Direct evidence for the involvement of vasoactive intestinal polypeptide in the motor response of the human isolated ileum to capsaicin

Capsaicin (1 microM) produced complex motor responses in longitudinal and circular muscle strips from the human isolated small intestine (jejunum and ileum). In the longitudinal muscle, inhibition of the nerve-mediated contractions (electrical field stimulation) was the dominant response, while capsaicin had a weak and inconsistent effect on tone and spontaneous activity. In contrast, relaxation and decreased spontaneous activity were the responses of the circular muscle to capsaicin. These effects of capsaicin were not reproduced by a second application of capsaicin, indicating desensitization, a feature of the specific action of this drug on sensory nerves. All the effects of capsaicin in the longitudinal and circular muscle were closely mimicked by exogenous vasoactive intestinal polypeptide (VIP). Further, the inhibitory motor effect of capsaicin in both muscle layers was blocked by an anti VIP serum. In the longitudinal muscle, VIP, like capsaicin, inhibited the electrically evoked nerve-mediated contractions but not the tetrodotoxin-resistant myogenic contractions, suggesting a prejunctional site of action. The inhibitory effect of both capsaicin and VIP in the circular muscle was tetrodotoxin-resistant suggesting direct inhibition of muscle cells. Capsaicin (1 microM) evoked a tetrodotoxin-resistant release of VIP-like immunoreactivity from the human small intestine. On high pressure liquid chromatography, a major peak of the immunoreactive material released by capsaicin co-eluted with authentic VIP and a minor, unidentified peak eluted shortly afterward. We conclude that authentic VIP is involved in the local motor response to capsaicin in the human small intestine. These findings raise the possibility that VIP might be present in sensory nerves of the human gut from which it is released by capsaicin.

Human isolated ileum: motor responses of the circular muscle to electrical field stimulation and exogenous neuropeptides

(1) Circularly-oriented muscle strips from the human ileum responded to electrical field stimulation (1-50 Hz) with frequency-related primary relaxation at low frequency and primary contractions at high frequencies of stimulation. Both responses were abolished or markedly reduced by tetrodotoxin (1 microM). (2) Atropine (3 microM) or omega conotoxin (0.1 microM) reduced but dit not abolish contraction to electrical field stimulation and enhanced the relaxation. Omega conotoxin (0.1 microM) did not affect carbachol-induced contraction nor isoprenaline-induced relaxation. (3) Neurokinin A and substance P (1 nM-1 microM) produced a concentration-dependent contraction. The NK-1 receptor selective agonist, [Pro9]SP sulfone and the NK-2 receptor selective agonist [beta Ala8]NKA(4-10) produced a contraction superimposable to that of substance P and neurokinin A, respectively. On the other hand, [MePhe7]-neurokinin B, an NK-3 receptor selective agonist was ineffective up to 1 microM. The response to substance P or neurokinin A was unaffected by atropine (3 microM). (4) Galanin, up to 0.1 microM, produced a weak and inconsistent contraction. (5) Vasoactive intestinal polypeptide (10 nM-1 microM) produced a concentration-dependent relaxation while human alpha calcitonin gene-related peptide exerted a weak and inconsistent relaxant effect. (6) These findings indicate that both cholinergic excitatory and non-cholinergic inhibitory nerves affect the motility of the circular muscle of the human small intestine. Transmitter release from excitatory nerves seems largely mediated by activation of omega conotoxin-sensitive (N-type) calcium channels. Tachykinins exert a potent contractile effect, independently of cholinergic nerves, via NK-1 and NK-2 receptors.

Motor response of the human isolated colon to capsaicin and its relationship to release of vasoactive intestinal polypeptide

