Significance of assay of nucleated RBCs in umbilical cord blood in neonates with meconium-stained amniotic fluid.

BACKGROUND: Approximately 8-15% of all infants are born with evidence of meconium-stained amniotic fluid (MSAF). MSAF is a potentially serious sign of fetal compromise and may indicate fetal hypoxia Objectives and aim of the work: The present study was designed to evaluate the relationship between meconium stained amniotic fluid and fetal nucleated red blood cell counts. As well, we aim to evaluate the relationship between the presence of meconium in amniotic fluid and Apgar scores in neonates. SUBJECTS AND METHODS: A prospectively case-controlled study was performed on 40 women with clear amniotic fluid as control and 40 women with meconium-stained amniotic fluid as the study group. At delivery, 2 ml of umbilical cord blood was collected and analyzed for nucleated red blood cell (NRBC). RESULTS: The mean NRBC counts in meconium-stained amniotic fluid was significantly higher than the control group (18.35 ± 7.7 and 9.6 ± 4.96), respectively (p < .001). There were statistically significant differences concerning 1- and 5-min Apgar scores with lower values in the MSAF group (p < .001 and .001, respectively). CONCLUSION: Our results support previous studies which indicate the presence of meconium can be associated with chronic fetal hypoxia as demonstrated by elevated fetal NRBC levels.

Rectocele repair with stapled transvaginal rectal resection.

BACKGROUND: Constipation is a clinical symptom in patients suffering from slow transit and/or obstructed defecation. Proper treatment requires the identification of all associated disorders and the quantification of symptoms. Rectocele can cause the symptoms of obstructed defecation syndrome (ODS). The aim of this study was to evaluate the clinical and functional outcomes of a novel technique of transvaginal stapled rectal resection (TVSRR) using a straight staple line, to treat rectocele. METHODS: The study included 84 females [median age 51 years (range 29-73 years)], with obstructed defecation, grades II-III rectocele, and multiple abnormalities on defecography. The magnitude and degree of ODS were quantified by the Altomare ODS scoring system. Continence status was evaluated using the Pescatori scoring system. The rectal and vaginal manometric study, the index of patient satisfaction using a visual analog score (VAS), and the validated Patient Assessment of Constipation Quality of Life (PAC-QOL) questionnaire results were recorded. All patients underwent TVSRR. RESULTS: There were no intraoperative complications. Early postoperative complications were defecatory urgency in seven patients (8.3 %), dyspareunia in two (2.4 %), and rectovaginal fistula in one (1.2 %). Five patients (6 %) had recurrence of ODS symptoms. There was no significant change in continence pre- and postoperatively. The ODS score and VAS revealed significant improvement within the first postoperative year in 94 % of patients. The PAC-QOL questionnaire mean total scores indicated an improvement in both the patient satisfaction and the QOL during the 12-month follow-up. The self-reported definitive outcome was excellent in 46 patients (54.7 %), good in 29 (34.5 %), fairly good in 20 (23.8 %), and poor in five (6.0 %). CONCLUSIONS: Vaginal repair carries no risk of fecal incontinence. Large anterior rectocele is considered the main indication for this technique. Using the linear stapler is a cost-effective, simple, and easy technique.

Combined partial fistulectomy and electro-cauterization of the intersphincteric tract as a sphincter-sparing treatment of complex anal fistula: clinical and functional outcome.

BACKGROUND: The aim of this study was to report a simple, effective and safe procedure, associated with minimal risk of incontinence and recurrence, for treating complex anal fistulas. METHODS: This was a prospective study of 53 consecutive patients with complex anal fistulas. The technique used included excision of the distal part of the fistula tract down to the external anal sphincter and electro-cauterization of the intersphincteric part of the tract with simple closure of the internal opening. Data collected included patient characteristics, fistula type determined by magnetic resonance imaging, pre- and postoperative continence status evaluated using the Wexner incontinence score (0-10), previous operations, hospital stay, healing time, recurrence rate and complications. RESULTS: The patients had a mean age of 41.37 ± 7.82 years; the most frequent fistula type was the high transsphincteric fistula; the mean follow-up period was 19 months with a success rate of 92.5 %; the mean wound healing time was 3.6 weeks; the incontinence scores were the same as before the procedure. The recurrence rate was 7.5 %. CONCLUSIONS: Partial fistulectomy combined with electrocauterization of the intersphincteric fistula tract is a simple, and effective procedure for the treatment of complex anal fistulas.

