Nitroxergic nerves mediate vagally induced relaxation in the isolated stomach of the guinea pig

Here we show that the relaxation induced by stimulation of the vagus nerve in the presence of cholinergic (muscarinic) and adrenergic blockade in the isolated stomach of the guinea pig is mediated by nitric oxide (NO). This is substantiated by inhibition of vagal relaxation by NG-monomethyl-L-arginine, an inhibitor of NO synthesis. The effect of NG-monomethyl-L-arginine was partially reversed by coincubation with L-arginine but not with D-arginine. NO activates soluble guanylate cyclase, and relaxation of the stomach induced by vagal stimulation was prevented by an inhibitor of soluble guanylate cyclase, methylene blue, further supporting our conclusions. The relaxant effect of vagal stimulation was also ablated by hexamethonium, an inhibitor of ganglionic nicotinic receptors, thereby showing that ganglionic transmission did not rely on NO, through its release from preganglionic neurons. However, hexamethonium did not inhibit the gastric relaxation brought about by increasing the intragastric pressure, which is also mediated by NO as previously described by us. The selective inhibition by hexamethonium of only the vagally mediated relaxation but not of the pressure-induced relaxation of the stomach indicates the existence of at least two separate neuronal pathways able to generate NO and bring about gastric accommodation of food or fluid.

Involvement of nitric oxide in the reflex relaxation of the stomach to accommodate food or fluid

The fundus of the guinea-pig stomach actively dilates in response to low increases in intragastric pressure. This physiological response, now called adaptive relaxation, accommodates the intake of liquid or food. It is independent of external innervation, resistant to ganglion blockade, but reflex in origin. The nerves involved are neither adrenergic nor cholinergic in nature. Non-adrenergic, non-cholinergic (NANC) nerves have now been recognized in many parts of the gastrointestinal tract and have recently been linked with release of nitric oxide (NO) on electrical stimulation. Here we show that adaptive relaxation in isolated stomach of the guinea pig is mediated by a NANC neurotransmitter substance indistinguishable from NO derived from L-arginine. This is substantiated by inhibition of adaptive relaxation by NG-monomethyl-L-arginine or N omega-nitro-L-arginine methyl ester, both inhibitors of NO synthesis, and by methylene blue, an inhibitor of soluble guanylate cyclase. There are two distinct neuronal pathways signalling NO-dependent adaptive relaxation, as evidenced by tetrodotoxin sensitivity. The first is a local reflex arc, the afferent fibres of which sense changes in intragastric pressure. The second is stimulated by an agonist for ganglionic nicotinic receptors. Thus, the functional significance of NO release from NANC nerves in the stomach is to bring about adaptive relaxation through a reflex response to increases in intragastric pressure.

Non-invasive assessment of arteriogenic impotence: a comparative study

This study was undertaken to determine the relative accuracy of computerised Doppler waveform analysis and colour coded duplex ultrasonography in the diagnosis of arteriogenic impotence. Twenty men with ostensibly normal penile haemodynamics were compared with 50 men whose impotence was considered due to compromised penile haemodynamics. In each patient the penile arterial inflow was assessed by both methods of investigation, which were performed at an interval of 2 weeks. The results demonstrated both techniques to be sensitive in detecting penile artery insufficiency but colour coded duplex ultrasonography was significantly more accurate.

Saline-induced artificial erection without papaverine: a potential source of error in diagnosing cavernosal venous leakage

The diagnosis of venous leakage as a cause of impotence, based on failure to induce an artificial erection by means of rapid saline infusion alone, may be invalid. Our recent experience with 2 men whose impotence was subsequently found to be psychogenic in nature suggests that saline erection cavernosometry should routinely incorporate the intracavernosal administration of papaverine, in order to avoid a falsely positive diagnosis of venous leakage.

A double-blind comparative trial of short-term orally administered enoxacin in the prevention of urinary infection after elective transurethral prostatectomy: a clinical and pharmacokinetic study

A double-blind randomized comparative study was done to investigate the efficacy of enoxacin in the prevention of urinary infection after elective transurethral prostatectomy, as well as its ability to penetrate the prostate. A total of 40 patients received 200 mg. enoxacin and 40 received a placebo, given orally the night before the operation, 2 to 4 hours preoperatively and every 12 hours postoperatively for 36 hours. Urine samples for bacterial culture were obtained within 1 week preoperatively, at operation and at 48 hours, 5 days, and 2 and 6 weeks postoperatively. Samples of the serum and prostate were taken at operation and assayed for enoxacin levels. Of the placebo patients 15 had a urinary infection postoperatively (38 per cent) compared to 3 enoxacin patients (8 per cent) (p less than 0.01). Enoxacin penetrated well into prostatic tissue; the mean levels in tissue and serum were 3.1 +/- 1.8 mg. per kg. (standard deviation) and 1.26 +/- 0.48 mg. per l., respectively, with a mean tissue-to-serum ratio of 2.53 +/- 1.8.