The aim of this study was to obtain indirect evidence of the presence of capsaicin-sensitive afferents in the human colon by studying the motor response to capsaicin of longitudinal strips from the human isolated taenia coli in parallel to the ability of capsaicin or KCl to induce peptide release from the human superfused colon. Capsaicin (1 microM) evoked a relaxation of the taenia, approaching 60-80% of the response to isoprenaline. Tachykinins evoked contractions of the taenia, while calcitonin gene-related peptide induced a relaxation. Neither tachyphylaxis to calcitonin gene-related peptide nor preincubation with an anti-calcitonin gene-related peptide serum did block the response to capsaicin which was also unaffected by tetrodotoxin, apamin, naloxone or an anti-galanin serum. Vasoactive intestinal polypeptide produced a concentration-dependent tetrodotoxin-resistant relaxation which was shifted rightward in the presence of anti-vasoactive intestinal polypeptide serum. The anti-vasoactive intestinal polypeptide serum reduced the response to capsaicin and application of capsaicin prevented the ability of anti-vasoactive intestinal polypeptide serum to block exogenous vasoactive intestinal polypeptide. Capsaicin (1 microM) evoked a significant release of vasoactive intestinal polypeptide-like immunoreactivity from the superfused muscle but not mucosa of the human colon. A significant vasoactive intestinal polypeptide-like immunoreactivity release was also observed in response to KCl (80 mM). KCl but not capsaicin evoked a significant release of neurokinin A-like immunoreactivity from colonic muscle and mucosa. No significant release of either substance P-, neuropeptide Y-, galanin- or calcitonin gene-related peptide-like immunoreactivity was detected in response to capsaicin or KCl although detectable levels of each peptide were evident in tissue extracts.(ABSTRACT TRUNCATED AT 250 WORDS)

Motor response of the human isolated small intestine and urinary bladder to porcine neuromedin U-8

1. Porcine neuromedin U-8 produced a concentration (0.3 nM-1 microM)-dependent contraction of the longitudinal muscle of the human isolated ileum, which was unaffected by either atropine (1 microM) or tetrodotoxin (1 microM). 2. By contrast, neuromedin U-8 had only a weak effect on the circular muscle of the human isolated ileum. 3. Neuromedin U-8 also produced a concentration-dependent contraction of mucosa-free muscle strips from the dome of the human isolated urinary bladder, its action being unaffected by either atropine or tetrodotoxin. 4. These findings indicate that neuromedin U-8 exerts a direct contractile effect on smooth muscle of the human intestinal and urinary tract.

Contractile responses of the human urinary bladder, renal pelvis and renal artery to endothelins and sarafotoxin S6b

1. Endothelin-1 (ET-1), endothelin-3 (ET-3) and sarafotoxin S6b (SRFTX) produced a concentration-dependent tonic contraction of the human isolated urinary bladder, renal pelvis and renal artery with threshold at nM concentration. 2. In the bladder, the following order of potency was found: ET-1 greater than SRFTX greater than ET-3. In the renal pelvis, all peptides displayed similar affinity but, at high concentrations the maximal response was highest for SRFTX followed by ET-1 and ET-3. In the renal artery ET-1 and SRFTX were about equipotent and equieffective while ET-3 produced only a slight and inconsistent (2 out of 5 cases) vasoconstrictor response. 3. As shown previously for the human bladder muscle, the response to ET-1 in the renal pelvis was nifedipine (1 microM)-resistant while a consistent fraction of the response was blocked by nifedipine in the human renal artery. 4. These findings indicate that peptides of the endothelin family exert a potent contractile effect on various human smooth muscles. Participation of dihydropyridine- and voltage-sensitive calcium channels in the contractile response produced by these peptides may vary from one organ to another.