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.

An experimental study on the effect of different types of textiles on conception.

To study the effect of different types of textiles on conception. A total of 35 female dogs were divided into five equal groups: four test and one control. Each of the four test groups was dressed in one type of textile underpants made of either 100% polyester, 50/50% polyester-cotton mix, 100% cotton, or 100% wool. The pants were worn for 12 months. The dogs were followed during this period and for 6 months after removal of the pants by measuring the serum oestradiol 17beta and progesterone and by mating. Electrostatic potentials were also measured on the textile-covered skin. Eight bitches wearing polyester-containing textile showed diminished serum progesterone in the oestrus of the oestrous cycle, and did not conceive on mating or insemination. Five months after pants had been removed, serum progesterone of the eight dogs had normalised, and they conceived. Electrostatic potentials were detected on the skin of all dogs dressed in polyester-containing textile. The low serum progesterone and non-conception of the eight dogs could point to anovulation and failure of luteinisation. It is suggested that the electrostatic potentials detected on the skin create an 'electrostatic field' that inhibits the ovarian function. However, the effect proved to be reversible.

A study of the effect of straining on the cavernosus muscles: identification of 'straining-cavernosus reflex' and its clinical significance.

Bulbo/ischiocavernosus muscles (BCM, ICM) were found to contract on straining. We investigated the hypothesis that straining effects cavernosus muscles' contraction through a reflex action. The response of the BCM and ICM electromyographic (EMG) activity to increased intra-abdominal pressure (straining) as recorded by the intravesical pressure was registered in 32 healthy volunteers (age 39.2 +/- 10.3 years, 20 men, 12 women). The latency of the response was recorded. Responses were registered again in 17 subjects after individual anaesthetisation of urinary bladder, BCM, and ICM. BCM and ICM EMG activity increased progressively with increasing straining. It was not evoked after frequent successive straining. Latency decreased gradually with increase of straining intensity. Cavernosus muscles did not respond to straining after bladder and cavernosus muscles had been individually anaesthetised. Straining appears to effect cavernosus muscles' contraction through the 'straining-cavernosus reflex'. Cavernosus muscles' contraction produces compression of the penile and clitoral cavernous tissue. BCM contraction, furthermore, causes narrowing or closure of the vaginal introitus. The vagina is suggested to become a high pressure closed cavity which counteracts the increased intra-abdominal pressure and uterine tendency to prolapse. Meanwhile, the elevated intravaginal pressure presumably supports the rectovaginal septum against the concomitant high intrarectal pressure.

Identification of a vaginal pacemaker: An immunohistochemical and morphometric study.

Vaginal electric waves spread caudally in the vagina. We investigated the hypothesis that electric waves originate from a centre of interstitial cells of Cajal (ICCs) in the proximal vagina. Specimens (0.75 x 0.75 cm) were obtained from the vaginal walls of 23 cadavers (age 38.2 +/- 10.2 years). Sections were prepared for immunohistochemical investigations using the specific ICC marker, C-kit. Morphometric studies for image analysis using a Leica imaging system were performed. C-kit positive cells were detected in vaginal smooth muscle. Results from image analyser revealed that mean area percent of positive immunoreactivity for C-kit in the upper part of posterior vaginal wall was significantly higher (p < 0.0001) than of areas in other vaginal walls, and also significantly higher (p < 0.05) in circular than in longitudinal muscle layer. Studies have shown that the greatest collection of ICCs occurred in the upper part of the posterior vaginal wall. The vaginal electric waves are suggested to originate from this 'centre' and spread caudally.

Effect of cooling on the rectal tone.

OBJECTIVES: It has been claimed that recognizable organized sensory nerve endings could not be detected in the rectal wall. Hence the identification of cold receptors sensitive to cold temperature in the rectal wall has so far not been reported in the literature. We investigated the hypothesis that rectal cooling effected an increase of the rectal tone. METHODS: Twenty-eight healthy volunteers (18 men, 10 women, age 26-50 years) were studied. The rectal wall tone was assessed by the barostat system during infusion of normal saline at 30 degrees C and at 4 degrees C. The test was repeated after rectal anesthetization with lidocaine. RESULTS: The rectal tone on rectal saline infusion showed no response at a temperature of 30 degrees C, and asignificant increase (p < 0.05) at 4 degrees C. The latency measured by the switch-inflation apparatus recorded a mean of 15.3 +/- 1.2 ms. Iced saline infusion into the anesthetized rectum effected no significant change in the rectal tone. CONCLUSIONS: The current study has demonstrated that rectal infusion of iced saline produced an increase of the rectal tone. This effect is suggested to be a reflex and mediated through the 'rectal cooling reflex'. The reflex is suggested to act as an investigative tool in the diagnosis of rectal motile disorders provided further studies are performed.

