Effects of ejaculation by penile vibratory stimulation on bladder capacity in men with spinal cord lesions

PURPOSE: We examined the effects of ejaculation by penile vibratory stimulation on bladder capacity in men with spinal cord lesions. MATERIAL AND METHODS: Included in our study were 14 men with spinal cord lesions from C4 to T7 with detrusor hyperreflexia. Cystometry was performed before and immediately after ejaculation by penile vibratory stimulation to establish baseline conditions and repeated after 1 month of ejaculation by penile vibratory stimulation every third day. The third cystometry study was done after 1 month of ejaculation by penile vibratory stimulation every third day at home to determine any long-term effects of treatment. This third cystometry was performed 72 hours after the last ejaculation to exclude any acute effects of ejaculation by penile vibratory stimulation on detrusor hyperreflexia. In addition, 1 to 3 days later ejaculation was induced by penile vibratory stimulation and immediately followed by cystometry to examine whether it was possible to achieve an acute effect as well as a potential long-term effect. RESULTS: Baseline urodynamic investigations revealed bladder hyperreflexia and external sphincter dyssynergia in all individuals. There was no statistically significant difference in bladder capacity at leak point before and immediately after ejaculation by penile vibratory stimulation. However, after 4 weeks of frequent penile vibratory stimulation treatment bladder capacity at leak point increased significantly from a median of 190 ml. (range 17 to 700) at baseline to 293 (range 30 to 700) (Wilcoxon signed rank test p = 0.03). Furthermore, there was a trend toward decreased intravesical pressure during the filling phase. CONCLUSIONS: Ejaculation by penile vibratory stimulation was associated with a significant increase in bladder capacity at leak point after 4 weeks of frequent treatment. This finding may have implications in the management of incontinence in men with spinal cord lesions.     

Ejaculatory disorder caused by alpha-1 adrenoceptor antagonists is not retrograde ejaculation but a loss of seminal emission

AIM: The etiology of the ejaculatory disorder induced by alpha-1 blockers is still controversial, although it has been suggested to be retrograde ejaculation. The aim of this study was to investigate the distribution of alpha-1 adrenoceptor subtype mRNA in human seminal vesicles, and to analyze the prevalence and etiology of the disorder in healthy men. METHODS: Experimental Study. Seminal vesicles from 10 surgical specimens (eight radical prostatectomy, two radical cystectomy) were dissected. Real-time PCR was conducted for quantification of mRNA expression of each alpha-1 adrenoceptor subtype. Clinical Study. Ejaculatory disorder was investigated using 17 healthy male volunteers. Tamsulosin (0.2 mg and 0.4 mg) and naftopidil (50 mg and 100 mg) were administered in a crossover manner for 3 days. The ejaculatory volume, sperm count in midstream urine after ejaculation, and fructose concentration in seminal plasma were investigated. RESULTS: Real-time PCR revealed that alpha-1a mRNA was significantly predominant in seminal vesicles (P < 0.001; 1a, 75.0%; 1b, 11.7%; 1d, 13.3%). Ejaculatory volume (baseline 2.72 +/- 0.28 mL) significantly decreased in the tamsulosin group (0.2 mg, 1.75 +/- 0.31 mL; 0.4 mg, 1.51 +/- 0.39 mL; P < 0.05), but not in the naftopidil group (50 mg, 2.70 +/- 0.24 mL; 100 mg, 2.48 +/- 0.26 mL; P = NS). There was no sperm in midstream urine after any ejaculation. CONCLUSIONS: The current study demonstrates that alpha-1a mRNA is predominant among the adrenoceptor subtypes in human seminal vesicles. Decreased capacity of contraction of the seminal vesicles is proposed as the cause of the ejaculatory disorder induced by alpha-1 blockers.     

