Carotenoid composition in the fruits of red paprika (Capsicum annuum var. lycopersiciforme rubrum) during ripening; biosynthesis of carotenoids in red paprika

The changes in the carotenoid pigments of the Capsicum annuum var. lycopersiciforme rubrum during maturation have been investigated quantitatively by means of a HPLC technique. In all of the chromatograms, 40 peaks were detected; 34 carotenoids were identified. The total carotenoid content of the ripe fruits was about 1.3 g/100 g of dry weight, of which capsanthin constituted 37%, zeaxanthin was 8%, cucurbitaxanthin A was 7%, capsorubin constituted 3.2%, and beta-carotene accounted for 9%. The remainder was composed of capsanthin 5,6-epoxide, capsanthin 3,6-epoxide, 5,6-diepikarpoxanthin, violaxanthin, antheraxanthin, beta-cryptoxanthin, and several cis isomers and furanoid oxides. The possible biosynthetic routes for the formation of minor carotenoids containing 3,5,6-trihydroxy-beta-, 3,6-epoxy-beta-, and 6-hydroxy-gamma-end groups are described.

Effects of endomorphin-1 on open-field behavior and on the hypothalamic-pituitary-adrenal system

The effects of endomorphin-1 (EM1) on behavioral responses and on the hypothalamic-pituitary-adrenal system were investigated in mice. Locomotor activity was measured in an "open-field" apparatus, with parallel recording of the numbers of rearings and groomings. Different doses of the peptide (250 ng to 5 microg) were administered to the animals intracerebroventricularly 30 min before the tests. EM1 caused significant increases in the locomotor activity and the number of rearings. The effect of EM1 on the basal corticosterone secretion was also investigated. At a dose of 5 microg, the peptide significantly increased plasma corticosterone level. The corticotropin-releasing hormone (CRH) antagonist alpha-helical CRH9-41, applied 30 min prior to EM1 administration, completely abolished the increases in both locomotion and the number of rearings and attenuated the corticosterone release evoked by EM1. These results suggest that the EM1 -induced increases in locomotion and rearing activity as well as the pituitary-adrenal activation are mediated by CRH.

Auto-inhibition of Ca(2+)/calmodulin-dependent protein kinase II by its ATP-binding domain

Ca(2+)/calmodulin dependent protein kinase (CaMPK) II is a key enzyme in many physiological processes. The enzyme is inactive unless Ca(2+)/CaM binds to it. In this inactive form CaMPK-II does not bind ATP suggesting that the ATP-binding domain is involved in an intramolecular interaction. We show here that F12, a 12 amino acid long peptide fragment of the ATP-binding domain (CaMPK-II(23-34), GAFSVVRRCVKV) can inhibit the Ca(2+)/CaM-dependent activity (IC(50) of 3 microM) but has no effect on the Ca(2+)/CaM-independent activity of CaMPK-II. Kinetic analysis exhibited mixed inhibition with respect to autocamtide-2 and ATP. The inhibition by F12 showed specificity towards CaMPK-II, but also inhibited CaMPK-I (IC(50) = 12.5 microM), while CaMPK-IV (IC(50) = 85 microM) was inhibited poorly and cAMP-dependent protein kinase (PKA) was not inhibited. Substitution of phenylalanine at position 25 to alanine (A12), had little effect on the inhibition of different Ca(2+)/CaM-dependent protein kinases, suggesting that phenylalanine 25 does not play a crucial role in the interactions involving F12. Thus the molecular interactions involving the ATP-binding domain appears to play a role in the regulation of nonphosphorylated CaMPK-II activity.

Changes of serum carotenoids in patients with esophageal, gastric, hepatocellular, pancreatic and colorectal cancer

The serum levels of carotenoids (vitamin A, lutein, zeaxanthin, alfa- and beta cryptoxanthin, alfa- and beta-carotene) were measured in healthy persons (n=40) and in 98 patients with different malignant gastrointestinal diseases (44 patients with colon adenocarcinoma, 21 with gastric cancer, 15 with hepatocellular adenocarcinoma, 10 patients with pancreas adenocarcinoma and eight patients with esophagus cancer). The serum levels of carotenoids were measured with high-pressure liquid chromatography. The sera of the patients were taken at the time of the diagnosis.