Rectal cooling test in the differentiation between constipation due to rectal inertia and anismus.

BACKGROUND: The differentiation between constipation due to rectal inertia and that due to outlet obstruction from non-relaxing puborectalis muscle (PRM) is problematic and not easily achieved with one diagnostic test. Therefore, we studied the hypothesis that the rectal cooling test (RCT) can effectively be used to differentiate between those two forms of constipation. METHODS: The study enrolled 28 patients with constipation and abnormal transit study in whom radio-opaque markers accumulated in the rectum; 15 healthy volunteers acted as controls. Electromyographic activity of the external anal sphincter (EAS) and PRM was initially recorded. Subsequently rectal wall tone was assessed by a barostat system during rectal infusion with normal saline at 30 degrees C and at 4 degrees C with simultaneous electromyography (EMG). RESULTS: There was a significant increase in EMG activity of the EAS and PRM on strain- ing (p<0.001), suggestive of anismus, in 10 of 28 patients and 0 of 15 controls. Rectal tone in controls did not respond to saline infusion at 30 degrees C, but it increased at 4 degrees C (p<0.05). Similarly, in constipated patients rectal tone did not respond to rectal saline infusion at 30 degrees C, but infusion at 4 degrees C increased tone in all 10 patients with anismus (p<0.05); EMG activity of the EAS and PRM also increased (p<0.001). In the remaining 18 patients, rectal tone after saline infusion at 4 degrees C remained unchanged. CONCLUSIONS: Rectal infusion with iced saline increased rectal tone in healthy controls and constipated patients with anismus while it had no effect in the remaining patients. Lack of increase of rectal tone may be secondary to rectal inertia. According to these preliminary observations, the rectal cooling test may be useful in differentiating between rectal inertia and anismus.

Effect of different types of textiles on pregnancy.

PURPOSE OF INVESTIGATION: The effect of different types of textiles on pregnancy was studied in 35 pregnant bitches divided equally into one control and four experimental groups. METHODS: During pregnancy, the test groups were dressed in a garment made of either pure polyester, cotton or wool, or of a 50/50% polyester-cotton mix. Serum estradiol 17 B and progesterone were measured before and every 15 days during pregnancy. Electrostatic potential (EP) was assessed on the skin before and after wearing the garment. RESULTS: The bitches wearing cotton, wool and polyester-cotton mix as well as five of the seven wearing pure polyester garments had normal serum estradiol and progesterone during pregnancy and produced normal offspring. The remaining two animals of the group wearing pure polyester showed low serum progesterone levels in the first month of pregnancy and had spontaneous abortions. Mating was attempted in these two bitches during the subsequent estrous cycle without making them wear polyester garments. Serum levels of reproductive hormones were normal and they produced normal offspring. EP was detected on the skin of only the polyester-dressed groups, and was higher in the pure than in the mixed polyester groups. CONCLUSIONS: The cause of low serum progesterone and abortion in the two bitches is unknown. Abortion seemed to be due to the low serum progesterone which may have resulted from the injurious effect of EP on the ovarian or placental function.

A study on the etiology of uterine pressure rise on semen deposition in the vagina or uterus.