Transurethral resection of the ejaculatory ducts for treating ejaculatory symptoms

OBJECTIVES: To report our experience with transurethral resection of the ejaculatory ducts (TURED) in infertile men with symptomatic ejaculatory duct obstruction (EDO). PATIENTS AND METHODS: Before surgery, all patients complained of a decrease in the volume of their ejaculate, 14 of 15 had a non-projectile ejaculation, nine had a genitourinary infection necessitating antibiotic treatment, and five had pain with orgasm. The mean ejaculate volume and total motile sperm count was 1.1 mL and 8.1 million sperm per ejaculate. After surgery, at a mean follow-up of 2 months, 10 men reported having projectile ejaculation, and eight reported a marked improvement in their sensation of orgasm. Overall, 14 men reported a subjective improvement in their ejaculation. The average postoperative ejaculate volume was 2.3 mL and the total motile sperm count was 38.1 million per ejaculate. CONCLUSIONS: Men with symptomatic EDO who underwent TURED showed improvements in their ejaculation, sensation of orgasm, semen analysis values and fertility.     

The effects of three phosphodiesterase type 5 inhibitors on ejaculation latency time in lifelong premature ejaculators: a double-blind laboratory setting study

Study Type – Therapy (RCT)
Level of Evidence 1b What’s known on the subject? and What does the study add? Several authors have reported their experience with PDE5 inhibitors alone or in combination with selective serotonin re‐uptake inhibitors for treating premature ejaculation. However, to our knowledge, this is the first laboratory design study to evaluate the effects of three PDE5 inhibitors throughout the ejaculation process in men with lifelong premature ejaculation. In this laboratory setting study PDE5 inhibitors seem to prolong ELT but the difference from placebo is significant only in vardenafil. The quality of penile rigidity is better with PDE5 inhibitors in the post‐ejaculatory period but the difference is significant only in sildenafil and vardenafil.

OBJECTIVE

? To evaluate the effects of three phosphodiesterase type 5 (PDE5) inhibitors on the ejaculation process in men with lifelong premature ejaculation using a double‐blind laboratory setting.

PATIENTS AND METHODS

? Eighty men with lifelong premature ejaculation, 20 in each group, received placebo, vardenafil (10 mg), sildenafil (50 mg) or tadalafil (20 mg) in a double‐blind study design. Placebo or PDE5 inhibitor was ingested after at least 2 h fasting and non‐smoking. The subjects were placed in a silent room immediately and real‐time penile rigidity and tumescence was monitored. ? Subjects read some magazines or newspapers without any sexually stimulating material for 1.5 h. At the end of this period audiovisual sexual stimulation began with a video film and after the 8th minute the subject began vibratory stimulation to the frenular area. ? At the beginning of ejaculation the patient stopped stimulation. When the patient began and stopped stimulation, the light near the observer turned on and off and the observer calculated the ejaculation period with a chronometer. The elapsed time was the ejaculation latency time (ELT) in seconds. ? There was no interaction between subjects and observer during the test. The ELT, and the qualities of base and tip rigidities during ELT and after ejaculation were calculated.

RESULTS

? Median age of patients was 29 (range 22–39) years and median duration of premature ejaculation was 60 (range 7–180) months and there was no significant difference between groups. Median duration of vibratory stimulation (ELT) of subjects who received placebo was 48.5 s: 53.5 s for sildenafil, 70.0 s for tadalafil and 82.5 s for vardenafil. Compared with the placebo group, ELT was significantly longer only in subjects receiving vardenafil (P = 0.019). ? In the post‐ejaculatory refractory period, times to last recorded base rigidities were significantly longer than placebo in vardenafil and sildenafil groups with better erection quality (P < 0.01 for each).

