Symptomatic cholecystolithiasis after laparoscopic cholecystectomy.

A 45-year-old woman was admitted to our hospital complaining of upper abdominal pain. Seven months earlier a laparoscopic cholecystectomy had been carried out and a solitary gallstone removed together with the gallbladder. The patient now suffered from pain of the same character but lower intensity compared to the situation before the operation. At admission there were no abnormal laboratory findings, especially no signs of infection or cholestasis. Ultrasound revealed a stone in a gallbladder-like structure in the right epigastric region. ERCP revealed an inconspicuous cystic duct stump and no pathological findings in the extra- and intrahepatic bile ducts. MRCP and CT showed a cyst-like structure in the gallbladder region containing a concrement. The patient was transferred to the Department of Surgery for exploratory laparotomy, and a residual gallbladder with an infundibular gallstone was removed. The recurrent upper abdominal pain was obviously caused by a gallstone redeveloped after incomplete laparoscopic gallbladder resection. Retrospectively it could not be discerned whether a doubled or a septated gallbladder was the reason for the initial incomplete resection.

[Recurrent sanguineous and mucous diarrhea and spasms in a 46-year-old woman--manifestation of endometriosis in the colon sigmoideum]. / Rezidivierende schleimig-blutige Diarrhöen und Tenesmen bei einer 46-jährigen Frau - Manifestation einer Endometriose im Colon sigmoideum.

Intestinal endometriosis is the most frequent extragenital manifestation of this disease. Sometimes patients even present with acute bowel obstruction. We report on a 46-year-old woman complaining about recurrent sanguineous and mucous diarrhea and spasms for several years. Colonoscopy showed a stenosis in the sigmoid colon without macroscopically visible alterations of the mucosa. Computertomography, ultrasound and barium contrast enema did not provide us with further information about the origin of the stenosis. Biopsies out of the mucosa at the stenosis showed typical endometriosis tissue. After starting a conservative therapy with GnRH-agonist gosereline the patient became completely free of symptoms. The coincidence of endometriosis and M. Crohn has to be taken into consideration. Therapy planning should include a close co-operation with gynaecologists and surgeons to transfer the patient to surgical intervention when needed.

Gallstones, the choledochoduodenal junction and initiation of acute pancreatitis: are two stones the culprits rather than one stone?

Reflux of biliary secretions into the pancreatic duct following gallstone obstruction of the common biliary pancreatic ampulla has been implicated as a cause of acute pancreatitis. However, the pancreatic duct pressure is higher than the biliary pressure and, therefore, the simple obstruction of the choledochoduodenal junction by one gallstone does not result in biliary pancreatic reflux. We propose a mechanism whereby simultaneous migration and sequential impaction above and below the common biliary pancreatic ampulla of two gallstones allows for the creation of a toxic bile-pancreatic juice mixture in the common bile duct, subsequent reversal of the pressure gradient and reflux of the toxic secretions into the pancreatic duct.

Relaxant effect of xenin on rat ileum is mediated by apamin-sensitive neurotensin-type receptors.

The action of xenin, a novel 25-residue peptide of the neurotensin (NT)/xenopsin family, was investigated in isolated rat ileal muscle strips and in dispersed longitudinal smooth muscle cells of rat small intestine in vitro. Xenin relaxes KCl-precontracted ileal strips dose dependently (1 nM-3 microM). The order of potency of the investigated peptides was as follows: xenopsin = NT = xenin > neuromedin N. Kinetensin was inactive. Tetrodotoxin, hexamethonium, tetraethylammonium, 4-aminopyridine, and NG-nitro-L-arginine did not influence the relaxant effects of xenin or NT, whereas the K+ channel blocker apamin nearly abolished their effects. Desensitization against one of the peptides or blockade of NT receptors by SR-48692 prevented the effect of xenin and NT. Structure-activity experiments revealed that the COOH-terminal part of the molecules of xenin and NT is essential for biological activity. Experiments with isolated dispersed smooth muscle cells and binding studies on intestinal smooth muscle cell membranes confirmed and extended the results obtained with muscle strips. In conclusion, xenin relaxes rat ileal smooth muscle via a muscular NT-type apamin-sensitive receptor.