Development of a penile rigidity indicator and new concepts in the quantification of rigidity

A new non-invasive device has been developed for the continuous measurement of penile rigidity. We describe its design and performance in experimental and clinical studies, both of which have demonstrated its high degree of sensitivity, reliability and reproducibility. We also report two new concepts in quantifying penile rigidity.

Neurophysiological investigation of diabetic impotence. Are sacral response studies of value?

The role of electrophysiologically elicited sacral responses in the detection of the neurological component of diabetic impotence has been evaluated in a detailed study using properly defined diagnostic criteria. The results prove that these tests are not reliable indicators of neuropathy and their relevance in the routine investigation of diabetic impotence is of questionable value.

Penile corporeal fibrosis complicating papaverine self-injection therapy for erectile impotence

A case of loclaised penile corporeal fibrosis is described in a psychogenically impotent diabetic, following a short course of self-injection therapy with papaverine. The possible aetiology and implications of this complication are discussed together with the need to obtain informed written consent from patients undergoing this form of treatment.

Application of computerised penile arterial waveform analysis in the diagnosis of arteriogenic impotence. An initial study in potent and impotent men

A new method is described for evaluating arteriogenic impotence by means of noninvasive quantification of penile Doppler arterial waveforms using computerised analysis based on the Laplace Transform model. The haemodynamic changes occurring during a papaverine-induced erection in healthy potent volunteers have been recorded by this technique, which has also been shown to be capable of discriminating between a normal and an abnormal penile arterial supply in an initial study of potent and impotent men.

Preliminary report of a new concept in the pharmacological treatment of erectile impotence using an implantable drug delivery system

A new approach in the treatment of erectile impotence by means of pharmacologically induced erections using a totally implantable drug delivery system is described. This method allows administration of the appropriate drug at a site remote from the penis, thereby overcoming the pain and discomfort associated with direct intrapenile injection.

Fate of the testis following epididymitis: a clinical and ultrasound study

The progress of 33 men suffering from acute epididymitis, the majority of whom were treated as hospital inpatients, was prospectively monitored in order to determine the incidence of complications, and to assess the prognostic implications of clinical and scrotal ultrasound features found at initial presentation. Serious testicular complications resulting in frank infarction, suppurative necrosis and late atrophy developed in 39%. Three factors were shown to have significant discriminant value in predicting an adverse outcome: severe degree of inflammation with induration of the spermatic cord; the presence of a coexistent bacterial urinary infection; and a uniformly reduced testicular echo pattern on the affected side as visualized on ultrasound. A more aggressive approach in addition to medical measures appears to be indicated in these patients. The rationale of early surgical decompression by epididymotomy and spermatic fasciotomy is discussed. Scrotal ultrasound should be considered as a routine investigation in the management of epididymitis.

Localised intratesticular abscess complicating epididymo-orchitis: the use of scrotal ultrasonography in diagnosis and management

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Vasal urinary fistula with retrograde reflux of urine after vasectomy

We report a case of urinary fistula after scrotal vasectomy for recurrent epididymo-orchitis. The etiology of this rare complication is discussed and the literature is reviewed.

Population study of causes, treatment, and outcome of infertility

Specialist infertility practice was studied in a group of 708 couples within a population of residents of a single health district in England. They represented an annual incidence of 1.2 couples for every 1000 of the population. At least one in six couples needed specialist help at some time in their lives because of an average of infertility of 21/2 years, 71% of whom were trying for their first baby. Those attending gynaecology clinics made up 10% of new and 22% of all attendances. Failure of ovulation (amenorrhoea or oligomenorrhoea) occurred in 21% of cases and was successfully treated (two year conception rates of 96% and 78%). Tubal damage (14%) had a poor outlook (19%) despite surgery. Endometriosis accounted for infertility in 6%, although seldom because of tubal damage, cervical mucus defects or dysfunction in 3%, and coital failure in up to 6%. Sperm defects or dysfunction were the commonest defined cause of infertility (24%) and led to a poor chance of pregnancy (0-27%) without donor insemination. Obstructive azoospermia or primary spermatogenic failure was uncommon (2%) and hormonal causes of male infertility rare. Infertility was unexplained in 28% and the chance of pregnancy (overall 72%) was mainly determined by duration of infertility. In vitro fertilisation could benefit 80% of cases of tubal damage and 25% of unexplained infertility--that is, 18% of all cases, representing up to 216 new cases each year per million of the total population.

Scrotal ultrasound

Scrotal ultrasonography has been performed in 105 men with a variety of intrascrotal conditions. The range of pathology interpreted by this technique is presented and its diagnostic accuracy evaluated. The clinical application and usefulness of this noninvasive method of imaging scrotal contents is discussed.