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D Turini

Publications and source records attributed to D Turini.

At least 19 recordsLinked to original sources
PubMed2001

Long-term outcome of urethroplasty after failed urethrotomy versus primary repair.

PURPOSE: A urethral stricture recurring after repeat urethrotomy challenges even a skilled urologist. To address the question of whether to repeat urethrotomy or perform open reconstructive surgery, we retrospectively review a series of 93 patients comparing those who underwent primary repair versus those who had undergone urethrotomy and underwent secondary treatment. MATERIALS AND METHODS: From 1975 to 1998, 93 males between age 13 and 78 years (mean 39) underwent surgical treatment for bulbar urethral stricture. In 46 (49%) of the patients urethroplasty was performed as primary repair, and in 47 (51%) after previously failed urethrotomy. The strictures were localized in the bulbous urethra without involvement of penile or membranous tracts. The etiology was ischemic in 37 patients, traumatic in 23, unknown in 17 and inflammatory in 16. To simplify evaluation of the results, the clinical outcome was considered either a success or a failure at the time any postoperative procedure was needed, including dilation. RESULTS: In our 93 patients primary urethroplasty had a final success rate of 85%, and after failed urethrotomy 87%. Previously failed urethrotomy did not influence the long-term outcome of urethroplasty. The long-term results of different urethroplasty techniques had a final success rate ranging from 77% to 96%. CONCLUSIONS: We conclude that failed urethrotomy does not condition the long-term result of surgical repair. With extended followup, the success rate of urethroplasty decreases with time but it is in fact still higher than that of urethrotomy.

Adolescent↗
PubMed2000

Characterization of bradykinin B(2) receptor antagonists in human and rat urinary bladder.

The effect of three selective bradykinin B(2) receptor antagonists, MEN11270 (H-DArg-Arg-Pro-Hyp-Gly-Thi-c(Dab-DTic-Oic-Arg)c(7gamma-1 0alpha)), Icatibant (H-DArg-Arg-Pro-Hyp-Gly-Thi-Ser-DTic-Oic-Arg-OH), and FR173567 ((E)-3-(6-acetamido-3-pyridyl)-N-[N-[2, 4-dichloro-3-[(2-methyl-8-quinolinyl) oxymethyl] phenyl]-N-methylaminocarbonylmethyl]acrylamide) was evaluated in the human and rat urinary bladder in vitro and in vivo in anaesthetized rats. Bradykinin evoked a concentration-dependent contraction of human (pD(2)=7.2) and rat (pD(2)=7.7) detrusor muscle strips. In human preparations, all the antagonists tested produced a rightward-shift in the concentration-response curve for bradykinin. Schild plot analysis yielded pK(B) values of 8.4, 8.4 and 8.6 for MEN11270, Icatibant, and FR173567, respectively. In the rat preparations the three antagonists (at 100 nM concentration), produced a shift to the right which gave apparent pA(2) values of 8. 2, 8.0 and 8.1 for MEN11270, Icatibant, and FR173567, respectively. In anaesthetized rats, both MEN11270 and Icatibant (1-10 nmol/kg i.v. ) dose dependently reduced the bradykinin (100 nmol/kg i.v.)-induced urinary bladder contraction, their effect being prompt and long-lasting. In contrast, FR173567 (100 nmol/kg i.v.) produced a partial and short-lasting inhibition of bradykinin-induced bladder contractions. The present findings indicate that all the antagonists tested recognize with similar potencies the bradykinin B(2) receptors expressed in the detrusor muscle of both humans and rats. MEN11270 and Icatibant possess a higher potency and longer duration of action in vivo than FR173657, suggesting that the activity of this non-peptide antagonist in vivo is hampered by factors unrelated to its affinity for bradykinin B(2) receptors.

Aged↗
PubMed2000

Intravesical resiniferatoxin for the treatment of hypersensitive disorder: a randomized placebo controlled study.