CONCLUSIONS

? The PDE5 inhibitors seem to prolong ELT and the quality of penile rigidity is better with PDE5 inhibitors in post‐ejaculatory period. ? These findings suggest that PDE5 inhibitors might have some beneficial effects in men with lifelong premature ejaculation.     

alpha-Adrenergic agents modulate the activity of the spinal pattern generator for ejaculation

Spinal cord transection at a thoracic level activates fictive ejaculation (FE) in the male rat. It has earlier been demonstrated that fictive motor patterns may be activated by pharmacological means and that the noradrenergic system seems to be particularly efficient in triggering locomotor fictive patterns in spinal animals. In the present study, the hypothesis was tested that the spinal noradrenergic system participates in the activation of the spinal generator for ejaculation (SGE). To this aim, the effect of the adrenergic agents, methoxamine, prazosin, clonidine, and yohimbine, upon FE was evaluated in spinal male rats using electromyographic techniques. The results obtained show that ejaculatory rhythmic patterns, accompanied by the expulsion of urethral contents and phasic penile movements, can be elicited by the intravenous (i.v.) injection of methoxamine or yohimbine. These drug-induced motor sequences appear superimposed to the intrinsic ejaculatory spinal rhythm. By contrast, i.v. injection of prazosin or clonidine blocked the expression of the spontaneous ejaculatory rhythmic pattern without inducing any other genital response. These data suggest that an increased noradrenergic tone, either by blockade of presynaptic alpha2-adrenoceptors or by stimulation of postsynaptic alpha1-adrenoceptors, results in the activation of the SGE. Present findings provide the evidence that the SGE might be importantly influenced by the noradrenergic system, which exerts a facilitatory control on the expression of the genital motor pattern of ejaculation.     

Benign prostatic hyperplasia (BPH) and prostatitis: prevalence of painful ejaculation in men with clinical BPH

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.     

Ejaculatory dysfunction in men with diabetes mellitus

Diabetes mellitus(DM) is a metabolic disorder that is characterized by elevated blood glucose levels due to absolute or relative insulin deficiency, in the background of β-cell dysfunction, insulin resistance, or both. Such chronic hyperglycemia is linked to long-term damage to blood vessels, nerves, and various organs. Currently, the worldwide burden of DM and its complications is in increase. Male sexual dysfunction is one of the famous complications of DM, including abnormal orgasmic/ejaculatory functions, desire/libido, and erection. Ejaculatory dysfunction encompasses several disorders related to DM and its complications, such as premature ejaculation, anejaculation(AE), delayed ejaculation, retrograde ejaculation(RE), ejaculatory pain, anesthetic ejaculation, decreased ejaculate volume, and decreased force of ejaculation. The problems linked to ejaculatory dysfunction may extend beyond the poor quality of life in diabetics as both AE and RE are alleged to alter the fertility potential of these patients. However, although both diabetes patients and their physicians are increasingly aware of diabetic ejaculatory dysfunction, this awareness still lags behind that of other diabetes complications. Therefore, all these disorders should be looked for thoroughly during the clinical evaluation of diabetic men. Besides, introducing the suitable option and/or maneuvers to treat these disorders should be tailored according to each case. This review aimed to explore the most important findings regarding ejaculatory dysfunction in diabetes from pre-clinical and clinical perspectives.     

Ejaculatory dysfunction caused by the new α1‐blocker silodosin: A preliminary study to analyze human ejaculation using color Doppler ultrasonography

Objectives: In order to clinically investigate the mechanism of ejaculatory dysfunction attributable to the α₁‐blocker silodosin, a real‐time observation of ejaculation by healthy males was performed. Methods: Following intake of silodosin, a newly developed selective α₁‐blocker for benign prostatic hypertrophy, ejaculation was dynamically observed using color Doppler ultrasound in three healthy males. Normal ejaculation was also investigated in the same manner. Results: With silodosin intake, no antegrade ejaculation was observed in cases 1 or 2. In case 1, seminal fluid slowly but continuously flowed out from the seminal vesicles into the bladder. In case 2, only a small amount of seminal fluid flowed into the bladder during the ejaculatory sensation. In case 3, ejection of a small amount of semen from the external urethral orifice was observed and inflow of a small amount of seminal fluid into the bladder was also captured. Without silodosin intake, all three subjects exhibited antegrade ejaculation. Conclusions: The mechanism of ejaculatory dysfunction is intricately related to retrograde ejaculation (retrograde inflow of seminal fluid), insufficient contraction of the seminal vesicles, and insufficient rhythmic contraction of the muscles of the pelvic floor.     

