The possible changes in nociception at various stages of male sexual behaviour were explored in the hot plate test. Although other authors have reported an antinociceptive effect of mating, we failed to find this effect on the hot plate test after several sexual behaviour events. To further explore the possible antinociceptive action of copulation we administered a suboptimal analgesic dose of morphine (0.3 mg/kg i.p.). No change in nociception were observed in animals treated with a subthreshold dose of morphine and tested in the nociception test after ejaculation were observed. Since previous reports have refered that ejaculation produces hypoalgesia when measured in the hot plate test, we attempted to replicate these findings. We found that one ejaculation produces an increase in the latency to escape in male rats previously habituated to the hot plate test. These results suggest a hypoalgesic effect. However, such changes could also be interpreted as alterations in the animals' emotionality. Thus, a group of habituated animals was tested on the switched off plate. An important increase in the escape latency behaviour after ejaculation was observed, while no differences between control animals, without sexual behaviour display, tested on switched on and switched off plate were observed. The participation of the benzodiazepine and opiod systems in the ejaculation effect on the switched off plate was explored. A similar increase in escape latency to that induced by ejaculation was caused by diazepam (1.0 and 2.0 mg/kg). The increase in escape latency induced by ejaculation was prevented by the benzodiazepine antagonist, flumazenil (20.0 mg/kg).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2005

Ejaculation induces long-lasting behavioural changes in male rats in the forced swimming test: evidence for an increased sensitivity to the antidepressant desipramine.

Copulation to exhaustion induces a sexual inhibitory state featured by a decreased motivation. Since diminished motivation is a key symptom of depression, we analysed if sexually exhausted animals showed increased levels of depressive-like behaviour in the forced swimming test (FST). Besides, sexual activity has been reported to have reinforcing properties. Thus, we analysed whether different levels of sexual activity modified the development of the behavioural despair in the FST. Finally, the effect of a sub-threshold dose of desipramine (DMI, 2.5mg/kg) was evaluated in animals with different sexual conditions. Male adult rats were divided into: (a) naive rats and (b) animals executing one intromission (1-INTR) or (c) one ejaculation (1-EJ) and (d) sexually satiated rats, classified as sexually responsive (R) and non-responsive (NR). No differences were found in immobility behaviour between sexually exhausted and naive rats. In the pre-test sessions of the FST males attaining ejaculation (1-EJ, R and NR) had lower levels of immobility or showed a tendency towards such a diminution, while animals with sexual activity not involving ejaculation did not. Data suggest a "protective" effect of ejaculation against the development of depressive-like behaviour. Finally, the sub-effective dose of DMI produced an antidepressant-like action in all animals that ejaculated. In conclusion, sexual experience involving ejaculation modifies the behavioural expression of rats in the FST and their sensitivity to antidepressant drugs like DMI. Both responses reflect brain plastic changes induced by ejaculation.

Analysis of Variance↗
PubMed2005

Physiology of ejaculation: emphasis on serotonergic control.

Ejaculation is constituted by two distinct phases, emission and expulsion. Orgasm, a feature perhaps unique in humans, is a cerebral process that occurs, in normal conditions, concomitantly to expulsion of semen. Normal antegrade ejaculation is a highly coordinated physiological process with emission and expulsion phases being under the control of autonomic and somatic nervous systems respectively. The central command of ejaculation is located at the thoracolumbar and lumbosacral levels of the spinal cord and is activated by stimuli from genital, mainly penile, origin although cerebral descending pathways exert both inhibitory and excitatory regulatory roles. Cerebral structures specifically activated during ejaculation form a tightly interconnected network comprising hypothalamic, diencephalic and pontine areas. A rational neurobiological approach has led to identify several neurotransmitters contributing to the ejaculatory process. Amongst them, serotonin (5-HT) has received strong experimental evidences indicating its inhibitory role in the central control of ejaculation. In particular, 5-HT1A cerebral autoreceptors but also spinal 5-HT1B and, in a lesser extent, 5-HT2C receptors have been shown to mediate the effects of 5-HT on ejaculation. Pharmacological strategies, especially those targeting serotonergic system, for the treatment of ejaculatory disorders in human will undoubtedly benefit from the application of basic and clinical research findings. In this perspective, the use of selective serotonin reuptake inhibitors (SSRIs) which basically increase the amount of central 5-HT and delay ejaculation in humans seems promising.