Inhibitory transmission in guinea pig stomach mediated by distinct receptors for pituitary adenylate cyclase-activating peptide.

Previous studies have shown that inhibitory transmission in guinea pig stomach involves an interplay between vasoactive intestinal peptide (VIP) and nitric oxide (NO). The present study examined the contribution of pituitary adenylate cyclase-activating peptide (PACAP), a homologous peptide present in gastric and intestinal myenteric neurons. VIP, PACAP-27 and PACAP-38 induced concentration-dependent relaxation that was partly inhibited by the antagonists VIP10-28 and PACAP6-38 and the NO synthase inhibitor NG-nitro-L-arginine (L-NNA). Only relaxation induced by PACAP-27 and PACAP-38 was partly inhibited by apamin. Electrical field stimulation (0.25-16 Hz) induced frequency-dependent relaxation and PACAP release (maximum of 35.7 fmol/100 mg-min or 7-fold above basal levels). Electrical field stimulation-induced relaxation was partly inhibited by a combination of selective monoclonal antibodies to PACAP-27 and PACAP-38 (42 +/- 7% at 16 Hz) and by the antagonists VIP10-28 (29 +/- 9%) and PACAP6-38 (29 +/- 3%). The relaxation was also partly inhibited by L-NNA (51 +/- 12% at 16 Hz) and apamin (36 +/- 4%). The effects of a combination of apamin and L-NNA were additive, amounting to 75 +/- 3% inhibition. The effect of L-NNA reflected inhibition of NO release from nerve terminals, as well as NO generation in muscle cells by the action of VIP and PACAP; the effect of apamin reflected blockade of the action of PACAP. Thus, inhibitory transmission in guinea pig gastric fundus represents the combined actions of VIP, PACAP and NO released from nerve terminals and NO generated in muscle cells. The postjunctional actions of PACAP are mediated by a VIP/PACAP-II receptor and by a PACAP-specific, apamin-sensitive receptor.

Human galanin modulates human colonic motility in vitro. Characterization of structural requirements.

BACKGROUND: Human galanin (hGal) is a 30-residue non-amidated gut-brain peptide that shows considerable sequence divergence compared with galanin (Gal) forms of other species. Conflicting results have been reported with regard to the structural requirements for its modulatory action on gut motility. METHODS: We investigated the effect of human and rat Gal and substituted analogues of Gal on the contractility of longitudinal muscle strips of the human colon in vitro. RESULTS: Both hGal and rGal contracted the preparations in a concentration-dependent and tetrodotoxin-resistant manner without difference in sensitivity. The NH2-terminally truncated peptides hGal (3-30) and rGal (3-29) were inactive, whereas the NH2-terminal fragments, hGal (1-21) and rGal (1-18), remained fully responsive. Single amino acid substitutions at NH2-terminal positions showed divergent results: substitution of Trp2 reduced significantly potency and efficacy, whereas substitutions at positions 1, 3, 4, or 5 did not markedly modify the bioactivity of Gal. Galantide, a high-affinity Gal antagonist in the central nervous system, is a full agonist in human colonic smooth muscle. CONCLUSION: The COOH-terminal part of Gal contributes mainly the receptor-binding affinity of the peptide, whereas the NH2-terminal region is essential for biologic activity.

Specific monoclonal antibodies neutralize the action of PACAP 1-27 or PACAP 1-38 on intestinal muscle strips in vitro.