RESULTS

the measurements indicated that (1) the serum level of vitamin A and zeaxanthin were significantly lower in all of these groups (except of pancreas adenocarcinoma), but the extent of the A decrease was different in the patients with different types of gastrointestinal malignancy. The serum level of vitamin A was in the healthy subjects 2.072+/-0.332 mmol/l and in the case of gastrointestinal malignancies was 0.77+/-0.14 mmol/l (P<0.001) The serum level of zeaxanthin was in the healthy subjects 0.143+/-0.057 mmol/l and at the malignancies was 0.042+/-0.014 mmol/l (P<0.01). (2) There were no significant differences in the serum levels of other carotenoids in the checked groups. (3) The serum level of cholesterol, total protein, albumin and haemoglobin were in the normal range in these patients. These results indicate that the carotenoids may be responsible nutritional factors (as nutritional scavengers) in the development of different malignant diseases. This supposed role in the carcinogenesis does not depend fully on the vitamin A activity.

Biochemical basis of color as an aesthetic quality in Citrus sinensis

The biochemical basis of color as an aesthetic quality in mature fruit of navel and Valencia orange (Citrus sinensis) was determined. Saponification of the two major color-imparting components resolved by thin-layer chromatography, followed by reversed-phase high-performance liquid chromatography, revealed that these comprised acyl esters of (9Z)-violaxanthin and beta-citraurin. Identification of the chromophores was based on cochromatography and online spectral analysis. The color quality of flavedo of mature fruit was dependent on the content and relative amounts of (9Z)-violaxanthin and beta-citraurin. Quantitative results revealed that increased color intensity was associated with a decline in the (9Z)-violaxanthin:beta-citraurin ratio from greater than 50 to below 10, an increase in flavedo (9Z)-violaxanthin and beta-citraurin content, and that measurement of the mass and ratio of these carotenoids can be used to accurately color-grade orange fruit for local and export markets.

Leiden mutation (as genetic) and environmental (retinoids) sequences in the acute and chronic inflammatory and premalignant colon disease in human gastrointestinal tract

BACKGROUND

Tumor, calor, dolor, pallor and functio laesa are together involved in the different acute and chronic inflammatory processes. The processes involved in the inflammation are determined by differently acquired and hereditary factors. Recently the presence of a new genetic marker (Leiden point mutation) was found in Crohn's disease and ulcerative colitis. On the other hand, the GI mucosal integrity was proven on gastrointestinal mucosal damage to be produced by different chemicals, xenobiotics, drugs. In human observations, the serum level of retinoids (vitamin A, lutein, zeaxanthin, alpha-, beta-carotene) was proven in patients with chronic gastrointestinal inflammatory bowel disease. The aims of this study were (1) to measure the prevalence of Leiden mutation; (2) to identify the changes in the serum retinoid level in patients with Helicobacter pylori infection of the stomach (n=24), hepatitis C infection (n=75), ileitis terminalis (Crohn's disease; n=49), ulcerative colitis (n=35), colon polyposis (n=59) and adenocarcinoma in colon polyps (n=9), and 57 healthy persons were used in the control group; (3) to compare the directions of the changes in the measured parameters in the acute (H. pylori and hepatitis C infections), chronic (ileitis terminalis, ulcerative colitis) GI inflammatory diseases and in colon polyposis without and with malignisation.

METHODS

The Leiden mutation was measured by the method of polymerase chain reaction, the retinoid level in the patient's serum was measured by high liquid cromathografic method (HPCL).

RESULTS

(1) It has been found that the prevalence of Leiden mutation increased significantly in patients with ileitis terminalis (P<0.001), ulcerative colitis (P<0.001), colon polyposis (P<0.001) and with colon polyps with malignisation (P<0.01). (2) Serum level of vitamin A and zeaxantin were decreased significantly in all group of patients except for the group with H. pylori infections. (3) alpha- and beta-carotenes were found to be practically at the same level as those in the control groups, except in patients of colon polyps with malignisation. (4) The vitamin A, lutein, zeaxantin, alpha- and beta-carotenes were decreased in patients with ileitis terminalis.

CONCLUSIONS

(1) The essential role of retinoids (carotenoids) as environmental factors are suggested for keeping GI mucosal integrity in human healthy subjects and patients. (2) Leiden mutation, as a genetic marker, can be used in the screening of patients with ileitis terminalis, ulcerative colitis and colon polyposis (without and with malignisation). (3) An opposite direction can be found between the increased prevalence of Leiden mutation and decrease of serum levels of retinoids in group of patients with ileitis terminalis, ulcerative colitis and colon polyposis (without and with malignisation).