Male sexual dysfunction and infertility associated with neurological disorders

Normal sexual and reproductive functions depend largely on neurological mechanisms. Neurological defects in men can cause infertility through erectile dysfunction, ejaculatory dysfunction and semen abnormalities. Among the major conditions contributing to these symptoms are pelvic and retroperitoneal surgery, diabetes, congenital spinal abnormalities, multiple sclerosis and spinal cord injury. Erectile dysfunction can be managed by an increasingly invasive range of treatments including medications, injection therapy and the surgical insertion of a penile implant. Retrograde ejaculation is managed by medications to reverse the condition in mild cases and in bladder harvest of semen after ejaculation in more severe cases. Anejaculation might also be managed by medication in mild cases while assisted ejaculatory techniques including penile vibratory stimulation and electroejaculation are used in more severe cases. If these measures fail, surgical sperm retrieval can be attempted. Ejaculation with penile vibratory stimulation can be done by some spinal cord injured men and their partners at home, followed by in-home insemination if circumstances and sperm quality are adequate. The other options always require assisted reproductive techniques including intrauterine insemination or in vitro fertilization with or without intracytoplasmic sperm injection. The method of choice depends largely on the number of motile sperm in the ejaculate.     

射精时泄精和膀胱颈关闭的控制机理

通过对犬胸腰段内脏神经的电刺激来验证射精时交感神经信号的传导径路。该信号在射精时，使精液从射精管道泄出并使膀胱颈关闭。在大的胸腰段内脏神经中有两组神经纤维，一组从胸段和腰１的交感神经干发出，下行到主动脉前壁上的肠系膜尾丛（相当于人类的肠系膜下神经丛和腹下丛的上部）；另一组从腰段（腰１～腰５）的交感神经干发出，延伸到主动脉前壁，但不覆盖精索动脉，称为腰部内脏神经。用电刺激第１组神经，既不引起泄精，也不引起膀胱颈关闭；而刺激第２组神经（腰部内脏神经）的每一分支，都可引起泄精和膀胱颈关闭，当腹下神经被切断后，上述两种现象就不再发生。经过一段时间后，由于腰骶交感神经干和精索神经的代偿作用可恢复泄精，但膀胱颈关闭得不到代偿。因此，切断腹下神经可导致大的逆行射精。     

The etiology and management of premature ejaculation

Premature ejaculation (PE) is a common male sexual disorder. Normative data suggest that men with an intravaginal ejaculatory latency time of less than 1 min have 'definite' premature ejaculation, while men with intravaginal ejaculatory latency times of between 1 and 1.5 min have 'probable' premature ejaculation. Although there is insufficient empirical evidence to identify the etiology of PE, there is correlational evidence to suggest that men with PE have high levels of sexual anxiety and altered sensitivity of central 5-hydroxytryptamine receptors. Pharmacological modulation of the ejaculatory threshold using daily or on-demand selective serotonin reuptake inhibitors offers patients a high likelihood of achieving improved ejaculatory control within a few days of initiating treatment, leads to improvements in sexual desire and other sexual domains, and is well tolerated.     

Penile vibratory stimulation and electroejaculation in the treatment of ejaculatory dysfunction