The gut-brain neuropeptide pituitary adenylate cyclase activating polypeptide (PACAP) is a novel highly conserved member of the secretin-glucagon-VIP peptide family comprising 38 or 27 amino acid residues. In this study, we investigate the actions of PACAP 1-27 or PACAP 1-38 on jejunal and caecal muscle strips from pig or guinea pig and demonstrate the neutralizing effect of two PACAP-specific monoclonal antibodies of the IgG1 subtype, RSP27II and RSP38. These antibodies were used to set up assay systems specific for PACAP 1-27 or PACAP 1-38. Monoclonal antibody RSP27II recognizes exclusively PACAP 1-27, whereas RSP38 binds only PACAP 1-38. PACAP 1-27 and PACAP 1-38 relax taenia caeci dose-dependently in the presence of guanethidine and scopolamine. Both peptides inhibit the spontaneous contractions of porcine jejunal muscle strips equipotently. Monoclonal antibodies RSP27II and RSP38 specifically neutralize the actions of either exogenously applied or endogenously released PACAP. Thus, they represent processing-specific tools to examine the physiological role of both molecular forms of PACAP in the gastrointestinal tract.

Regulation of the descending relaxation phase of intestinal peristalsis by PACAP.

The presence of pituitary adenylate cyclase-activating peptide (PACAP), a homologue of vasoactive intestinal peptide (VIP), in enteric neurons suggests that it may involved in the regulation of the descending relaxation phase of the peristaltic reflex. The role of PACAP was evaluated by measurement of PACAP release and by immuno-neutralization with specific monoclonal antibodies to PACAP-27 and PACAP-38, and an antibody to VIP. Electrical field stimulation at 4 Hz caused a 12-fold increase in PACAP release that was inhibited by 53 +/- 6% (P < 0.01) by the nitric oxide synthase inhibitor, NG-nitro-L-arginine (L-NNA). Orad stretch of colonic segments elicited descending relaxation and PACAP release in proportion to the degree of stretch. PACAP release induced by 10-g stretch was inhibited by 67 +/- 10% (P < 0.01) by L-NNA. Previous studies (Am. J. Physiol., 264 (1993) G334-G340) showed that orad stretch elicits also VIP release and nitric oxide (NO) production and that VIP release is inhibited (59%) by L-NNA. Preincubation of the segments with PACAP-27 plus PACAP-38 antibodies (50 micrograms/ml each), or with VIP antibody (1:60) inhibited descending relaxation at all degrees of stretch (inhibition with PACAP antibodies: 90 +/- 8% with 2-g and 22 +/- 5% with 10-g stretch). Preincubation with both PACAP and VIP antibodies virtually abolished descending relaxation. A similar pattern was observed with the antagonists, PACAP6-38 and VIP10-28, alone and in combination.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibitory transmission in tenia coli mediated by distinct vasoactive intestinal peptide and apamin-sensitive pituitary adenylate cyclase activating peptide receptors.

Inhibitory transmission in tenia coli involves both vasoactive intestinal peptide (VIP) and an apamin-sensitive transmitter. The present study examined whether pituitary adenylate cyclase activating peptide (PACAP) is released from tenia coli and accounts for the apamin-sensitive component of neurally mediated relaxation. Electrical field stimulation (0.25-4 Hz) elicited frequency-dependent relaxation and PACAP release; earlier studies had shown a similar pattern for VIP release and an absence of nitric oxide generation in this tissue. A combination of specific PACAP-27 and PACAP-38 monoclonal antibodies (each 100 micrograms/ml), the PACAP antagonist PACAP6-38 and desensitization with PACAP inhibited relaxation induced by all frequencies of stimulation. The magnitude of inhibition elicited by each treatment (38 +/- 3%-41 +/- 3% at 4 Hz) was similar to that elicited by apamin (44 +/- 11%) and was not augmented by apamin. VIP antibody (1:60), the VIP antagonist, VIP10-28 and VIP desensitization also inhibited relaxation (33 +/- 2%-35 +/- 5% at 4 Hz). Inhibition by each treatment was augmented additively by apamin (76 +/- 3%-85 +/- 3%) as well as by combination with PACAP antibody, PACAP antagonist and PACAP desensitization (76 +/- 6%-80 +/- 3%). Measurements in muscle strips and dispersed tenia coil muscle cells showed that VIP10-28 inhibited relaxation induced by VIP only, and PACAP6-38 inhibited relaxation mediated by PACAP-27 or PACAP-38 only, implying interaction of VIP and PACAP with distinct receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

PACAP is a stimulator of neurogenic contraction in guinea pig ileum.