Multiple sources of calcium for contraction of the human urinary bladder muscle

1. KCl, carbachol, neurokinin A and endothelin produced concentration-dependent contractions of mucosa-free muscle strips from the dome of the human urinary bladder. The maximal response to carbachol or neurokinin A exceeded that to KCl, while the maximal response to endothelin approached that to KCl. 2. Nifedipine (1 microM) abolished the response to KCl, reduced the response to carbachol or neurokinin A but had no effect on the response to endothelin. Bay K 8644 (1 microM) markedly potentiated the response to KCl but had little or no effect on the response produced by the other stimulants. 3. Superfusion of the strips with a nominally calcium (Ca)-free medium containing EDTA (1 mM) for 30 min markedly reduced the response to carbachol, neurokinin A and endothelin, although a small response was still evident at high concentrations. Likewise, after a prolonged (60 min) superfusion of the strips with a high K (80 mM) Ca-free medium plus EDTA (1 mM) these three agonists still produced a small contractile response. 4. The nifedipine (1 microM) resistant response to carbachol, neurokinin A or endothelin was markedly depressed by LaCl3 (1 mM). In contrast, the nifedipine-(1 microM) resistant response to carbachol was not modified by NiCl2 (0.1 mM) or omega-conotoxin (0.1 microM). 5. Caffeine produced divergent effects depending upon the temperature of incubation: a relaxation at 37 degrees C and a concentration-dependent (2.5-20 mM) contraction at 25 degrees C. The latter was markedly inhibited by procaine (3 mM) but unaffected by nifedipine (1 microM). 6. After a prolonged (60 min) superfusion with a high K, Ca-free medium containing EDTA the response to carbachol (100 microM) was abolished by previous exposure to procaine (3 mM). Conversely, the response to endothelin (1 microM) was unaffected by procaine. The response to endothelin in these experimental conditions was also resistant to LaCl3 (1 mM). 7. These findings indicate that multiple sources of Ca are mobilized for contraction of the human bladder muscle by different stimulants. Dihydropyridine- and voltage-sensitive Ca channels provide the major if not the sole source of Ca for the response to KCl, play some role in the response to muscarinic (carbachol) or NK-2 tachykinin receptor stimulation but are not involved in the response to endothelin. Carbachol, neurokinin A and endothelin all mobilize a Ca pool (either extracellular or located at membrane level) which is LaCl3-sensitive but nifedipine-resistant. Neither T- nor N-type channels appear to be involved in the response to carbachol. In addition, these agents mobilize a tightly bound Ca pool independently from membrane depolarization. This latter pool is probably a procaine-sensitive intracellular source of activator Ca mobilized by caffeine and carbachol. The failure of procaine to prevent the response to endothelin in high K, Ca-free medium raises the possibility that this peptide mobilizes an intracellular source of activator Ca, distinct from the caffeine- and carbachol-sensitive pool.

Cystometric evidence that capsaicin-sensitive nerves modulate the afferent branch of micturition reflex in humans

Intravesical instillation of capsaicin (0.1 to 10 microM) in six patients (five with hypersensitive disorders of the lower urinary tract, one with benign prostatic hyperplasia) produced a concentration-related reduction of the first desire to void, bladder capacity and pressure threshold for micturition. At a threshold concentration of one microM, capsaicin also produced a warm to burning sensation referred to the suprapubic area during the collecting phase and to the urethra during micturition. All the patients with hypersensitive disorders of the lower urinary tract reported disappearance or marked attenuation of their symptoms for a few days after capsaicin application. In three other patients with hypersensitive disorders of the lower urinary tract, intravesical instillation of capsaicin's vehicle (0.1% ethanol in saline) did not produce significant cystometric changes nor modify the symptomatology. These observations provide the first indication that capsaicin-sensitive structures (nerves?) may be present in the human urinary bladder as they have been shown to occur in various other species.

Release of VIP- but not CGRP-like immunoreactivity by capsaicin from the human isolated small intestine

Exposure to capsaicin (1 microM) produced a prompt and sustained release of vasoactive intestinal polypeptide-like immunoreactivity (VIP-LI) from mucosa-free strips of human small intestine (jejunum and ileum). A second application of capsaicin, 60 min later, had no effect indicating complete desensitization, a specific feature of the action of capsaicin on sensory nerves. By contrast no release of calcitonin gene-related peptide (CGRP)-LI was produced upon the first or second application of capsaicin.

Human isolated small intestine: motor responses of the longitudinal muscle to field stimulation and exogenous neuropeptides

(1) Longitudinal muscle strips from the human small intestine (jejunum/ileum) responded to electrical field stimulation (1-50 Hz) with frequency-related primary contractions which were largely atropine- (3 microM) sensitive. When the tone was raised by addition of galanin (0.3-1 microM), prostaglandin (PG) E2 (1-10 microM) or neurokinin A (NKA, 0.1 microM), a frequency-related relaxation was evident which was potentiated by atropine. All the responses to field stimulation were abolished by tetrodotoxin (1 microM), thus indicating their neural origin. (2) The atropine-sensitive primary contraction to field stimulation was virtually abolished by omega conotoxin fraction GVIA (CTX, 0.1-0.3 microM) while the relaxations were CTX-resistant. The field stimulation-induced relaxations, which were observed in the presence of atropine and guanethidine (3 microM), were also unaffected by apamin (0.1 microM). (3) NKA and substance P (SP) produced a concentration- (1 nM-1 microM for both peptides) related contraction, NKA being about 53 times more potent than SP. [Pro9]SP sulphone and [MePhe7]-NKB, selective agonists of the NK-1 and NK-3 receptor, respectively, were barely effective. On the other hand, [beta Ala8]NKA(4-10), a selective NK-2 receptor agonist, had a potent contractile activity, similar to that of NKA. (4) Galanin (1 nM-1 microM) produced an atropine- and tetrodotoxin-resistant concentration-related contraction of longitudinal muscle of human isolated small intestine. The response to galanin did not show any sign of fading and was particularly suitable to study the evoked relaxations.(ABSTRACT TRUNCATED AT 250 WORDS)