PURPOSE OF INVESTIGATION: In a recent study we have demonstrated that semen deposition into the vagina or uterus effects uterine pressure rise which is suggested to assist in "sucking" semen into the uterine cavity. The purpose of this study was to investigate whether the uterine pressure rise is effected by the sperm or the substances contained in the seminal plasma, and to test the response of the vagina and uterus to abnormal semen deposition. METHODS: Semen was obtained from 60 men divided into four groups: A) obstructive azoospermia, B) Sertoli cell-only syndrome, C) oligozoospermia and D), fertile subjects. Before and after semen deposition into the vagina and uterus both vaginal and uterine pressure were recorded. RESULTS: Semen from groups A and B produced no significant vaginal or uterine pressure changes (p > 0.05) when it was deposited into either the vagina or uterus. Group C and D semen when placed in the vagina or uterus separately effected significant intrauterine pressure rise (p < 0.05) but no vaginal pressure changes (p > 0.05). The pressure rise was higher when the semen was deposited in the uterus than in the vagina (p < 0.05) and with the normospermic than oligozoospermic semen (p < 0.05). In groups C and D, the seminal plasma produced no vaginal or uterine pressure changes (p > 0.05), whereas the sperm effected intrauterine pressure rise (p < 0.05) which was more elevated with sperm from normospermic than oligozoospermic semen (p < 0.05). CONCLUSIONS: Aspermic semen did not effect vaginal or uterine pressure rise, while oligozoospermic and normospermic semen produced rise of uterine but not vaginal pressure. Uterine pressure rise was induced by the sperm and not the seminal plasma. Further studies are required to define the sulstances secreted by the sperm which produce this increased uterine pressure.

Vaginal and uterine pressure response to semen deposition into the vagina and uterus: human study.

PURPOSE OF INVESTIGATION: The effect of semen deposition in the vagina or uterine cavity on both uterine and vaginal pressure has scarcely been reported in the literature. We investigated the hypothesis that semen deposition in the vagina or uterus effects changes in their pressure. METHODS: The study comprised 27 healthy women volunteers (mean age 36.4 +/- 11.6 years). Both uterine and vaginal pressure were measured under basal conditions and on semen or saline deposition in the vagina and uterus. RESULTS: Upon semen deposition in the vagina, the vaginal pressure showed no significant changes (p > 0.05) while the uterine pressure exhibited a significant intermittent rise (p < 0.05). Semen deposition into the uterine cavity caused no vaginal pressure changes (p > 0.05) while the uterine pressure exhibited an intermittent increase (p < 0.01). Saline injection into the vagina or uterus showed no significant pressure changes (p > 0.05). CONCLUSION: Semen deposition into the vagina or uterine cavity was associated with uterine pressure elevation that might eventually help transport the sperm to the oviduct. Further studies are required to define the substances responsible for this effect.

Sex hormone status in male rats after exposure to 50 Hz, 5 mTesla magnetic field.

The question of whether extremely low frequency magnetic fields can affect biological system has attracted attention. The theoretical possibility of such an interaction is often questioned and the site of interaction is unknown. The influence of extremely low frequency magnetic field of 50 Hz, 5 mTesla on sex hormone status was studied. 60 male albino rats were divided into 6 groups and were continuously exposed to 50 Hz, 5 mTesla magnetic field generated by magnetic field chamber for periods of 1, 2 and 4 weeks. For each experimental point, sham treated group was used as a control. Assay of serum testosterone LH, FSH, and prolactin were performed. Serum testosterone showed no significant changes. FSH showed significant increase than sham exposed group after 1 week magnetic field exposure. LH showed significant increase than sham exposed group only after 4 weeks magnetic field exposure, while serum prolactin hormone level showed a significant increase in all magnetic field exposed groups than sham exposed animals. Exposure to 50 Hz, 5 mTesla magnetic field for periods of 1, 2 and 4 weeks has no effect on testosterone level, some changes on FSH and LH serum levels and increase in serum prolactin level.

Interstitial cells of Cajal in erectile dysfunction.

The corpora cavernosa (CC) evokes electric activity. Slow waves (SWs) appear to originate from interstitial cells of Cajal (ICCs), which seem to control the activity of the smooth muscle cells (SMC). The ICCs were demonstrated to exist in the CC. We investigated the hypothesis that the ICC distribution differs with each of the various ED types. The study comprised 62 men with ED: 16 neurogenic (NGED), 15 arteriogenic (AGED), 11 venogenic (VGED) and 22 psychogenic (PGED). 15 volunteers with normal erections acted as controls. The patients underwent a complete diagnostic evaluation. A biopsy of 3 x 3 mm from the CC was subjected to C-kit immunohistochemistry examination. Specificity control of the antisera consisted of incubation of the tissue with normal rabbit serum substituted for the primary antiserum. C-kit positive stellate-appearing cells resembling those of ICC were detected in the controls. The branches were either laterally located (multipolar) or lying at each pole (bipolar). They were distinguishable from the SMC, which were C-kit negative. ICC were detected in all specimens from patients with NGED and VGED, absent in 13/15 with AGED and scanty in PGED. ICC distribution was different in the various types of ED. It is suggested that this distribution interferes with SW discharge and the control of SMC activity with a resulting ED.