The myotropic effect of pituitary adenylate cyclase-activating polypeptide (PACAP), a novel brain-gut peptide with high sequence homology to vasoactive intestinal polypeptide (VIP), was studied in the isolated guinea pig ileum in vitro. PACAP contracts the guinea pig ileum significantly more potently and efficiently compared with VIP. PACAP-induced contraction was abolished by tetrodotoxin, dynorphin, and somatostatin, partially reduced by atropine, and not affected by ganglionic and adrenergic blockade. The atropine-resistant component was sensitive to spantide, to the induction of tachyphylaxis with substance P, and to omega-conotoxin. Ileal strips desensitized to PACAP did not respond to VIP, although they maintained their sensitivity to PACAP after desensitization to VIP. COOH-terminal-truncated derivatives of PACAP exhibited full biological activity, although some of them showed substantially reduced potency. Deletion of NH2-terminal amino acids abolished biological activity. PACAP produced a concentration-dependent increase in the release of [3H]acetylcholine from longitudinal muscle-myenteric plexus preparations preloaded with [3H]choline. This effect was Ca2+ dependent, tetrodotoxin sensitive, and resistant to hexamethonium and scopolamine. In contrast, PACAP inhibited release of acetylcholine evoked by field stimulation. In summary, PACAP-induced contraction of the guinea pig ileum is mediated via release of acetylcholine and substance P through interaction with PACAP-1 and VIP/PACAP-2 receptors. PACAP has to be added to the list of myotropic neuropeptides of the gastrointestinal tract.

Pituitary adenylate cyclase-activating peptide is a potent modulator of human colonic motility.

Pituitary adenylate cyclase-activating peptide (PACAP) represents a novel brain-gut peptide with high sequence homology to vasoactive intestinal polypeptide (VIP). Since PACAP has been identified in the human gut, the effect of the two molecular forms PACAP-(1-38) and PACAP-(1-27), the hybrid PACAP-(1-23)VIP-(24-28), and VIP on the contractility of the longitudinal muscle of human sigmoid colon was tested in vitro. All peptides inhibited the spontaneous phasic contractions and relaxed concentration-dependently carbachol-precontracted preparations. The effects of the peptides remained unaffected by tetrodotoxin, by inhibition of phosphodiesterase activity, and by inhibition of nitric oxide synthesis. Apamin reduced only the effects of the PACAP peptides, whereas tetraethylammonium blocked only the effect of VIP. In conclusion, PACAP peptides and VIP mediate their relaxant effects via activation of specific PACAP and VIP receptors coupled to different potassium channels.

Pituitary adenylate cyclase activating polypeptide (PACAP) is a potent relaxant of the rat ileum.

The effect and mode of action of pituitary adenylate cyclase activating polypeptide (PACAP) were studied in rat ileal strips. PACAP relaxed, concentration dependently, rat ileum and was 50 times more potent than the structurally related vasoactive intestinal polypeptide (VIP). The inhibitory action of PACAP was not modified by TTX, omega-conotoxin, adrenergic, or ganglionic blockade, antagonists of adrenoreceptors and muscarinic receptors, indicating a direct myogenic effect probably through specific PACAP receptors. The lack of cross-tachyphylaxis between PACAP and VIP suggests that both peptides act by activation of distinct receptors. Structure-function analysis revealed that the N-terminal region of the PACAP molecule is crucial for biological activity.