High-performance liquid chromatographic separation of enantiomers of synthetic amino acids on a ristocetin A chiral stationary phase

A macrocyclic glycopeptide, ristocetin A, was used as chiral stationary phase for the high-performance liquid chromatographic separation of enantiomers of 28 unnatural amino acids, such as analogues of phenylalanine, tyrosine and tryptophan, and analogues containing 1,2,3,4-tetrahydroisoquinoline, tetraline or 1,2,3,4-tetrahydro-2-carboline skeletons. Excellent resolutions were achieved for most of the investigated compounds by using reversed-phase or a new polar-organic mobile phase system. The conditions of separation were optimized by variation of the mobile phase composition, temperature and flow-rate.

Half-a-century of the "Körmend Growth Study"

The authors give a sketch about the "Körmend Growth Study" which is series of cross-sectional growth studies, carried out in Körmend, a small town in Western Hungary. The first investigation was carried out in 1958 (K-58) and it has been repeated every ten years (K-68, K-78, K-88, and K-98). All 3-18 year-old healthy boys and girls in nurseries and schools in Körmend were involved in the study. Twenty-three body measurements were taken. This paper focuses on changes in height, weight, and BMI. Means of these two body measurements show an increase from time to time (as a phenomenon of positive secular trend), however, the secular trend for increasing height and weight is declining. BMI follows a similar pattern.

Enteroclysis and spiral CT examination in diagnosis and evaluation of small bowel Crohn's disease

INTRODUCTION

During the last few decades introducing many of new radiologic methods, diagnostic conditions and facilities of Crohn's disease has became markedly improved. Appropriate using of these technics definitely modifies the management of patients with known or suspected Crohn's disease serving reliable information about extent, severity and possible complications of disease. Enteroclysis and Computed tomography are the two major and basic methods to disclose or confirme diagnosis of Crohn's disease, obtain appropriate inforination about disease either with mucosal, transmural or extraintestinal manifestation.

METHODS AND PATIENTS

We evaluated 281 patients who were referred in our institution under suspition of Crohn's disease. Enteroclysis and abdominal spiral CT in all cases were carried out usually within 1 week. The 172 patients underwent abdominal spiral CT as the primary examination to evaluate diagnostic value of spiral CT in this entity, while 109 patiens had enteroclysis followed by abdominal CT. In 11 cases we also perforined CT enteroclysis with administration of 0.5% methylcellulose solution thorough nasojejunal tube controlled by electric motor driven contrast pump. Results were compared with final clinical, pathological or surgical data were available.

RESULTS

From the 281 patients eventually 74 proved Crohn's disease; sensitivity and specificity of enteroclysis proved to be 96 and 98%, while spiral CT sensitivity and specificity was 94 and 95%, respectively. Enteroclysis was superior to the spiral CT in demonstration of early lesions and functional disorders, while spiral CT proved to be essential in evaluation of transmural and extraintestinal complications.

CONCLUSIONS

Regarding enteroclysis and spiral CT as complementary methods, they provide excellent results in diagnosis of Crohn's disease.

Convenient synthesis of 3,4-methano-1,2,3, 4-tetrahydroisoquinoline-3-carboxylic acid and its derivatives as doubly constrained nonproteinogenic amino acid derivatives

Three strategies for the synthesis of the novel, doubly constrained, 3,4-methano-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid and its derivatives were evaluated. Only cyclocondensation of the mono(triphenyl)phosphonium salt derived from 1, 2-bis(bromomethyl)benzene with N-alkoxycarbonyloxamates in 1, 2-dimethoxyethane in the presence of potassium carbonate and subsequent cyclopropanation with dimethylsulfoxonium methylide in dimethyl sulfoxide furnished suitable O- and N-protected derivatives of 3,4-methano-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid in a convenient way. A detailed 2D DQF-COSY and 2D NOESY NMR analysis of the rotational isomerism of the latter bicyclic amino acid derivatives was performed. Various O- and N-protection protocols were worked out to afford access to a whole range of new derivatives of the title amino acid, suitable for peptide synthesis.

