Search PubMed⌕ Search

Biomedical subjects

H Hedlund

Publications and source records attributed to H Hedlund.

88 records · Page 5Linked to original sources
PubMed1985

Ejaculation and sexual function after endoscopic bladder neck incision.

Endoscopic incision of the bladder neck, performed to relieve outflow obstruction, was evaluated as regards effects on ejaculation and orgasm in 61 men (mean age 48 years) by analyses of seminal fluid and a questionnaire. Relief of obstruction was confirmed by post-operative normalisation of urinary flow. In 47 cases there was unchanged antegrade ejaculation, while reduced semen volume was reported by 11 men and retrograde ejaculation by only 3. The quality of orgasm and sexual satisfaction were not permanently changed by the operation. Post-operative analysis of seminal fluid was performed in 27 patients, with normal results in 26. In 16 men who provided specimens both before and after bladder neck incision, no consistent change was found in the semen. An incision completely splitting the bladder neck but not extending distal to the verumontanum will relieve outlet obstruction. Maintenance of antegrade ejaculation can be expected in most patients undergoing this operation.

Adult↗
PubMed1985

Effect of drugs interacting with adrenoreceptors and muscarinic receptors in the epididymal and prostatic parts of the human isolated vas deferens.

Electrical field stimulation of ring preparations of the epididymal (Ve) and prostatic (Vp) parts of the human isolated vas deferens produced contractions with similar frequency-dependence and appearance. The contractions of Ve, but not of Vp preparations were abolished by tetrodotoxin (10(-6)M). Noradrenaline (NA), phenylephrine, and methoxamine, but not clonidine induced repetitive, phasic contractions in both Ve and Vp preparations, and increased the amplitude of electrically induced responses. Clonidine concentration-dependently decreased electrically induced contractions in Ve preparations, but had no significant effects in Vp preparations. Phentolamine and prazosin abolished electrically induced contractions in Ve but not in Vp preparations. In Ve rings the contractions were increased by rauwolscine; no such effect was observed in Vp preparations. Isoprenaline, propranolol, acetylcholine and carbachol had no effects in the Ve or Vp preparations. Scopolamine and atropine reduced electrically induced responses. Clonidine decreased and rauwolscine increased the electrically induced release of 3H in both Ve and Vp preparations pre-loaded with 3H-NA. Phenylephrine, prazosin, isoprenaline, propranolol, carbachol and scopolamine had minor or no effects on the 3H release. Radioligand receptor binding experiments using 3H-prazosin and 3H-rauwolscine as ligands revealed similar densities of alpha 1- and alpha 2-adrenoreceptors in the human vas deferens. There seemed to be no differences in their distribution between the epididymal, middle and prostatic part of the organ. It is concluded that the neurotransmission in the human vas deferens is noradrenergic and mediated via alpha 1-adrenoreceptors. The prazosin and tetrodotoxin resistant part of the electrically induced contraction in Vp preparations may be caused by direct smooth muscle stimulation.

Adult↗
PubMed1985

Comparison of the responses to drugs acting on adrenoreceptors and muscarinic receptors in human isolated corpus cavernosum and cavernous artery.

The contractile and relaxant effects of drugs which interact with adreno- and muscarinic receptors were investigated in isolated tissue from the human corpus cavernosum urethrae (CC) and the cavernous artery (Acc). Isolated CC preparations were contracted in a concentration-dependent fashion by noradrenaline (NA), phenylephrine and clonidine in the mentioned order of potency. Prazosin was 300 times more active than rauwolscine in inhibiting NA-induced contractions. In segments of the isolated Acc, clonidine was more potent than NA and phenylephrine, and prazosin and rauwolscine were about equieffective in inhibiting NA-induced contractions. Prazosin was more effective than rauwolscine in CC strips, and rauwolscine more effective than prazosin in Acc segments in inhibiting the noradrenergically mediated part of electrically induced contractions. Isoprenaline, prenalterol and procaterol each relaxed NA-contracted CC preparations in a concentration-dependent way; this effect was blocked by propranolol. Isoprenaline had no relaxant action in Acc segments. Neither acetylcholine (ACh) nor carbachol produced contraction in CC and Acc preparations. ACh, but particularly carbachol, had potent relaxant effects in NA-contracted CC preparations. This effect of ACh and carbachol was blocked by scopolamine. Relaxant, but less potent effects of the muscarinic receptor agonists were found in the Acc segments. It is suggested that there are important differences between penile arteries and erectile tissue proper in the response to adrenoreceptor and muscarinic receptor active drugs. The contractile effect of NA seems to be mediated mainly by alpha 1-adrenoreceptors in the CC and by alpha 2-adrenoreceptors in the Acc. It cannot be excluded that muscarinic receptor-mediated relaxation of NA-contracted CC preparations can be of importance for penile tumescence and erection.