Molecular andrology as related to sperm DNA fragmentation/sperm chromatin biotechnology.

Genetic male infertility occurs throughout the life cycle from genetic traits carried by the sperm, to fertilization and post-fertilization genome alterations, and subsequent developmental changes in the blastocyst and fetus as well as errors in meiosis and abnormalities in spermatogenesis/spermatogenesis. Genes encoding proteins for normal development include SRY, SOX9, INSL3 and LGR8. Genetic abnormalities affect spermatogenesis whereas polymorphisms affect receptor affinity and hormone bioactivity. Transgenic animal models, the human genome project, and other techniques have identified numerous genes related to male fertility. Several techniques have been developed to measure the amount of sperm DNA damage in an effort to identify more objective parameters for evaluation of infertile men. The integrity of sperm DNA influences a couple's fertility and helps predict the chances of pregnancy and its successful outcome. The available tests of sperm DNA damage require additional large-scale clinical trials before their integration into routine clinical practice. The physiological/molecular integrity of sperm DNA is a novel parameter of semen quality and a potential fertility predictor. Although DNA integrity assessment appears to be a logical biomarker of sperm quality, it is not being assessed as a routine part of semen analysis by clinical andrologists. Extensive investigation has been conducted for the comparative evaluation of these techniques. However, some of these techniques require expensive instrumentation for optimal and unbiased analysis, are labor intensive, or require the use of enzymes whose activity and accessibility to DNA breaks may be irregular. Thus, these techniques are recommended for basic research rather than for routine andrology laboratories.

Sperm DNA fragmentation.

Several techniques have been developed to measure the amount of sperm DNA damage in an effort to identify more objective parameters for evaluation of infertile men. The integrity of sperm DNA influences a couple's fertility and helps predict the chances of pregnancy and its successful outcome. The available tests of sperm DNA damage require additional large-scale clinical trails before their integration into routine clinical practice. The physiological/molecular integrity of sperm DNA is a novel parameter of semen quality and a potential fertility predictor. Although DNA integrity assessment appears to be a logical biomarker of sperm quality, it is not being assessed as a routine part of semen analysis by clinical andrologists. Extensive investigation has been conducted for the comparative evolution of these techniques. However, some of these techniques require expensive instrumentation for optimal and unbiased analysis, are labor intensive, or require the use of enzymes whose activity and accessibility to DNA breaks may be irregular. Thus, these techniques are recommended for basic research rather than for routine andrology laboratories. Sperm chromatin structure evaluation is applied to detect male factors that may affect the chance of success with IVF as well as natural fertility. Further research is needed to define the optimal test of sperm chromatin structure. The clinical application of this test will evolve as well.

Role of tunica albuginea in erection: is it a dynamic or a static role?

The tunica albuginea (TA) of the penis is claimed to share in erectile mechanism by compressing the emissary veins passing through it. Apparently this claim is theoretical as no experimental studies could be traced in literature proving this concept. We investigated the hypothesis that TA acts as a cover to corpora cavernosa (CC) and spongiosa (CS) and does not have an active role in erectile mechanism. Penises of 9 dogs were degloved and TA was divided at upper, middle and lower 1/3 of the penis. The intracorporal and glans penis (GP) pressures were measured in the TA-covered and non-covered parts of CC and CS in the flaccid and erectile phases. Sham operation, without performing the TA incisions, was done in 7 control animals. In the test animals, intracorporal pressure (ICP) in the non-TA covered corpora and in GP recorded in flaccid phase a mean of 12.2 +/- 0.8 cmH2O for CC and 11.3 +/- 0.7 cmH2O for the CS and GP, and in the erectile phase 98.4 +/- 8.6 and 76.2 +/- 9.3 cmH2O, respectively. There was no significant difference between covered and non-covered corpora or between test and control animals. In conclusion, the TA seems to act as a cover to the corporal tissue. Its absence did not change ICP.

Histologic study of the tunica albuginea of the penis and mode of cavernosus muscles' insertion in it.