The purpose of this review is to present the current understanding of penile vibratory stimulation (PVS) and electroejaculation (EEJ) procedures and its clinical use in men with ejaculatory dysfunction. Unfortunately, the record of treating such individuals has been quite poor, but within recent years development and refinement of PVS and EEJ in men with spinal cord injury (SCI) has significantly enhanced the prospects for treatment of ejaculatory dysfunction. The majority of spinal cord injured men are not able to produce antegrade ejaculation by masturbation or sexual stimulation. However, approximately 80% of all spinal cord injured men with an intact ejaculatory reflex arc (above T10) can obtain antegrade ejaculation with PVS. Electroejaculation may be successful in obtaining ejaculate from men with all types of SCI, including men who do not have major components of the ejaculatory reflex arc. Because vibratory stimulation is very simple in use, non-invasive, it does not require anaesthesia and is preferred by the patients when compared with EEJ, PVS is recommended to be the first choice of treatment in spinal cord injured men. Furthermore, EEJ has been successfully used to induce ejaculation in men with multiple sclerosis and diabetic neuropathy. Any other conditions which affect the ejaculatory mechanism of the central and/or peripheral nervous system including surgical nerve injury may be treated successfully with EEJ. Finally, for sperm retrieval and sperm cryopreservation before intensive anticancer therapy in pubertal boys, PVS and EEJ have been successfully performed in patients who failed to obtain ejaculation by masturbation. Nearly all data concerning semen characteristics in men with ejaculatory dysfuntion originate from spinal cord injured men. Semen analyses demonstrate low sperm motility rates in the majority of spinal cord injured men. The data give evidence of a decline in spermatogenesis and motility of ejaculated spermatozoa shortly after (few weeks) an acute SCI. Furthermore, it is suggested that some factors in the seminal plasma and/or disordered storage of spermatozoa in the seminal vesicles are mainly responsible for the impaired semen profiles in men with chronic SCI. Home insemination with semen obtained by penile vibratory and introduced intravaginally in order to achieve successful pregnancies may be an option for some spinal cord injured men and their partners. The majority of men will further enhance their fertility potential when using either penile vibratory or EEJ combined with assisted reproduction techniques such as intrauterine insemination or in-vitro fertilization with or without intracytoplasmic sperm injection.     

Alpha-2 adrenoreceptors probably do not mediate the immobility produced by inhaled anesthetics

Agonism of alpha-adrenoreceptors has a powerful anesthetic result mediated, in part, by effects on the spinal cord. Alpha-adrenoreceptor agonists (e.g., dexmedetomidine) can decrease the minimum alveolar anesthetic concentration (MAC) of inhaled anesthetics (e.g., halothane) to zero, with an apparently additive interaction between halothane and dexmedetomidine. We tested whether the capacity of the inhaled anesthetic isoflurane to produce immobility in the face of noxious stimulation resulted from agonism of alpha-adrenoreceptors. MAC (the concentration required to eliminate movement in response to a noxious stimulus in 50% of subjects) of isoflurane was determined before and after intraperitoneal administration of the alpha-adrenoreceptor antagonists yohimbine and atipamezole. The doses of yohimbine and atipamezole equaled or exceeded those that reverse the ability of agonism of alpha-adrenoreceptors to decrease MAC. Smaller doses of yohimbine or atipamezole slightly increased (by 10%) the MAC of isoflurane, an increase we interpret as the result of blockade of a small amount of tonically active alpha-adrenoreceptor activity. Doses five-fold larger did not change MAC. Doses 10-fold larger decreased MAC. We conclude that alpha-adrenoreceptors do not or minimally mediate the capacity of inhaled anesthetics to produce immobility. IMPLICATIONS: Although stimulation (agonism) of alpha-2 adrenoreceptors can decrease the inhaled anesthetic concentration required to produce immobility in the face of noxious stimulation, blockade of alpha-2 adrenoreceptors minimally affects the concentration. Thus, augmentation of the effect of alpha-2 adrenoreceptors is not an appreciable part of the mechanism whereby inhaled anesthetics produce immobility.     

Decreased prostatic secretory function in canine benign prostatic hyperplasia is not due to decreased levels of muscarinic cholinergic receptors

The ejaculatory volume and the prostatic secretory capacity (ml. ejaculate per gm. prostate wet weight) were determined for a group of dogs with normal and hyperplastic prostates. The ejaculatory volume and prostatic secretory capacity in dogs with BPH were decreased by 70 per cent and 80 per cent respectively, compared to dogs with normal prostates. Radioligand receptor binding using [3H]N-methylscopolamine, a muscarinic cholinergic antagonist, was performed on a similar group of dogs with normal and hyperplastic prostates. The mean equilibrium dissociation constant for the binding of [3H]N-methylscopolamine to homogenates obtained from normal and hyperplastic prostates was 0.21 nM. and 0.19 nM. respectively, demonstrating that the affinity of the receptor binding sites was not altered by the development of BPH. The tissue density of the muscarinic cholinergic receptors (fmol. per mg. prostate wet weight) and the cellular density of these receptors (fmol. per mg. DNA) were not significantly different in normal and hyperplastic prostates. These data indicate that the dramatic reduction in prostatic secretory capacity associated with canine BPH is not related to changes in the muscarinic cholinergic receptor binding capacity.     