PURPOSE: Present therapeutic approaches to control hypersensitive disorder of the lower urinary tract and bladder pain are clinically and scientifically unsatisfactory. We performed a randomized placebo controlled study with followup after 1 and 3 months using intravesical resiniferatoxin to treat hypersensitive disorder and bladder pain. MATERIALS AND METHODS: We prospectively randomized 18 patients into 2 groups to receive a single dose of 10 nM. resiniferatoxin intravesically (group 1) or a placebo saline solution only (group 2). All patients had at least a 6-month history of frequency, nocturia, urgency and symptoms of pelvic pain as well as no urinary tract infection within the last 3 months, functional disorders of the lower urinary tract, or other vesical or urethral pathology. Pretreatment voiding pattern and pain score were recorded. Patients were evaluated after 30 days (primary end point) and 3 months (secondary end point). RESULTS: The 2 groups were adequately homogeneous in regard to patient age, sex ratio, disease duration, voiding pattern and pain score. At the primary end point mean frequency plus or minus standard error of mean was decreased from 12. 444 +/- 0.70 voids to 7.111 +/- 0.67 and nocturia from 3.777 +/- 0. 27 to 1.666 +/- 0.16 (p <0.01). We observed a lesser significant improvement in mean frequency in group 1 at the secondary end point to 10.444 +/- 0.94 voids (p <0.05). No significant modification was noted in patients assigned to placebo. Mean pain score significantly decreased in group 1 at the primary end point from 5.555 +/- 0.29 to 2.666 +/- 0.23 (p <0.01) but not at the secondary end point (4.777 +/- 0.66, p >0.05). No statistically significant improvement in mean pain score was observed in placebo group 2. During resiniferatoxin infusion 4 group 1 patients noticed a light warm or burning sensation at the suprapubic and/or urethral level. CONCLUSIONS: Intravesical resiniferatoxin may significantly improve the voiding pattern and pain score in patients with hypersensitive disorder and bladder pain. Because resiniferatoxin did not cause a significant warm or burning sensation at the suprapubic and/or urethral level, it may be considered a new strategy for treating hypersensitive disorder and bladder pain. However, further studies are necessary to confirm our results and define the resiniferatoxin mechanism of action, dose and necessary treatment schedule.

Administration, Intravesical↗
PubMed1999

Urodynamic assessment during intravesical infusion of capsaicin for the treatment of refractory detrusor hyperreflexia.

PURPOSE: Parameters to predict outcome and the urodynamic effects during infusion of capsaicin, seem not to have been assessed in patients with chronic cord injury. We monitored bladder activity urodynamically during infusion of high dosage of capsaicin. MATERIAL AND METHODS: Thirty patients, 18 women and 12 men (average age 29 years, range 20-59 years), suffering from chronic spinal myelopathy, who presented a refractory detrusor hyperreflexia, were studied. They received saline solution containing 10(-3) M capsaicin at a flow rate of 2 ml min(-1) for 15 min (total volume 30 c.c.). The detrusor activity was monitored by a real-time cystometrogram during infusion and 15 min after the end of the infusion itself. New filling cystometrograms were recorded after 30 days and after 6 months. RESULTS: We obtained a clinical and significant urodynamic improvement in 15 of the 30 patients (50%), confirming that intravesical capsaicin may represent a therapeutic option for a selected group of patients suffering from refractory detrusor hyperreflexia due to chronic spinal upper motor neuron lesion. Best results were observed in patients who showed, during the infusion of capsaicin, early uninhibited bladder contractions which disappeared within 10-12 min from the beginning of the infusion (desensitisation). The patients of this group presented a significant increase of mean cystomanometric capacity after 6 months (from 190.7 to 396.7 ml). No significant clinical or urodynamic improvement was observed in the group of patients in whom uninhibited activity of detrusor was recorded for all the time of infusion. CONCLUSION: Our results support the idea of a major complexity of spinal reflex in paraplegic patients and may offer a clue to explain the failure of therapy with capsaicin. The present results support a new approach in the treatment of detrusor hyperreflexia. The ideal dosage and treatment interval are not at present established and further studies are needed to explain substantial differences in the outcome according to different urodynamic responses.

Adult↗
PubMed1998

Excitatory motor and electrical effects produced by tachykinins in the human and guinea-pig isolated ureter and guinea-pig renal pelvis.