Acetylcholine↗
PubMed1985

Studies on the integrated extrinsic nervous control of rectal motility in the cat.

The effect of sympathetic nervous activity on rectal motility induced by pelvic nerve stimulation (PNS) was studied in anaesthetized cats. Division of the sympathetic lumbar colonic and hypogastric nerves or alpha-adrenoreceptor blockade, both of which reduced rectal tone, also reversed a predominantly relaxatory pelvic nerve response into a pure contraction. Contractions to pelvic nerve stimulation were reduced by simultaneous lumbar colonic nerve stimulation. This lumbar colonic nerve-induced inhibition was augmented by alpha-adrenoceptor blockade and abolished by beta-blockade. Close intra-arterial injection of a beta-adrenergic agonist reduced contractions to PNS, while an alpha-adrenergic agonist had no effect. Stimulation of the hypogastric nerves enhanced rectal contractions to simultaneous PNS. The apparent similarity with the arrangement of extrinsic nervous control of the internal anal sphincter suggests that the rectum is functionally involved in continence mechanisms.

Adrenergic alpha-Agonists↗
PubMed1985

Effects of some peptides on isolated human penile erectile tissue and cavernous artery.

Contractant and relaxant effects of four peptides known to occur in nerves innervating human penile vessels and erectile tissue, namely substance P (SP), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY) and somatostatin, were studied in isolated preparations from the corpus cavernosum (CC), corpus spongiosum (CS) and cavernous artery (Acc). In addition, the actions of another peptide, arginine vasopressin (AVP), were investigated. In erectile tissue proper, SP induced concentration-dependent contractions. No effect of this peptide was observed in Acc segments. CC and CS preparations contracted by noradrenaline (NA) were relaxed by 30-40%; the effect in NA-contracted Acc preparations was inconsistent. AVP had a potent contractant effect in preparations from all the tissues studied, the effect being most conspicuous in CS strips. VIP was without contractant actions in any of the preparations. NA-contracted preparations were relaxed by VIP, and electrically induced contractions inhibited. The inhibitory effect was particularly marked in electrically stimulated CC and CS preparations. NPY had no effects; somatostatin contracted Acc segments, and in high concentrations CC and CS strips. It is concluded that among the peptides studied only VIP has effects compatible with a role as a neurotransmitter in penile erection.

Aged↗
PubMed1985

On the transmission of sacral parasympathetic nervous influence on distal colonic and rectal motility in the cat.

Experiments were performed on cats anaesthetized with chloralose and treated with adrenoceptor blocking agents. Distal colonic and rectal motility were selectively recorded by a volumetric method. The effects of muscarinic and ganglionic nicotine receptor blockade on motor responses induced by graded efferent electrical pelvic nerve stimulation (PNS) were studied. Stimulation at low current strength evoked contractions in both the colon and the rectum, which were sensitive to atropine and to hexamethonium. High intensity stimulation elicited distal colonic contractions resistant to both atropine and hexamethonium. Similar excitatory responses to high strength PNS were also observed in the rectum, though not in all experiments. Stimulation at intermediate intensities evoked distal colonic and rectal relaxations which were resistant to atropine but blocked by hexamethonium. The results indicate that PNS influences colonic and rectal motility by activation of at least three discrete non-adrenergic nervous pathways: (1) low-threshold excitatory fibres involving nicotinic and muscarinic transmission, (2) high-threshold excitatory fibres with a non-muscarinic, non-nicotinic transmission mechanism, (3) inhibitory fibres with an intermediate stimulus intensity threshold, exerting their effect by a non-muscarinic mechanism involving a nicotinic step.

Animals↗
PubMed1984

Dynamics of a continent caecal reservoir for urinary diversion.