Enteroclysis and spiral CT examination in diagnosis and evaluation of small bowel Crohn's disease

INTRODUCTION

During the last few decades introducing many of new radiologic methods, diagnostic conditions and facilities of Crohn's disease has became markedly improved. Appropriate using of these technics definitely modifies the management of patients with known or suspected Crohn's disease serving reliable information about extent, severity and possible complications of disease. Enteroclysis and Computed tomography are the two major and basic methods to disclose or confirme diagnosis of Crohn's disease, obtain appropriate inforination about disease either with mucosal, transmural or extraintestinal manifestation.

METHODS AND PATIENTS

We evaluated 281 patients who were referred in our institution under suspition of Crohn's disease. Enteroclysis and abdominal spiral CT in all cases were carried out usually within 1 week. The 172 patients underwent abdominal spiral CT as the primary examination to evaluate diagnostic value of spiral CT in this entity, while 109 patiens had enteroclysis followed by abdominal CT. In 11 cases we also perforined CT enteroclysis with administration of 0.5% methylcellulose solution thorough nasojejunal tube controlled by electric motor driven contrast pump. Results were compared with final clinical, pathological or surgical data were available.

RESULTS

From the 281 patients eventually 74 proved Crohn's disease; sensitivity and specificity of enteroclysis proved to be 96 and 98%, while spiral CT sensitivity and specificity was 94 and 95%, respectively. Enteroclysis was superior to the spiral CT in demonstration of early lesions and functional disorders, while spiral CT proved to be essential in evaluation of transmural and extraintestinal complications.

CONCLUSIONS

Regarding enteroclysis and spiral CT as complementary methods, they provide excellent results in diagnosis of Crohn's disease.

Ultrasound in Crohn's disease of the small bowel

OBJECTIVE

The purpose of this work is to prospectively evaluate high resolution ultrasonography with graded compression in the ability to detect Crohn's disease of the small bowel (CDSB) together with its complications and activity signs, compared with enteroclysis, CT and immunoscintigraphy in the mirror of the final diagnosis.

METHODS AND MATERIAL

In a series of 73 consecutive patients, who were referred for enteroclysis with suspected Crohn's disease of the small bowel computed tomography (CT), ultrasound (US), immunoscintigraphy with 99mTc labeled monoclonal antigranulocyte antibody (AGAb) examinations were performed within 10 days from each other. For the final evaluation the diagnosis of CDSB was based on combination of clinical and enteroclysis findings (73 cases) and in 17 cases additional surgical and pathological data were available. The results of other modalities were blinded to the radiologists performing and reading out the exams. The diagnostic values of each modality was assessed also in those 18 patients, who had early Crohn's disease. In the group of 43 patients with proven CDSB who had all the four imaging modalities, the modalities were compared in their ability to demonstrate various pathological conditions related to CD. Increased (>500 ml/min) flow measured by Doppler US in the superior mesenteric artery and increased color signs in the gut wall seen by power Doppler sonography were compared to CDAI.

RESULTS

Of the 73 patients the combination of enteroclysis and clinical tests demonstrated CDSB in 47. The sensitivity, specificity and accuracy of ultrasound were 88.4, 93.3 and 90.4%, respectively. Enteroclysis was the most accurate method. CT was more sensitive than US, but less specific. The accuracy of US, CT and scintigraphy were similar. In the group of 18 patients, who had early CDSB, the sensitivity of US decreased to only 67%, CT and scintigraphy had higher values. Intra- and perimural abscesses, and sinus tracts were also more frequently visualized by US, especially if they were small. US was superior than CT in detecting stenoses and skip lesions, but inferior to enteroclysis. US and CT detected more fistulas, than enteroclysis. Compared to CT, US detected more cases with mesenteric lymphadenopathy, equal cases with abscesses and free peritoneal fluids. In detecting mesenteric inflammatory proliferation CT, and in detecting colonic involvement CT and immunoscintigraphy were slightly superior than graded compression US. Patterns of mural stratification detected by ultrasound correlated well with the enteroclysis severity stages. There was only 59% agreement between increased superior mesenteric artery flow detected by Doppler sonography and CDAI, and 60.5% agreement between increased number of Color pixels in the gut wall measured by power Doppler and increased CDAI.

CONCLUSION

High resolution graded compression sonography is a valuable tool for detecting small intestinal Crohn's disease. It has similar diagnostic values as CT. However in early disease the sensitivity substantially decreases. In known Crohn's disease for following disease course, evaluating relapses and extramural manifestations US is an excellent tool. Doppler and Power Doppler activity measurements do not correlate well with the more widespread clinical activity index.