1. In isolated tissue experiments, neurokinin A (NKA) produced concentration-dependent contraction of human and guinea-pig ureter (pD2 = 6.7 and 7.2, respectively); an effect greatly reduced (>80% inhibition) by the tachykinin NK2 receptor-selective antagonist MEN 11420 (0.1 microM). The tachykinin NK1 and NK3 receptor agonists septide and senktide, respectively, were ineffective. 2. Electrical field stimulation (EFS) of the guinea-pig isolated renal pelvis produced an inotropic response blocked by MEN 11420 (0.01-1 microM). In the same preparation MEN 11420 (0.1 microM) blocked (apparent pK(B) = 8.2) the potentiation of spontaneous motor activity produced by the NK2 receptor-selective agonist [betaAla8]NKA(4-10). 3. In sucrose-gap experiments, EFS evoked action potentials (APs) accompanied by phasic contractions of human and guinea-pig ureter, which were unaffected by tetrodotoxin or MEN 11420 (3 microM), but were blocked by nifedipine (1-10 microM). NKA (1-3 microM) produced a slow membrane depolarization with superimposed APs and a tonic contraction with superimposed phasic contractions. NKA prolonged the duration of EFS-evoked APs and potentiated the accompanying contractions. MEN 11420 completely prevented the responses to NKA in both the human and guinea-pig ureter. 4. Nifedipine (1-10 microM) suppressed the NKA-evoked APs and phasic contractions in both human and guinea-pig ureter, and slightly reduced the membrane depolarization induced by NKA. A tonic-type contraction of the human ureter in response to NKA persisted in the presence of nifedipine. 5. In conclusion, tachykinins produce smooth muscle excitation in both human and guinea-pig ureter by stimulating receptors of the NK2 type only. NK2 receptor activation depolarizes the membrane to trigger the firing of APs from latent pacemakers.

Aged↗
PubMed1998

Intravesical resiniferatoxin for the treatment of detrusor hyperreflexia refractory to capsaicin in patients with chronic spinal cord diseases.

OBJECTIVE: Resiniferatoxin (RTX), a substance isolated from some species of Euphorbia, a cactus-like plant, shows pharmacological effects similar to those of capsaicin. We have studied the possibility of treating detrusor hyperreflexia refractory to intravesical capsaicin in patients with chronic spinal cord injuries, thereby providing insight into the mechanism of action of RTX on sensory neurons and its possible future pharmacological and clinical use. MATERIALS AND METHODS: RTX saline solution (30 ml at a concentration of 10(-5) M) was instilled into the bladder of 7 patients with detrusor hyperreflexia, refractory to intravesical capsaicin therapy, and left in place for 30 min. Effects on bladder function were monitored during the treatment and at follow-up (15 days and 4 weeks later). RESULTS: Fifteen days after RTX, the mean cystomanometric capacity increased significantly from 190 ml +/- 20 ml to 407.14 ml +/- 121.06 (p < 0.01), and it remained high four weeks later (421.66 +/- 74.40 p < 0.01). After 15 days, four patients had a pharmacologically induced detrusor areflexia. They emptied their bladders by clean intermittent catheterization. After four weeks, only two patients still had a pharmacologically induced detrusor areflexia. Clinically, three patients remained dry, and the other three reported a significant improvement in their incontinence and symptoms (frequency, urgency and nocturia). CONCLUSIONS: By interfering with sensory unmyelinated fibers, intravesical RTX seems to be a promising treatment option for selected cases of detrusor hyperreflexia. The ideal dosage and treatment interval have not yet been established, and further studies are necessary to confirm our preliminary results.

Administration, Intravesical↗
PubMed1997

Urodynamic effects of intravesical resiniferatoxin in humans: preliminary results in stable and unstable detrusor.

PURPOSE: Resiniferatoxin, a substance isolated from some species of euphorbia, a cactus-like plant, presents pharmacological effects similar to those of capsaicin. We studied the urodynamic effects of intravesical resiniferatoxin* in normal subjects and patients with unstable detrusor contraction to provide insight into the action mechanism of the molecule on sensory neurons and possible future pharmacological and clinical use. MATERIALS AND METHODS: A total of 15 subjects with normal (8 patients) or unstable detrusor muscle (1 with detrusor instability and 6 with detrusor hyperreflexia) underwent urodynamic assessment during and after intravesical instillation of resiniferatoxin. Volume required to elicit the first desire to void, maximum bladder capacity and maximum bladder pressure were recorded during instillation of resiniferatoxin at a flow rate of 20 ml. per minute (normal subjects) or 15 minutes after instillation of 30 cc of a saline solution containing 10(-8) M. of resiniferatoxin and kept for 30 minutes in patients with unstable detrusor. The experiment was examined by the analysis of variance for repeated measures and post hoc comparisons were performed by Tukey-Kramer procedure. A p value <0.05 was accepted as significant. RESULTS: Resiniferatoxin did not decrease the volume required to elicit the first desire to void and did not produce warm or burning sensations at the suprapubic/urethral level during infusion in subjects with normal detrusor function. In patients with bladder hyperactivity mean bladder capacity increased from 175.28 ml. plus or minus standard deviation 36.05 to 280.85 ml. plus or minus standard deviation 93.33 (p <0.01) immediately after treatment, and no significant modification of bladder pressure was recorded. Four weeks after treatment, bladder capacity remained increased in 2 patients but mean capacity did not increase significantly from 175.28 ml. plus or minus standard deviation 36.053 to 216.71 plus or minus standard deviation 86.91. The 2 patients with stable increase of bladder capacity reported significant clinical improvement of frequency, nocturia and incontinence 4 weeks later. CONCLUSIONS: Our results suggest that in humans there may be substantial differences in urodynamic effects between resiniferatoxin and capsaicin when the drugs are instilled into the bladder. Further studies, in vitro and in vivo, are necessary to define the pharmacological and clinical effects of resiniferatoxin. Because resiniferatoxin did not produce warm or burning sensations at the suprapubic/urethral level during infusion and seems to have rapid desensitization, it could be an interesting alternative to intravesical capsaicin in the treatment of select cases of bladder hyperactivity.