Motor activity of the caecal reservoir for urine, and of the intussuscepted nipple valve in the ileal outlet, was studied in seven continent and two incontinent patients by means of a catheter equipped with two microtransducers. The basal pressure was low in the reservoir even at large-volume filling. In the continent patients the basal pressure was always higher in the ileal outlet than in the reservoir. No high-pressure zone was present in the outlet in the incontinent patients. Intermittent pressure waves occurred in the reservoir, and they increased in frequency, duration and amplitude with increasing filling. Pressure waves with higher amplitude arose simultaneously in the outlet. Increasing time from construction of the reservoir was accompanied by decreasing amplitude of the pressure waves, indicating adaptation towards the larger functional capacity of the reservoir. The recorded dynamics seemed to reflect the functional state of the reservoir.

Adult↗
PubMed1984

Pre- and postjunctional adreno- and muscarinic receptor functions in the isolated human corpus spongiosum urethrae.

In isolated tissue from the human corpus spongiosum urethrae (CS) the effects of adrenoreceptor and muscarinic receptor active drugs on release of 3H-noradrenaline (NA) from noradrenergic nerves and on isometric tension were investigated. The electrically induced release of 3H was reduced by clonidine (alpha 2-adrenoreceptor agonist), increased by rauwolscine (alpha 2-adrenoreceptor antagonist), and little affected by phenylephrine (alpha 1-adrenoreceptor agonist) and prazosin (alpha 1-adrenoreceptor antagonist). Isoprenaline (beta 1- and beta 2-adrenoreceptor agonist) and procaterol (beta 2-adrenoreceptor agonist) increased the release, propranolol (beta 1- and beta 2-adrenoreceptor antagonist) reduced it, and prenalterol (beta 1-adrenoreceptor agonist) and atenolol (beta 1-adrenoreceptor antagonist) had no effect. Carbachol (muscarinic receptor agonist) decreased and scopolamine (muscarinic receptor antagonist) increased stimulation-induced efflux of 3H. NA, phenylephrine and clonidine contracted isolated CS preparations, clonidine being less potent and having less intrinsic activity than phenylephrine. Prazosin was more effective than rauwolscine for inhibition of NA-induced contractions, and prazosin, but not rauwolscine, abolished electrically induced contractions. Isoprenaline and procaterol, but not prenalterol, relaxed NA-contracted preparations. These relaxations could be blocked by propranolol but not by atenolol. Acetylcholine and carbachol relaxed NA-contracted preparations but had no contractant effect on any of the preparations tested. The results suggest that prejunctionally in the human CS, the alpha-adrenoreceptors are of alpha 2-type and the beta-adrenoreceptors of beta 2-type. Postjunctionally, the main alpha-adrenoreceptor function seems to be of alpha 1-type and the beta-adrenoreceptor function of beta 2-type. Stimulation of muscarinic receptors may inhibit the effects of NA both by decreasing its release from noradrenergic nerves and by counteracting its postjunctional effects.

Adrenergic alpha-Agonists↗
PubMed1984

Efferent sympathetic nervous control of rectal motility in the cat.

The sympathetic nervous control of rectal motility was studied in anesthetized cats. Division of the sympathetic nerves, i.e. the hypogastric nerves and the lumbar colonic nerves and alpha-adrenergic blockade reduced rectal tone indicating that these nerves are tonically active. Efferent electrical stimulation of the nerves at high intensities caused an immediate and sustained contraction which was inhibited after phentolamine but unaffected by hexamethonium suggesting a direct alpha-adrenergic effect on the rectal smooth muscle. However when prevailing rectal tone was high beta-adrenergic inhibitory responses unaffected by hexamethonium were observed. In addition the hypogastric nerves seem to convey cholinergic excitatory fibres to the rectum. The results imply that the sympathetic nerves are integrated in the nervous regulation of rectal motility in a fashion similar to the nervous control of the internal anal sphincter.

Animals↗
PubMed1983

Effects of prazosin in patients with benign prostatic obstruction.

Prazosin, a selective alpha-1-adrenoceptor blocker, was used in a double-blind crossover study in 20 men with benign prostatic obstruction. Maximum and average flow rates increased, and residual volume and obstructive symptoms were reduced. Voiding pressure parameters, bladder capacity and irritative symptoms did not change significantly. No side effects were noted. We conclude that prazosin seems to be an effective therapeutic alternative in patients with benign prostatic obstruction.