Sexual function of LUTS patients before and after neodymium laser prostatectomy and transurethral resection of prostate. A prospective, randomized trial

OBJECTIVE: To assess and compare the sexual function of patients undergoing transurethral resection of the prostate (TURP) or Nd:YAG laser treatment for lower urinary tract symptoms (LUTS) caused by obstructing benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: 98 LUTS patients with urodynamically confirmed bladder outlet obstruction were recruited. Patients were randomised to TURP and laser treatment, which was further divided to contact and hybrid treatments according to prostate size. The sexual function at baseline and at 1 year postoperatively was assessed from the Danish Prostate Symptom Score Sexual Function Questionnaire (DanPSS Sex) items concerned with erectile stiffness, ejaculatory volume and pain or discomfort on ejaculation. RESULTS: The sexual function data at 1 year was available for 83 patients. At baseline, a high prevalence of erectile dysfunction (86%), ejaculatory volume change (83%) and pain or discomfort on ejaculation (26%) was observed and considered problematic by 79%, 63% and 100% of men, respectively. An increase of total impotence in the TURP group was observed (p = 0.046). TURP decreased or totally eradicated the amount of ejaculate, which was the only difference found between the study groups (p < 0.001). Both laser and TURP treatments improved pain or discomfort on ejaculation. CONCLUSIONS: The prevalence of sexual dysfunction in patients with symptomatic infravesical obstruction caused by BPH is high and perceived mostly as bothersome. TURP, Nd:YAG contact or hybrid laser treatments did not increase erectile dysfunction but improved pain or discomfort on ejaculation. The only significant difference between these treatments in respect to sexual function was a higher incidence of decreased or absent ejaculate after TURP.     

Changes in the quality of rabbit semen in 14 consecutive ejaculates obtained every 15 minutes

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.     

Alpha-2 adrenergic antagonism enhances risk of ventricular tachycardia during acute ischemia

OBJECTIVE: In this study we tested the hypothesis that alpha-2 adrenergic antagonism could facilitate induction of previously non-inducible ventricular tachycardia (VT) during acute ischemia. Previous reports suggest that VT during ischemia may be modulated by (alpha-2 adrenergic agonists. DESIGN: The left anterior descending artery was occluded after instrumentation of the ischemic risk zone with 21 multipolar plunge needles, each recording 6 bipolar electrograms. Three dimensional mapping characterized the mechanism of VT induced with extrastimuli. RESULTS: Of 16 non-inducible dogs included, eight which were given the alpha-2 adrenergic antagonist yohimbine all had inducible VT, while all eight in the control group remained non-inducible (p < 0.05). Six of the VTs were of focal Purkinje origin. The cycle length of the VTwas 119 +/- 4 ms. Mean arterial pressure (81+/- 8 to 82 +/- 8 mmHg, p = ns), ventricular effective refractory period (146 +/- 6 to 144 +/- 5 ms, p = ns) and ischemic zone size (55 +/-6% vs. 61 +/- 4%, p = 0.45) were not altered by yohimbine indicating minimal central or pre-junctional effects of the drug. CONCLUSIONS: Yohimbine facilitates induction of VT, especially those with focal Purkinje fiber origin, suggestive of an effect mediated through antagonism of post-junctional alpha-2 adrenoceptors on Purkinje fibers.     