Potent contractile activity of endothelin on the human isolated urinary bladder

Endothelin (1 nM-0.3 microM) produced a concentration-related contraction of mucosa-free muscle strips excised from the dome of the human urinary bladder. The response to endothelin was unaffected by either atropine (1 microM) or nifedipine (1 microM) at concentrations that abolished the response to carbachol and KCl, respectively. These findings indicate that mechanisms other than activation of dihydropyridine- and voltage-sensitive calcium channels may be involved in the action of endothelin on smooth muscles.

Further studies on the motor response of the human isolated urinary bladder to tachykinins, capsaicin and electrical field stimulation

1. Muscle strips from the dome of the human urinary bladder responded to field stimulation with contractions which were atropine- (3 microM) and tetrodotoxin- (1 microM) sensitive. These contractions were sensitive to omega conotoxin (CTX, 0.1 microM). The atropine- and tetrodotoxin-resistant contractions produced by field stimulation were totally unaffected by CTX. 2. DMPP (30-100 microM), a nicotinic agonist, produced transient bladder contractions which were hexamethonium- and atropine-sensitive. 3. Tachykinins produced a contraction of the human bladder. Among several synthetic tachykinin analogs only those having activity at the NK-2 receptor produced a consistent contractile response. 4. Either capsaicin (1 microM) or calcitonin gene-related peptide (10 nM-0.1 microM) had no motor effect. At 10 microM, capsaicin exerted a depressant effect on nerve-mediated contractions but this effect did not exhibit desensitization. 5. These findings provide evidence that NK-2 receptors are the main if not the sole mediators of the contractile response of the muscle from the dome of the human isolated bladder to tachykinins. 6. No evidence was found for a tachykininergic component in the excitatory response to field stimulation nor for motor responses mediated by capsaicin-sensitive nerves. 7. CTX-sensitive calcium channels are probably present on cholinergic nerve terminals in the human bladder muscle.

Revascularization of the right ischemic kidney by gastroduodenal artery

Hepatorenal bypass can successfully accomplish revascularization of the right renal artery when the aorta or the iliac vessels cannot be used for a standard renal bypass or renal autotransplantation. The use of the hepatic circulation can be increased by the gastroduodenal to renal artery bypass procedure. Herein we report a clinical case of severe hypertension in a patient with a solitary functional kidney and an extensive atheromatous alteration of the aortoiliac segment. It has been corrected by means of a gastroduodenal end-to-side renal saphenous vein bypass graft.

Conservative surgical treatment of renal cell carcinoma: clinical experience and reappraisal of indications

During a 14-year period 36 patients who presented with renal cell carcinoma underwent conservative surgical treatment. The patients were divided into 3 groups according to treatment indications and condition of the contralateral kidney: group 1 included patients with a solitary kidney or bilateral tumors, group 2 patients had a damaged contralateral kidney and group 3 patients were without abnormalities of the contralateral kidney. Cumulative 6-year survival rates were 58 per cent for group 1, and 90 per cent for groups 2 and 3 combined. The over-all cumulative 6-year survival rate was 74 per cent. Based on these data extension of the indication for conservative surgical treatment seems to be justified in patients who present with low stage tumors and partial or potential damage to the contralateral organ.

Relaxation of isolated corpus cavernosum induced by smooth-muscle relaxant drugs. A comparative study

Intracavernous injection of vasoactive substances are used in the treatment and investigation of impotence. We studied the effects induced by some pharmacological agents on strips of human erectile tissue. Specimens of corpus cavernosum were obtained from 16 men undergoing cystectomy or penectomy for bladder or penile malignancy. Strip preparations were mounted in thermostically controlled baths containing Krebs solution. Pharmacologic effects were monitored by means of an isotonic transducer. Papaverine was shown to be the substance able to cause the biggest relaxation effect. The authors compared the action of other drugs having a relaxant effect, studied the antagonist effects of epinephrine and dopamine on the pharmacologically relaxed preparations, and stressed that the relaxation of the erectile tissue has a determinant role in the appearance and maintenance of erection.