Central Nervous System↗
PubMed2006

Serotonin and premature ejaculation: from physiology to patient management.

INTRODUCTION: Premature ejaculation (PE), whose pathophysiology is still not clearly identified, is the most common male sexual dysfunction, yet it remains underdiagnosed and undertreated. The aims of this paper are to provide a scientific and pharmacologic rationale, and to discuss to what extent selective serotonin reuptake inhibitors (SSRIs) can help patients with PE. MATERIALS AND METHODS: A comprehensive evaluation of available published data included analysis of published full-length papers that were identified with Medline and Cancerlit from January 1981 to January 2006. Official proceedings of internationally known scientific societies held in the same time period were also assessed. RESULTS: The central ejaculatory neural circuit comprises spinal and cerebral areas that form a highly interconnected network. The sympathetic, parasympathetic, and somatic spinal centers, under the influence of sensory genital and cerebral stimuli integrated and processed at the spinal cord level, act in synergy to command physiologic events occurring during ejaculation. Experimental evidence indicates that serotonin (5-HT), throughout brain descending pathways, exerts an inhibitory role on ejaculation. To date, three 5-HT receptor subtypes (5-HT1A, 5-HT1B, and 5-HT2C) have been postulated to mediate 5-HT's modulating activity on ejaculation. Pharmacologic manipulation of the serotonergic system has been performed in rats, with the antidepressant selective serotonin reuptake inhibitors (SSRIs) exhibiting the greatest efficacy in delaying ejaculation. The mechanism of action by which SSRIs modulate central 5-HT tone has been studied in depth, but gaps in this knowledge prevent an explanation of the efficacy of acute treatment in delaying ejaculation. Emerging clinical evidence indicates chronic and on-demand dosing of SSRIs has a beneficial effect for the treatment of men with PE, at least for paroxetine. On-demand dapoxetine, and SSRI with a short half-life, recently has been shown to significantly increase intravaginal latency time and PE patient-related outcomes in phase 3 clinical trials. CONCLUSIONS: Nowadays there is no doubt that PE can be treated effectively by SSRIs. Nevertheless their mechanism of action is not yet well understood and deserves more research. In particular it is not understood why all the SSRIs are not equal in terms of their ability to delay ejaculation. Therefore, there is a need for more research to better characterize the mechanism of action of SSRIs as well their clinical benefit in patients affected by PE.

Animals↗
PubMed2006

Utrastructural analysis of asthenozoospermic ejaculates in the era of assisted procreation.

OBJECTIVE: To define by transmission electron microscopy (TEM) analysis, the prevalence of sperm tail defects of genetic origin among men suffering for a reduced or absent sperm motility. DESIGN: A retrospective study. SETTING: Andrology Clinic, University of L'Aquila, Italy. PATIENT(S): The 120 ejaculates of infertile men with a forward motility (FM) < or =20% were compared to 200 ejaculates with a FM >20%. All ejaculates had a sperm vitality >50%. INTERVENTION(S): Some 25-50 tails were analyzed by TEM in each ejaculate. MAIN OUTCOME MEASURE(S): Receiver operating characteristics (ROC) analysis was applied by plotting the FM of cases with or without genetic tail defects detected by TEM. RESULT(S): The area under the ROC curve was 0.96 (95% confidence interval 0.92-0.98). The positive predictive accuracy for genetic tail defects in ejaculates with 0% FM was 46%. Three of 17 cases with genetic tail defects were classified as false negative when TEM analysis was restricted to ejaculates with 0% FM. A FM < or =7%, allowed the identification of all cases with genetic tail defects. CONCLUSION(S): The TEM analysis identifies sperm tail defects of genetic origin and should be restricted to ejaculates with severe asthenozoospermia (< or =7% motile sperm) and sperm vitality >50%.

Ejaculation↗