Electromyographic study of ejaculatory mechanism

Cavernosus muscle (CM), seminal vesicle (SV) and vasal ampullary (VA) contractions at ejaculation are said to be reflex mechanisms (ejaculatory reflex), which have been scarcely dealt with in the literature. We investigated the hypothesis that contraction of the CMs, SVs and VA at ejaculation is a reflex action. The electromyographic (EMG) activity of CM, SV and VA during ejaculation was recorded in 28 healthy men. The test was repeated after separate anaesthetization of the glans penis (GP), CMs, SVs, and VA in the pre-ejaculatory period. Latent ejaculatory time (LET) was calculated. CMs showed no EMG activity until rigid erection phase was reached. SVs and VA exhibited resting EMG activity which increased gradually with different stages of erection. At ejaculation, CMs, SVs and VA showed two to four intermittent contractions. The mean LET was 1.3 ± 0.2 sec. GP anaesthetization led to the disappearance of CM, SV and VA EMG activity at ejaculation, while bland gel did not affect EMG activity. CMs, SVs and VA when anaesthetized in the pre-ejaculatory period exhibited no EMG activity at ejaculation, while saline did not affect EMG activity. Increased EMG activity of CM, SV and VA apparently denotes increase in their contractile activity. CM, SV and VA contraction on GP stimulation and ejaculation are assumed to be reflex actions and are mediated through the 'glans-cavernosovesicular reflex' (GCVR) which presumably represents the ejaculatory reflex. Changes in LET or evoked response would indicate a defect in the reflex pathway. The GCVR might act as an investigative tool in diagnosing erectile dysfunction, provided further studies are performed in this respect.     

Case report: Endoscopic laser lithotripsy of seminal-vesicle stones

A 25-year-old man presented with painful ejaculation, an ejaculate volume of 0.75, and complaints of passing "granules" in the semen. Transrectal ultrasonography showed bilateral seminal vesicle enlargement. The patient underwent transurethral resection of the ejaculatory duct. The entry point of duct was resected using pure cutting current, resulting in the passage of multiple proteinaceous-appearing stones. Approximately 10 months later, the patient reported recurrent painful ejaculation and passage of granules in his semen. At cystoscopy, the ejaculatory duct openings were intubated with a cone-tipped catheter to perform bilateral seminal vesiculograms, which showed numerous mobile filling defects and a Steinstrasse appearance at the ejaculatory ducts. A 7F semirigid ureteroscope entered the lumen without difficulty over a guidewire, and the stones were fragmented with a 270-microm holmium laser fiber. The ejaculatory ducts were balloon dilated to 18F. To our knowledge, this is the first reported case where a ureteroscope was utilized to treat seminal-vesicle stones. The seminal vesiculogram proved to be extremely valuable in the diagnosis.     

Bersama engleriana对脊髓损伤雄性大鼠体外射精潜力影响的评估

本研究旨在探讨Bersama engleriana对脊髓损伤雄性大鼠虚构射精潜力的影响及潜在作用机制。在注射和不注射多巴胺（12mg kg^-1）或催产素（0．5UI kg^-1）的两种条件下,将大鼠脊髓横向切断,用氨基甲酸乙酯麻醉,再分别静脉注射从Bersama engleriana枯叶中提取的水提物（100mg kg^-1）和醇提物（100mg kg^-1）,记录大鼠海绵体肌的肌电活动。序贯疗法结束后每5分钟机械刺激尿道。按照100mg kg^-1的剂量单独静脉注射水提物和醇提物都不能诱导虚构射精。注射植物提取物和生理盐水（200GL／min）的肌电图记录相似,都不能诱导球海绵体肌收缩。多巴胺（12mg kg^-1）和催产素（0．5UI kg^-1）能诱导快速的节律性收缩,伴有阴茎勃起,有时会有精栓排出。用植物提取物对大鼠进行前处理,多巴胺（12mg kg^-1）和催产素（0．5UI kg^-1）诱导的射精完全消失．序贯疗法结束后每5分钟机械刺激尿道总是能诱导阴茎运动和勃起。Bensama engleriana提取物对脊髓损伤雄性大鼠虚构射精活动的作用通过多巴胺和催产素通道进行调节。Bersama engleriana的这种延长射精潜伏期的作用可用于快速射精病人。