Aged↗
PubMed1983

The effects of 5-hydroxytryptamine on large intestinal motility and blood flow in the cat.

The effects of 5-HT on proximal colonic and rectal motility and total colonic blood flow were studied in anaesthetized cats and compared with those evoked by pelvic nerve stimulation. Vasodilator responses, consistently elicited by low doses (5-10 micrograms/min close i.a.) and intermediate doses (10-50 micrograms/min) of 5-HT were invariably abolished by hexamethonium indicating a nerve mediated response. Simultaneously to the vasodilator response both cholinergic and non-cholinergic hexamethonium sensitive non-adrenergic motility responses were evoked in the proximal colon. Furthermore non-cholinergic, non-adrenergic inhibitory neurons were excited. In the rectum excitation of such inhibitory neurons was the most consistent finding. The mechanisms behind the nerve mediated vascular and motility responses seem to differ as only the vascular effects were blocked by dihydroergotamine. The nerve mediated responses were in many respects similar to those evoked by pelvic nerve stimulation indicating that 5-HT exerts its effects on the same instrinsic neurons as the pelvic nerves. At intermediate and high doses (50-100 micrograms/min) the effects exerted on the instrinsic reflex arcs were modulated by direct effects on the smooth muscle.

Animals↗
PubMed1983

Functional results after subtotal colectomy and caecorectal anastomosis.

Subtotal colectomy, preserving the ileocaecal valve and caecum, and caecoproctostomy has been recommended by some authors in the past and hypothetically it is a good a priori argument on the grounds of function for its use. The procedure has been employed in nine patients on different indications and the functional results assessed. When employed for treatment of chronic constipation or diverticular disease of the colon the functional results were poor. If the operation should be used at all it should probably be restricted to patients with an otherwise normal colorectal function. Even when employed on these indications, bowel habits differ little from those experienced by patients with a conventional ileorectal anastomosis.

Adult↗
PubMed1982

Autosuture of low colorectal anastomosis.

The safety of low colorectal anastomosis constructed with autosuture technique (U.S. EEA-stapling device, USSC) and the functional results were assessed in consecutive series of patients operated upon for rectal carcinoma. The operative procedure was greatly facilitated and certainly, many of the patients would otherwise have been subjected to abdominoperineal resection with permanent colostomy. Clinical leaks were observed in 4 of the 25 patients (16%) and another 4 patients were shown to have subclinical leaks, as demonstrated by endoscopy and/or X-ray. The total incidence of leaks was therefore 32% (8/25). Even when constructed with the autosuture technique a low anastomosis should probably be protected by a proximal enterostomy. There was a general tendency to anastomic narrowing during the initial period but in most patients stenosis disappeared with time after closure of the enterostomy. Frequent endoscopic examinations and dilatation of the anastomosis during the early postoperative period may be advantageous. The immediate functional results were unsatisfactory with increased frequency and varying grades of incontinence. Although these disturbances improved with time the results at six months after surgery were still not satisfactory and for confidence many patients wore a pad.

Aged↗
PubMed1981

Effects of prazosin on isolated human urethra and in patients with lower motor neurons lesions.

In isolated human urethra, prazosin competitively inhibited contractions induced by noradrenaline, but had no effect on contractions elicited by potassium (127 mM), suggesting an action solely on alpha-adrenoceptors. Seven patients with lower motor neuron lesions and micturition disturbances were treated with 2 mg of prazosin twice daily. Five were investigated by simultaneous urethrocystometry before and during treatment. Prazosin reduced the intraurethral pressure, the intravesical pressure during bladder filling, and autonomous bladder waves. Voiding and incontinence improved in five patients. In one, voiding was facilitated, but continence deteriorated, and in one, no clinical effects were observed. In all patients, residual urine decreased. There were no side effects, except one case of nasal congestion. It is concluded that prazosin effectively reduces alpha-adrenoceptor mediated hyperactivity in the smooth muscle of the lower urinary tract, and that it may be an effective treatment of micturition disturbances in patients with lower motor neuron lesions.

Adolescent↗