Mechanisms of veno-occlusion within and outside the canine corpus cavernosum penis using a pressure-flow technique and cavernoso-venography.

BACKGROUND: Physiological erection of the penis requires multiple mechanisms causing an increase in the arterial blood influx into, and decrease in the venous drainage out of the cavernous space. METHODS: We investigated the extent and location of the venous occlusion that occurs with penile erection within (intrinsic mechanism) and outside (extrinsic mechanism) the corpus cavernosum penis, using 15 adult male mongrel dogs. Under controlled flows produced by a combination of aortic ligation and constant infusion of saline into the corpus cavernosum penis, or into the deep dorsal vein, pressures within the cavernous space or deep dorsal vein were measured before and after electrical stimulation of the pelvic splanchnic (pelvic nerve), the hypogastric, and pudendal nerve. An increase in pressure following nerve stimulations represented an increase in outflow resistance due to occlusion of the venous system. Pre-and post-stimulation radiologic evaluations were performed to determine the site(s) of venous occlusion. RESULTS: Unilateral stimulation of the pelvic nerve caused leftward shift of the corporeal pressure-flow curve. Bilateral stimulation of the pudendal nerve caused a marked rise in deep dorsal vein pressure. CONCLUSIONS: Both intrinsic and extrinsic venous occlusion mechanisms exist and that the former is activated primarily by unilateral stimulation of the pelvic nerve and the latter by bilateral stimulation of the pudendal nerve. The occlusion site for the extrinsic mechanism was localized to where the dorsal vein penetrates the muscles at the base of the pelvis, whereas the precise site for the intrinsic mechanism could not be determined.

Suppression by prolactin of the electrically induced erectile response through its direct effect on the corpus cavernosum penis in the dog.

PURPOSE: Men become impotent when exposed to hyperprolactinemia. To clarify its mechanisms the effects of intracorporal infusion of prolactin on electrically induced penile erection were evaluated in 12 male dogs. MATERIALS AND METHODS: Prolactin (10 micrograms./ml.) or control saline was directly infused into the corpus cavernosum penis 5 minutes before electrical pulse stimulation of the pelvic nerve and the intracorporal pressure was monitored. RESULTS: In 8 dogs erection was markedly suppressed or completely abolished by prolactin. In the remaining 4, this effect of prolactin became manifest only when the ipsilateral internal pudenal artery was ligated. Saline infusion was without effect. CONCLUSIONS: An excess of prolactin directly inhibited the smooth muscle relaxation of corpus cavernosum penis.

[A case report of spontaneous renal rupture due to arteriosclerosis].

A case of spontaneous renal rupture with subcapsular hematoma was reported. The patient was a 44-year old man complaining of a sudden left flank pain without any recent history of trauma. His abdominal ultrasonography (US), computerized tomography (CT) and renal angiography demonstrated left renal rupture with subcapsular renal hematoma. Cytological examination of left upper urinary tract revealed a suspicion of a neoplasma of renal pelvis and left renal function was not recovered. Therefore, left total nephro-uretectomy was performed, and histological examination revealed hemorrhage and infarct due to the severe arteriosclerosis and intestinal nephritis without malignancy. Sixty-three cases of non-traumatic subcapsular renal hematoma reported previously in the Japanese literature are reviewed with some statistical analyses.

A foreign body of the corpus cavernosum in a patient with cleft glans penis: a case report.

We had an opportunity to treat a rare case of foreign body in the corpus cavernosum in a patient with cleft glans penis. The foreign body was a 13 cm wire, which was inserted by the patient himself for masturbation, and was removed surgically. To our knowledge, such a case has never been reported in the literature.

Participation of vasoactive intestinal polypeptide (VIP) as a humoral mediator in the erectile response of canine corpus cavernosum penis.

The ability of anti-vasoactive intestinal peptide (anti-VIP) serum to suppress the electrically induced relaxation of the corpus cavernosum was evaluated in vitro to define the role of VIP in penile erection. Strips of canine corpora cavernosa were placed in 5-ml organ chambers containing oxygenated Krebs-Ringer solution. They were stretched and fixed in place at both ends and pretreated with 2 x 10(-7)M noradrenaline (NA). NA was given to produce an optimal state of isometric smooth muscle contraction so that subsequent electrical field stimulation (EFS) could induce a good range of measurable relaxation response. This response was deemed to be an in vitro representation of penile erection. After NA treatment the cavernous tension rose markedly by 2-2.5 g; it then declined by up to 1-1.2 g upon EFS. Anti-VIP serum (1:16) or atropine sulfate (10(-6)M) was added at various time points between NA administration and EFS. When anti-VIP serum was administered, subsequent EFS-induced relaxation was attenuated by 20%-55% compared to the control EFS treatments. The degree of attenuation depended upon the frequency of EFS applied, being 20.6% +/- 4.0% at 20 Hz and 54.7% +/- 6.3% at 2 Hz. Atropine administered additionally following anti-VIP serum produced no further attenuation. However, atropine alone was capable of producing up to 23.7% +/- 3.5% attenuation. When anti-VIP serum was administered following atropine, the degree of attenuation that ensured was the sum of the attenuations produced by each of the two substances independently.(ABSTRACT TRUNCATED AT 250 WORDS)

Involvement of vasoactive intestinal peptide (VIP) as a humoral mediator of penile erectile function in the dog.

