Thomas Gerstenberg

Electrical activity of corpus cavernosum during flaccidity and erection of the human penis: a new diagnostic method?

We investigated 7 normal men and 1 diabetic patient with erectile dysfunction. Electromyography electrodes were placed in the corpus cavernosum of the penis and electrical activity was recorded during flaccidity. With sexual arousal the activity decreased and tumescence was initiated. During tumescence and full erection the electrical activity of the corpus cavernosum almost ceased but in the diabetic patient (neurogenic impotence) an increase was observed. This discoordination might be the cause of the erectile dysfunction. Recording the electrical activity of the corpus cavernosum in patients with suspected neurogenic erectile dysfunction could become clinically valuable, since this is the first test possible to study the function of the autonomic motor system that normally regulates penile function.

Non-cholinergic, non-adrenergic nerve mediated relaxation of trigone, bladder neck and urethral smooth muscle in vitro.

Human trigone and porcine urethral, bladder neck and trigone smooth muscle were exposed to transmural electric field stimulation in vitro. The responses were composed of different combinations of a relaxation phase and a contraction phase. A few strips exhibited contractions only and a few strips relaxation only. The individual strip retained the behavior throughout the experiment. No systematic difference in the responses was found in strips from the different regions. The configuration of the response was slightly shifted in favor of contraction by beta-adrenergic blockade with propanolol and prostaglandin synthesis inhibition with Ketoprofen. After alpha-adrenergic blockade with phentolamine and cholinergic blockade with atropine, the reverse effect was seen with augmentation of the relaxation and reduction of the contraction. The relaxation phase was completely abolished by nerve poisoning with tetrodotoxin, but was still observed with all other antagonists present, and was therefore nerve-mediated through non-cholinergic, non-adrenergic and non-prostaglandin transmitter or modulator systems.

Standardized Evaluation of Erectile Dysfunction in 95 Consecutive Patients

We investigated 95 patients referred for erectile dysfunction by penile blood pressure measurement, the intracavernous papaverine test and Doppler investigation of the penile arteries. Furthermore, penile cutaneous perception threshold, bulbocavernosus reflex latency and somatosensory cortical evoked potentials of the pudendal nerve were measured. In selected cases cavernosometry, cavernosography and corpus cavernosum electromyography were performed. Doppler investigation of the cavernous arteries after papaverine injection was more reliable than penile blood pressure measurement in the diagnosis of arteriogenic erectile dysfunction. Decreased sensibility of the penis may be the sole factor responsible for inability to sustain an erection. Erectile dysfunction may be provoked by impaired function of the pudendal nerve. Penile cutaneous perception threshold measurement and corpus cavernosum electromyography are mandatory in the evaluation of neurogenic etiology. Cavernosometry and cavernosography are reliable methods in the determination of abnormal drainage from the corpus cavernosum.

Intracavernous Self-Injection with Vasoactive Intestinal Polypeptide and Phentolamine in the Management of Erectile Failure

A total of 52 men, median age 55 years (range 28 to 74 years), with erectile failure was treated with vasoactive intestinal polypeptide and phentolamine. Impotence was classified as psychogenic in 3 patients, psychogenic/arteriogenic in 3, arteriogenic in 25, arteriogenic/neurogenic in 4, neurogenic in 5, venous leakage/psychogenic in 2, venous leakage/neurogenic in 1 and following venous leak surgery in 9. The patients were treated with 30 micrograms vasoactive intestinal polypeptide and 0.5 to 2.0 mg. phentolamine. A total of 1,380 self-injections was given and the number of injections per patient varied from 5 to 245. No patient had priapism, corporeal fibrosis or other serious complications. After sexual stimulation all patients obtained erection sufficient for penetration. Following ejaculation rigidity decreased normally. The median duration of treatment was 6 months (range 1 to 22). Nine patients discontinued treatment. One patient with severe arteriosclerosis experienced decreased effectiveness of the drug and received a penile prosthesis. Five patients elected not to perform self-injection any longer, 1 psychogenic impotent patient was cured, and 1 patient discontinued therapy due to palpitation and sweating. One patient died of a myocardial infarction not associated with this therapy.

Vasoactive Intestinal Polypeptide Influence on Lower Urinary Tract Smooth Muscle from Human and Pig

The influence of vasoactive intestinal polypeptide on detrusor, trigone, bladder neck and urethral smooth muscle from human and pig was investigated in vitro. Vasoactive intestinal polypeptide reduced the tension and amplitude of the spontaneous contractions of strips from all regions studied. Human detrusor and pig trigone, bladder neck and urethral strips were more sensitive to vasoactive intestinal polypeptide than pig detrusor. The response was reversible, reproducible and dose-dependent from 10(-9) to 10(-6) mol. per liter. The time to onset of the response was within 1/2 minute and the time to maximal relaxation was 2 to 10 minutes. The response was not affected by selective nerve poisoning with tetrodotoxin, beta-adrenergic blockade with propanolol or prostaglandin synthesis blockade with ketoprofen. Vasoactive intestinal polypeptide did not prevent prostaglandin E2 activity on the musculature. Contractions evoked by transmural electric field stimulation or pharmacologically with carbachol, noradrenaline, substance P and prostaglandin F2 alpha were equally reduced by VIP 10(-7) mol. per liter.