Administration, Intravesical↗
PubMed1997

Tachykinin NK1 and NK2 receptors mediate non-adrenergic non-cholinergic excitatory neuromuscular transmission in the human ileum.

Tachykinin NK1 and NK2 receptor selective antagonists and agonists were used to study excitatory non-adrenergic non-cholinergic (NANC) transmission in circular muscle strips from human ileum by the sucrose-gap method. In the presence of atropine (1 microM), guanethidine (3 microM), indomethacin (3 microM), apamin (0.1 microM), and N omega-nitro-L-arginine (L-NOARG, 30 microM), electrical field simulation (EFS) produced a NANC inhibitory junction potential (i.j.p.) followed by NANC excitatory junction potential (e.j.p.) with superimposed action potentials and contraction of the circular muscle of human ileum. The selective tachykinin NK1 receptor antagonist, GR 82334 (0.1-3 microM) produced a concentration-dependent inhibition of the EFS-evoked NANC e.j.p. (IC50 = 0.21 microM) and contraction (IC50 = 0.21 microM). The selective tachykinin NK2 receptor antagonist, MEN 10627 (0.01-1 microM), likewise produced a concentration-dependent inhibition of the EFS-evoked NANC e.j.p. (IC50 = 0.07 microM) and contraction (IC50 = 0.03 microM). Either antagonist was more effective in inhibiting the mechanical than the electrical response to EFS. Neither GR 82334 nor MEN 10627 had any effect on the apamin- and L-NOARG-resistant NANC i.j.p. Activation of the NK1 or NK2 receptors by the selective receptor agonists, [Sar9]substance P (SP) sulfone and [beta Ala8]neurokinin A (NKA) (4-10), respectively (0.3 microM for 20 s each), produced depolarization with superimposed action potentials and contractions. GR 82334 selectively inhibited the responses to [Sar9]]SP sulfone, without affecting the responses to [beta Ala8]NKA (4-10). MEN 10627 inhibited the responses to [beta Ala8]NKA (4-10), without affecting the responses to [Sar9]SP sulfone. We conclude that both tachykinin NK1 and NK2 receptors co-operate in producing NANC excitation and contraction of the circular muscle in human ileum.

Aged↗
PubMed1997

Iatrogenic external iliac artery disruption during open pelvic lymph node dissection: successful repair with hypogastric artery transposition.

We report the first case of a wide, iatrogenic, proximal disruption of the right external iliac artery, occurring during staging open lymph node dissection for prostate cancer, which was repaired by hypogastric artery transposition. The hypogastric artery was mobilized and rotated anteriorly, and sutured to the distal segment of the external iliac artery. This is a feasible, innovative and safe technique which permits, by a single anastomosis, the secure reconstruction of a vascular axis to the leg when other procedures are not accessible.

Arteries↗
PubMed1996

Effect of several bicyclic peptide and cyclic pseudopeptide tachykinin NK2 receptor antagonists in the human isolated urinary bladder.