The effects of intracorporeal infusion of anti-vasoactive intestinal peptide (anti-VIP) antisera on electrically induced penile erection were studied in 18 male mongrel dogs. Electrical pulse stimulation (4 V, 4 milliseconds, 40 Hz) of the pelvic splanchnic nerve consistently produced penile erection ("electroerection"). Using this erection model, effects of anti-VIP serum were evaluated with regard to the peak intracorporeal pressure during electroerection. Pretreatment of the animals with repetitive intracorporeal infusion of anti-VIP rabbit serum completely abolished the electroerection in nine dogs, partially suppressed it (P < 0.01) in five, and was without effects in four. In contrast, control treatment of the same 18 dogs with normal rabbit serum was totally ineffective. In six dogs in which anti-VIP serum failed to produce a complete suppression of electroerection, 0.5 mg atropine sulfate was additionally given i.v. All six dogs exhibited significant (P < 0.01) suppression of the peak intracorporeal pressure after atropine. However atropine alone did not affect the intracorporeal pressure to any significant degree. To five of these six dogs with positive response to the combination treatment with anti-VIP serum and atropine, prazosin HCl was added i.v. It was found that prazosin HCl reversed the attenuation of electroerection produced by combined anti-VIP serum and atropine. Prazosin did not affect the intracorporeal pressure when administered following anti-VIP serum. These results suggest that VIP plays a role as a humoral mediator involved in penile erection and that there is a synergistic interaction between VIP and acetylcholine. Also it appears that the effect of acetylcholine but not that of VIP is mediated by the alpha-1 adrenergic mechanism.

Effects of hypogastric nerve and sympathetic chain stimulation on the pelvic nerve induced penile erection in the dog.

The effects of electrical stimulation of hypogastric nerve and sympathetic chain on 'electroerection' (penile erection induced by electrical stimulation of the pelvic nerve) were studied in dogs to clarify the physiological roles that these neural inputs may play in producing and/or maintaining penile erection. As an objective parameter of hemodynamics of the penile circulation, the pressure in the corpus cavernosum of the penis was measured. Hypogastric nerve electrostimulation was performed in 24 dogs who had received pelvic nerve stimulation and, therefore, had 'electroerection'. Ten dogs responded to this procedure with an augmentation of 'electroerection', 10 with an attenuation of 'electroerection', and 4 with no appreciable changes. 4 out of the 10 animals who exhibited an attenuation response were then given an alpha 1-adrenergic blocker (prazosin hydrochloride) prior to the electrical stimulation to evaluate the specificity of the effects of the hypogastric nerve stimulation. In 3 of the 4 dogs the attenuation effect was abolished by this treatment and instead an augmentation effect became evident. Sympathetic chain electrostimulation was performed in 6 dogs with 'electroerection'. When applied to the L4-5 interganglionic segment, it produced a biphasic response which consisted of an initial increase followed by a decrease of the intracorporeal pressure. In contrast, stimulation of the L2-3 interganglionic segment produced a monophasic response consisting of only augmentation of the intracorporeal pressure. These data suggested that there might be two groups of fibers in the hypogastric nerve and sympathetic chain which are functioning antagonistically, and that the anti-erectile neural inputs are mediated primarily by the alpha 1-adrenergic system. To examine the sites of penile vasculature where the innervating hypogastric nerve exerts its effects, electrical pelvic/hypogastric nerve stimulations were performed in dogs in whom the inflow blood circulation to the corpora cavernosa was disrupted by arterial ligation and replaced by a constant saline infusion. It appears that the stimulatory input via the hypogastric nerve caused an increased blood flow into the cavernous space due to vasodilation of the inflow blood vessels, and the inhibitory effect occurred mainly due to relaxation of the draining blood vessels with a resultant increase of the blood outflow from the cavernous space.

[Surgical management in synchronous bilateral renal cell carcinoma].

Six patients with synchronous bilateral renal cell carcinoma were treated surgically over a 7-year period in our department. They were all males and the mean age was 60.3 years. They comprised 7.1% of all patients with renal cell carcinoma encountered during the same period. In four out of the six cases, radical nephrectomy for the larger tumor plus partial nephrectomy for contralateral kidney was performed simultaneously. In the remaining two cases, bilateral partial nephrectomy was performed simultaneously or as separate procedures. Two patients required chronic hemodialysis and died of cardio-pulmonary insufficiency on the 70th and 75th day. One patient, who underwent bilateral partial nephrectomy with incomplete tumor removal, subsequently died of metastatic disease at 27 months. Although one of them required transient hemodialysis, the remaining three patients were alive and disease-free 84, 42, and 17 months after operation, without evidence of tumor. This series suggests that partial nephrectomy is an appropriate option in the management of selected cases of bilateral renal cell carcinoma.

Quantitative analysis of outflow pathway of corpora cavernosa by pressure flow technique.

Using a pressure flow technique, quantitative analysis of the physiological characteristics of the outflow pathway of the corpus cavernosum was carried out in 19 male dogs weighing 7.5 to 23.0 kg. Pressure flow curves were made on dogs whose pelvic nerve was stimulated electrically and on dogs left unstimulated. When a cyclical change in saline perfusion rate was applied without nerve stimulation, the variable of the intracorporeal pressure showed a large hysteretic loop, indicating that the resistance of the outflow canals to flow was altered by the distension of the sinusoidal space. In dogs whose pelvic nerve was stimulated, the pressure flow curves shifted to the left side in comparison with the outward phase of the pressure flow curve of animals without pelvic nerve stimulation, and this curve piled on the returning phase. No hysteretic relation was observed between the outward and returning phase of the pressure flow curve with pelvic nerve stimulation, but in the detailed analysis, in which the % flow rate was used instead of actual flow rate of saline perfusion, a small hysteretic loop based on the difference of the elasticity of the outlet canals was found. The distension of the corpora cavernosa and the pelvic nerve electrostimulation probably act as the triggers of the same occlusive mechanism in the outflow pathway. The percentage decrease in the blood flow in the outflow canal of the corpus cavernosum induced by the distension of the sinusoidal space or by the pelvic nerve electrostimulation was 69.6 +/- 14.4% (mean +/- SD).