High flow infravesical obstruction in men: symptomatology, urodynamics and the results of surgery.

High flow infravesical obstruction in male patients with severe prostatism is defined by a maximum flow rate of more than 15 ml. per second and a vesical pressure exceeding 100 cm. water at maximum flow rate. During a 9-month period urodynamic screening of 225 patients referred to our hospital with prostatism revealed high flow infravesical obstruction in 16 (7 per cent). Transurethral surgery of the prostate or bladder neck was performed in 11 of the patients, with good results observed in symptomatology as well as in maximum flow rate. A urodynamic screening program is suggested to establish the diagnosis so that these patients can benefit from surgical treatment.

Vasoactive intestinal polypeptide (VIP) increases vaginal blood flow and inhibits uterine smooth muscle activity in women.

Abstract. The human vagina and uterus are heavily innervated by VIP‐containing nerve fibres. In the present study, we have measured vaginal blood flow, transmucosal oxygen tension and uterine smooth muscle activity during stepwise intravenous infusion of vasoactive intestinal polypeptide (VIP) (0, 100, 300, 900 pmol kg‐1 h‐1) in non‐pregnant women. Vaginal blood flow was measured by the heat clearance technique, transmucosal oxygen tension by an O2‐electrode and uterine activity by a micro‐tip pressure catheter in the uterine cavity. Arterial blood pressure, pulse frequency and the concentration of VIP in peripheral venous blood were monitored. VIP induced a concentration‐dependent increase in vaginal blood flow. The transmucosal oxygen tension was not significantly changed by VIP. The maximum dose of VIP decreased systolic as well as diastolic blood pressure and increased pulse frequency. VIP inhibited uterine activity. These findings suggest that VIP participates as a neurotransmitter in the control of genital physiological responses.

Intracavernosal injection of vasoactive intestinal polypeptide (VIP) does not induce erection in man per se

SummaryVasoactive intestinal polypeptide (VIP) was injected intracavernously in five normal subjects. Injections of 1, 5, 10 or 20 μg were given with a tourniquet at the base of the penis. In no instance was full tumescence or erection achieved. Visual sexual stimulation and vibration provoked full erection after all doses. Detumescence occurred in four after stimulation, but one man dad a 2-h-long erection after 20 μg of VIP. VIP is most probably the transmitter involved in relaxation of the trabecular smooth muscle. As it is involved to a lesser degree in dilatation of the penile artery, some degree of nervous stimulation is then required to obtain erection.

Prostaglandin Type E Activity Dominates in Urinary Tract Smooth Muscle in Vitro

Changes in isometric tension and spontaneous contractions in human and porcine lower urinary tract smooth muscle strips caused by PGE2, PGF2a and the prostaglandin biosynthesis inhibitor ketoprofen were investigated in vitro. Ketoprofen reduced the prostaglandin biosynthesis significantly and caused reversible and dose dependent decreases of tension and spontaneous contractions in detrusor strips, while tension increase was induced in strips from the urethra, bladder neck and trigone. PGE2 reestablished the tension and the spontaneous activity in the detrusor strips and counteracted the tension increase in strips from the urethra, bladder neck and trigone. PGF2a increased the tension in all strips. The threshold concentration for prostaglandin effect in strips pretreated with ketoprofen was 10(-10) - 10(-9) mol./l., a concentration which might be considered physiologically relevant. Prostaglandin synthesis inhibition thus caused responses opposite to those of PGE2 in every single strip. These results strongly suggest the PGE-type of activity to be more important than the PGF-type of activity in lower urinary tract smooth muscle in vitro.

Bladder Training and Terodiline in Females with Idiopathic Urge Incontinence and Stable Detrusor Function

Twenty consecutive female patients with urge incontinence and stable detrusor function on provocative rapid fill CO2-cystometry were treated as out-patients with a bladder training programme and with terodiline/placebo in a double-blind cross-over design. Frequency and incontinence episodes decreased significantly, while first sensation and cystometric bladder capacity increased. Both objectively and subjectively terodiline was significantly better than placebo with 50% (95% confidence limits 18-82) more patients improved on terodiline than on placebo. Thirty percent of the patients (95% confidence limits 12-54) relapsed after withdrawal of terodiline. At 3 months follow-up the remaining 70% were satisfied with the outcome of the training programme. Side effects were mild and reversible. Serum creatinine and alkaline phosphatase increased slightly on terodiline and the diastolic blood pressure was probably also increased by terodiline. In conclusion, female patients with idiopathic urge incontinence and stable detrusor function did respond to treatment as do female patients with urge incontinence and proven instability.