1. We have studied several tachykinin NK2 receptor antagonists, bearing a monocyclic pseudopeptide (MEN 10,508, MEN 10,573, MEN 10,581, MEN 10,612, MEN 10,619 and MEN 10,677), or bicyclic peptide (MEN 10,627, MEN 10,692, MEN 10,771, MEN 10,882 and MEN 10,993) structure, on the human isolated urinary bladder detrusor muscle against neurokinin A as an agonist, and compared their affinities in this preparation with those for NK2 receptors expressed in the rabbit isolated pulmonary artery and hamster isolated trachea. 2. In the human bladder, all the antagonists tested produced a concentration-dependent and competitive antagonism of neurokinin A-mediated contractions: among the cyclic pseudopeptides MEN 10,677 (pKB = 8.0) was the most potent antagonist, while among the bicyclic analogues it was MEN 10,993 (pKB = 8.8). 3. In general, the bicyclic peptide antagonists tested were more potent than the monocyclic pseudopeptide compounds, either in the human urinary bladder or in the rabbit pulmonary artery or hamster trachea, showing a nanomolar affinity for the human NK2 receptor. 4. A highly significant correlation was found between the estimated pKB values of all the antagonists tested in the human urinary bladder and rabbit pulmonary artery (r2 = 0.94, n = 12, P < 0.01), whereas no linear correlation was found between pKB values measured in the human urinary bladder and hamster trachea (r2 = 0.52, n = 12, P > 0.05): these observations provide further pharmacological evidence for receptor homology between the human and rabbit NK2 receptor. 5. The present results point out the class of NK2 receptor antagonists bearing a bicyclic peptide structure, like MEN 10,627, as candidates for testing in pathological conditions, such as bladder hyperactivity, for which preclinical evidence indicates that a therapeutic effect could result from the block of the tachykinin NK2 receptor.

Aged↗
PubMed1996

Intravesical capsaicin for treatment of severe bladder pain: a randomized placebo controlled study.

PURPOSE: Present therapeutic approaches to control bladder pain are clinically and scientifically unsatisfactory, and pain in the lower urinary tract remains a challenge even to the skilled urologist. A randomized placebo controlled study was done to evaluate intravesical capsaicin for severe bladder pain. Followup was 6 months. MATERIALS AND METHODS: A total of 36 patients was prospectively randomized into those receiving 10 microM. intravesical capsaicin twice weekly for 1 month (group 1) or placebo (group 2). All patients had pelvic pain for at least 6 months, and had no urinary tract infection within the last 3 months, functional disorders of the lower urinary tract, or other vesical or urethral pathology. Pretreatment voiding pattern and pain score were recorded. Patients were evaluated immediately at the end of treatment (primary end point) and 6 months later (secondary end point). RESULTS: Both groups were adequately homogeneous with regard to age, sex ratio, duration of disease, voiding pattern and pain score. At both end points group 1 had significant improvement in frequency and nocturia but no improvement in urgency. No change was noted in group 2. A significant decrease in pain score was found in group 1 at the primary (mean plus or minus standard deviation 3.22 +/- 0.42, p < 0.01) and secondary (3.83 +/- 0.47, p < 0.01) end points compared to before treatment (5.61 +/- 0.40, chi-square with 2 degrees of freedom 29.25, p < 0.0001). A significant improvement was also observed in the placebo group, in which the pretreatment pain score (5.47 +/- 0.37) was decreased at the primary (4.47 +/- 0.36, p < 0.01) and secondary (4.48 +/- 0.34, p < 0.01, chi-square with 2 degrees of freedom 12.71, p < 0.002) end points. There were no statistically significant differences between the 2 groups. CONCLUSIONS: We confirmed the beneficial effect of intravesical instillation of capsaicin on voiding pattern in patients with hypersensitive disorders (frequency and nocturia). We could not confirm improvement in pain score after capsaicin treatment compared to placebo. Possibly a larger dose of capsaicin would be more effective in controlling pain and neurological disease of the bladder.

Administration, Intravesical↗
PubMed1995

Gastropyeloplasty: an alternative procedure in reconstruction of the renal pelvis.

We report our first experience with the use of a small gastric patch for reconstruction of the renal pelvis. We performed left gastropyeloplasty based on the right gastroepiploic artery in 1 patient suffering from recurrent urinary tract infections and renal stones, and moderate renal failure. The use of a gastric patch for reconstruction of the renal pelvis prevented the recurrence of calculi and bacterial infections, and produced an improvement in renal function. We confirm the feasibility of the use of a small gastric patch in reconstruction of the renal pelvis and we argue that there are several possible ways to use stomach in upper urinary tract reconstruction.

Female↗
PubMed1995

Vesical-renal reflex: diuresis and natriuresis activated by intravesical capsaicin.