The tunica albuginea (TA) is the outer covering of the corpora cavernosa (CCs) and corpus spongiosum (CS) of the penile shaft. The different histoanatomical patterns of the TA, as well as the mode of attachment of the ischio-/bulbo-cavernosus muscles (ICM, BCM) to the TA, were studied, aiming at elucidating their role in the mechanism of erection. Twenty-eight cadaveric specimens (18 adults, 10 neonatal deaths) were studied morphologically and histologically after staining with hematoxylin and eosin and Verhoeff-van Gieson stains. The TA consisted in 20 specimens of 2 layers: inner circular and outer longitudinal, in 6 specimens of 3 layers: inner circular, longitudinal and outer circular, and in 2 of only one longitudinal layer. The CS TA was formed of one layer of longitudinal fibers. The mode of cavernosus muscles insertion into the TA revealed 3 patterns. The conjoint BCM and ICM formed a fibrous belt over the CCs in 18 specimens, a muscular belt in 6 and no belt in 4. The functional role of the variations in the TA morphological structure is not exactly known. We hypothesize that the 3-layered TA gives more penile rigidity than the double and single layers. Considering the type of cavernosus muscles insertion into the TA, it appears that the fibrous belt exerts more CC compression than the other 2 types of insertion.

Tunica albuginea overlapping: a novel technique for the treatment of erectile dysfunction.

Tunica albuginea (TA) in venogenic erectile dysfunction (VED) was found subluxated and flabby because of degeneration and atrophy of its collagen fibres. This had apparently led to derangement of TA veno-occlusive mechanism. We investigated the hypothesis that overlapping of the subluxated and flabby TA would achieve a competent veno-occlusive mechanism during erection. Tunical overlapping was performed in nine VED patients (age 35.6 +/- 1.6 years). Intracorporal pressure (ICP) was measured pre- and postoperatively. After penile degloving, TA on lateral penile aspect was divided along whole length of corpus cavernosum (CC) and tunical double-breasting for 1-1 1/2 cm was performed. A biopsy was taken from TA and stained with haematoxylin and eosin and Masson's trichrome. Clinical efficiency of the operation was evaluated after 6 months. ICP increased (P < 0.01) postoperatively in the nine patients. The increase was maintained during follow-up period in eight patients and decreased to preoperative level in one. Six months after operation, the eight patients had significantly (P < 0.01) improved scores for the erectile function domain over the preoperative scores. Microscopic examination of TA biopsies showed atrophy of the collagen fibres. Tunical overlapping aims at correction of TA flabbiness, corporal tissue support and improving of veno-occlusive mechanism.

Urethral sphincters response to cavernosus muscles stimulation with identification of cavernoso-urethral reflex.

The functional activity of the urethral sphincters during cavernosus muscles' contraction at coitus has been poorly addressed in the literature. We investigated the hypothesis that cavernosus muscles' contraction affects reflex contraction of the urethral sphincters to guard against semen reflux into the urinary bladder or urine leakage from the bladder during orgasm and ejaculation. The electromyographic (EMG) response of the external (EUS) and internal (IUS) urethral sphincters to ischio- (ICM) and bulbo- (BCM) cavernosus muscle stimulation was studied in 15 healthy volunteers (9 men, 6 women, age 39.3 +/- 8.2 SD years). An electrode was applied to each of ICM and BCM (stimulating electrodes) and the 2 urethral sphincters (recording electrodes). The test was repeated after individual anesthetization of the urethral sphincters and the 2 cavernosus muscles, and after using saline instead of lidocaine. Upon stimulation of each of the 2 cavernosus muscles, the EUS and IUS recorded increased EMG activity. Repeated cavernosus muscles' stimulation evoked the urethral sphincteric response without fatigue. The urethral sphincters did not respond to stimulation of the anesthetized cavernosus muscles nor did the anesthetized urethral sphincters respond to cavernosus muscle stimulation. Saline infiltration instead of lidocaine did not affect the urethral sphincteric response to cavernosal muscle stimulation. Results were reproducible. Cavernosus muscles' contraction is suggested to effect EUS and IUS contraction. This action seems to be reflex and mediated through the 'cavernoso-urethral reflex.' Urethral sphincters contraction upon cavernosus muscles contraction during sexual intercourse presumably prevents urine leak from the urinary bladder to urethra, prevents retrograde ejaculation, and propels ejaculate from the posterior to the penile urethra. The cavernoso-urethral reflex can act a diagnostic tool in the investigations of patients with ejaculatory disorders.