Pituitary adenylate cyclase activating peptide, a novel VIP-like gut-brain peptide, relaxes the guinea-pig taenia caeci via apamin-sensitive potassium channels.

Effects of pituitary adenylate cyclase activating peptide (PACAP-(1-27)) and vasoactive intestinal polypeptide (VIP) on the guinea-pig taenia caeci were studied in the presence of guanethidine and scopolamine. Both peptides (1 nmol/1-1 mumol/l) concentration-dependently relaxed the smooth muscle of the taenia. PACAP-(1-27) and VIP were nearly equipotent. Apamin (30 nmol/l), a selective blocker of calcium-activated potassium channels, abolished the relaxation induced by PACAP-(1-27) whereas the effect of VIP remained unaffected. PACAP-(1-27) may be a candidate for the noncholinergic, non-adrenergic inhibitory neurotransmitter which induces apamin-sensitive relaxation in the intestinal tract.

Histamine inhibits 5-hydroxytryptamine release from the porcine small intestine: involvement of H3 receptors.

Strips of the porcine small intestine were incubated in vitro, and the release of 5-hydroxytryptamine (5-HT) was determined by high-pressure liquid chromatography with electrochemical detection. Removal of the mucosa resulted in a large reduction (95%) of tissue 5-HT, suggesting that enterochromaffin cells are the main source of 5-HT. The release of 5-HT was reduced by 70% after omission of calcium. Tetrodotoxin and hexamethonium reduced the release of 5-HT by 30%-40% in a nonadditive manner, indicating a spontaneous neuronal (nicotinic) excitatory input to the enterochromaffin cells. Histamine inhibited the release of 5-HT by about 50%. This effect was not affected by mepyramine or cimetidine but was effectively blocked by thioperamide, indicating the involvement of H3 receptors. The selective H3-receptor agonist R-alpha-methyl-histamine also inhibited 5-HT release. Because the effect of R-alpha-methyl-histamine was also observed in the presence of tetrodotoxin, an indirect, neuronally mediated action could be excluded. Therefore, the inhibitory H3 receptors may be localized directly at the enterochromaffin cells.

Vasoactive intestinal polypeptide induces neurogenic contraction of guinea-pig ileum. Involvement of acetylcholine and substance P.

The effect and mode of action of vasoactive intestinal polypeptide (VIP), a peptidergic neuromodulator in the gastrointestinal nervous system, were investigated in isolated muscle strips of the guinea-pig ileum. VIP induced concentration-dependent (20 nM-1 microM) contractions of longitudinal ileal strips. TTX (1 microM), a mixture of atropine (3 microM) and spantide (30 microM), a mixture of atropine (3 microM) and omega-conotoxin GVIA (100 nM), somatostatin (60 nM) and dynorphin (100 nM) abolished the effect of VIP. In most cases a small relaxation became evident. Desensitization to substance P in the presence of atropine prevented VIP-induced contraction. A partial inhibition was observed in the presence of atropine (3 microM), spantide (30 microM), omega-conotoxin GVIA (100 nM), beta-endorphin (265 nM), met-enkephalin (1100 nM) and a mixture of spantide (30 microM) and omega-conotoxin GVIA (100 nM). The action of VIP was not significantly modified by guanethidine (3 microM) or hexamethonium (150 microM). In circular ileal strips VIP (10-300 nM) caused concentration-dependent relaxations through a direct myogenic effect. These results indicate that the VIP produced contractions of the guinea-pig ileum are exclusively neurally mediated and involve a cholinergic as well as a noncholinergic-nonadrenergic (NANC) pathway. It is concluded that besides acetylcholine (Ach) VIP releases the peptidergic transmitter substance P from postganglionic nerve fibers of myenteric plexus. Opioid peptides and somatostatin modulate the activity of cholinergic and peptidegic nerves in the guinea-pig ileum. The release of substance P appears to depend completely on N-type voltage sensitive calcium channels.