In the last years the role of capsaicin sensitive innervation, in the activation of the micturition reflex, has been reported in many papers. In our experience, upon the intravesical administration of capsaicin in humans, we noticed an increase of diuresis. No interaction is known about the sensory innervation of the bladder and renal function, so we studied the possibility of the existence of a vesical-renal reflex arc. Twenty-one patients (9 men and 12 women) were randomised to receive intravesical infusion of saline solution containing 10 microM capsaicin. Urine output, glomerular renal filtrate (GRF) and effective plasma renal flow (EPRF), measured by Technetium-99m diethylenetetramine-penta-acetic acid (DTPA) renal scintigraphy, were recorded over twenty minutes before and after the intravesical administration of capsaicin. Urine density, [Na+] and [K+] concentration, and prostaglandin E2 excretion were also determined before and after intravesical administration of capsaicin or vehicle. Installation of saline solution containing 10 microM capsaicin produced a significant increase of mean urine output, an increase of GRF, of EPRF and of [Na+] and [K+] urine concentration. An increase, not statistically significant, was observed of PgE2 excretion. None of the patients treated with vehicle showed any modification of parameters examined. The present findings demonstrate a hitherto unrecognized effect: increased diuresis following selective chemical stimulation of bladder efferents with capsaicin. The renal diuretic response to intravesical capsaicin represents a working hypothesis about the possible involvement of a vesical-renal reflex arc organized at spinal or supraspinal level.

Administration, Intravesical↗
PubMed1995

Vesical dysfunction in systemic sclerosis (scleroderma)

There have been only a few reports on the involvement of the urinary tract in patients with systemic sclerosis, a disease of the connective tissue characterized by thickening and fibrosis of the skin, abnormality of the small arteries, and involvement of the gastrointestinal tract, heart, lung and kidney. We report the urodynamic assessment and histological examination of 9 women with scleroderma. Three patients voided less than 100 ml. with a significant residual volume and 4 presented with detrusor areflexia during a filling cystometrogram. Histopathological examination in all patients with detrusor areflexia demonstrated the presence of arterial lesions and derangement of the capillary bed of the detrusor musculature. Our data provide evidence for the functional and histological involvement of the bladder in patients with systemic sclerosis.

Female↗
PubMed1994

The behavioral response induced by intravesical instillation of capsaicin rats is mediated by pudendal urethral sensory fibers.

The behavioral response induced by the intravesical instillation of capsaicin has been investigated in catheter-implanted, freely moving, conscious male and female rats. Intravesical instillation of capsaicin (25 nmol/rat in 0.5 ml) evoked an intense licking directed toward the lower abdominal and perineal skin which lasted for 15 min. Capsaicin-induced licking was reduced by systemic capsaicin pretreatment at a dose of 150 mg/kg but not at 50 mg/kg, administered 4 days before the intravesical instillation. Both doses of capsaicin effectively abolished the eye-wiping response to local capsaicin application. The capsaicin-induced licking was preserved (and prolonged) in both male and female animals subjected to bilateral ablation of the pelvic ganglia, 48 h before the intravesical instillation of the irritant. The capsaicin-induced licking was almost abolished by placing a ligature around the proximal urethra (24 h before), in order to avoid the contact of the irritant with the urethra or by previous section of the pudendal nerves (48 h before). One hour intravesical infusion with tetrodotoxin (1 and 10 microM) reduced the amplitude of micturition contractions but did not prevent the licking response evoked by capsaicin. On the contrary, the intravesical infusion of lidocaine (100 mM) abolished both micturition contractions and the capsaicin-induced licking. We conclude that the behavioral response induced by the intravesical instillation of capsaicin is mainly due to the stimulation of urethral afferents travelling within pudendal nerves.

Animals↗
PubMed1994

Intraurethrally infused capsaicin induces penile erection in humans.

Capsaicin-sensitive primary afferents widely innervate the genitourinary tract and play an important role in the integration of various mechanisms which activate reflexes leading to penile erection. We investigated the effect of intraurethral capsaicin infusion in psychogenically impotent men. The 20 patients were prospectively randomized to four groups, each of five men. Group A received intraurethral infusion of saline solution, group B intraurethral capsaicin (10(-5) M), group C intracavernosal papaverine hydrochloride (8 mg) plus intraurethral saline infusion, and group D intracavernosal papaverine hydrochloride (8 mg) plus intraurethral capsaicin (10(-5) M). The penile response was recorded real-time. Intraurethral capsaicin induced penile erection, as did the papaverine injection, while saline infusion was without effect. The erectile response to intraurethral infusion of capsaicin is suggested to involve activation of a urethra-corpora cavernosa reflex arc. Further studies are necessary to clarify if this arc is integrated at central nervous system level or is locally triggered, and if it may have pathophysiologic implications.

Capsaicin↗