Specific motor effects of capsaicin on human jejunum

Capsaicin (1 microM) produced a biphasic effect on the motility of longitudinal muscle strips from human jejunum e.g. an initial inhibitory effect on nerve-mediated contractions followed by a delayed increase in motility. Neither effect was observed upon a second application of the drug, indicating desensitization, a proposed marker of the action of capsaicin on sensory nerves. Both substance P and neurokinin A produced a contraction of isolated human jejunum, while calcitonin gene-related peptide had a small and inconsistent inhibitory effect.

Contractile response of the human isolated urinary bladder to neurokinins: involvement of NK-2 receptors

The contractile response to substance P (SP), neurokinin A (NKA) and arginin-neurokinin B (Arg-NKB) (a water soluble analogue of NKB) was investigated in detrusor muscle strips from the dome of the urinary bladder obtained from patients undergoing total cystectomy for carcinoma of the bladder base. Spontaneous activity and response to nerve stimulation indicated that the material used in this study has characteristics similar to those described for 'normal' human detrusor muscle. All neurokinins induced a concentration-related contraction with sensitivity at nM concentrations and the following rank order of potency: NKA (90) greater than Arg-NKB (22) greater than SP (1). These findings indicate the involvement of NK-2 receptors in the contractile response of human detrusor muscle to neurokinins.

Biological, diagnostic and therapeutic aspects of a case of renal cell carcinoma occurring with bladder and contralateral adrenal metastasis

We report a case of renal cell carcinoma occurring with bladder and contralateral adrenal metastasis discovered preoperatively with computerized tomography. Surgical treatment consisted of radical nephrectomy, with preservation of the ipsilateral adrenal gland, contralateral adrenalectomy, and transvesical resection of the bladder neoplasm. The hypothesis for the mechanism(s) of spread and treatment modalities are discussed.

Galanin: a potent modulator of excitatory neurotransmission in the human urinary bladder

Galanin (GAL) produced a concentration (0.3-100 nM)-related inhibition of the atropine-sensitive component of the contractions induced by field stimulation of detrusor strips from the dome of the human urinary bladder. GAL had an ED50 of 2 nM for the inhibition. The effect of GAL was prevented by atropine (1 microM) and was not seen when the strips were stimulated with a cholinomimetic or KCl. These data suggest a possible neuromodulator role of GAL in the human urinary bladder.

Caval extension of renal cell carcinoma. Results of surgical treatment

Twenty-eight patients with renal cell carcinoma extending to the vena cava underwent surgical treatment consisting of radical nephrectomy and removal of tumor thrombus, which was at the level of the renal veins in 23 cases, the hepatic veins in 4, and extending above the diaphragm in 1 case. In 7 patients lymph nodes were invaded, and 8 had both positive nodes and extrarenal tumor diffusion discovered at surgery. The mean survival was 41.7 months for patients with only venous extension of the tumor, 16 months for patients with positive nodes, and 10.2 months for those with both nodal and extrarenal tumor diffusion.

Simultaneous bilateral adrenal involvement by renal cell carcinoma: experience with 3 cases

We report 3 cases of renal cell carcinoma and synchronous bilateral adrenal metastases discovered preoperatively with computerized tomography and other imaging techniques. Surgical treatment consisted of radical nephrectomy through a transperitoneal approach, with adjunctive lower polar resection in a patient with bilateral renal tumors, and contralateral adrenalectomy. Subsequent steroid treatment was given.

Removal of renal cell carcinoma extending to the supradiaphragmatic vena cava with the aid of cardiopulmonary bypass

A woman with renal cell carcinoma confined within Gerota's fascia but extending to the supradiaphragmatic vena cava was successfully treated with the aid of cardiopulmonary bypass. The approach was a subcostal chevron incision coupled with a midline sternotomy. The rationale and indications for aggressive surgery of renal cell carcinoma with massive caval extension are discussed.

Intracavernous therapy in impotence after pelvic trauma. A preliminary study

Pelvic trauma, especially when complicated by a posterior urethral disruption, may cause impotence in 50% of patients. The treatment of this kind of impotence has always been troublesome for the urologist. In fact penile prostheses or the revascularization procedures have sometimes been failures. We present a series of 6 patients with impotence after pelvic trauma managed by intracavernous injection of papaverine and we describe here the preliminary results obtained.