[22q11.2 chromosome deletion and velo-cardio-facial syndrome in a patient with tetralogy of Fallot]

Velo-cardio-facial syndrome includes the following clinical features: congenital heart anomaly, velo-pharyngeal malformations and dysmorphic facial features. In 80% of the patients microdeletion of the long arm of chromosome 22 can be detected. Many patients with DiGeorge syndrome have the same underlying chromosomal etiology, however the same deletion results in severe dysmorphic features, immune defect, hypocalcaemia and in severe mental retardation. In isolated heart defects deletion can be detected in about 15% of the patients. We report the detection of the microdeletion in a patient with tetralogy of Fallot, minimal dysmorphic facial features and normal psychomotor development. Early diagnosis of 22q11.2 chromosomal deletion is important for genetic counseling and further rehabilitation. We emphasize the importance of genetic screening in patients with isolated congenital heart defects.

Characterization of N,N(Me)2-Dmt-Tic-OH, a delta selective opioid dipeptide antagonist

N,N(Me)2-Dimethyl-tyrosine-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid-OH (N,N(Me)2-Dmt-Tic-OH) is a very selective delta opioid dipeptide with elevated antagonist activity. We have radiolabelled this compound by catalytic tritiation of the N,N(Me)2-Dmt(3',5'-I2)-Tic-OH precursor. The ligand labelled rat brain membranes with a Kd value of 0.42 nM and a Bmax of 63.12 fmol/mg protein. The new tritiated ligand showed high affinity for the delta opioid receptor whereas its binding at mu and kappa opioid receptors was weak. N,N(Me)2-Dmt-Tic-OH was able to inhibit the agonist-stimulated binding of the non-hydrolysable GTP analogue ¿35SGTPgammaS, thus attenuating the activation of G proteins via opioid receptors. This simple opioid dipeptide in both normal and labelled form may serve as a useful tool to study delta opioid receptors in vitro and in vivo.

Isolated massive pleural effusion caused by pancreatico-pleural fistula

BACKGROUND

Massive pleural effusions are uncommon but well-documented complications of chronic pancreatitis, usually caused by the development of a pancreaticopleural fistula. The mechanism of the fistula formation is thought to be rupture of the pancreatic duct or pseudocyst.

MATERIAL AND METHODS

In the past 7 years we have treated 5 patients with massive pleural effusion of pancreatic origin in the Surgical Department of Semmelweis University Medical School. 4 patients were males; the average age was 52 years (range: 46-59 years).

RESULTS

All 5 patients had a history of alcohol abuse and were admitted to the pulmonary department because of respiratory distress. Other symptoms such as abdominal pain, chest pain, or weight loss were not always present. The diagnosis was confirmed by a markedly elevated amylase level in the aspirated pleural fluid. Abdominal ultrasound, CT scan, and ERCP examinations were carried out in order to determine the cause of the pancreaticopleural fistula. Conservative (nonsurgical) treatment was effective within 3 weeks in only one case. The other 4 patients required surgical management. In 3 cases distal pancreatic resection with splenectomy and cholecystectomy was done. In one case cystojejunostomy was performed. All 5 patients have been cured with complete resolution of their pleural effusions.

CONCLUSIONS

Patients with large pleural effusions may have underlying pancreatitis with a pancreaticopleural fistula. It is important to establish this diagnosis because treatment may require operative interventions.

Microsatellites in different eukaryotic genomes: survey and analysis

We examined the abundance of microsatellites with repeated unit lengths of 1-6 base pairs in several eukaryotic taxonomic groups: primates, rodents, other mammals, nonmammalian vertebrates, arthropods, Caenorhabditis elegans, plants, yeast, and other fungi. Distribution of simple sequence repeats was compared between exons, introns, and intergenic regions. Tri- and hexanucleotide repeats prevail in protein-coding exons of all taxa, whereas the dependence of repeat abundance on the length of the repeated unit shows a very different pattern as well as taxon-specific variation in intergenic regions and introns. Although it is known that coding and noncoding regions differ significantly in their microsatellite distribution, in addition we could demonstrate characteristic differences between intergenic regions and introns. We observed striking relative abundance of (CCG)(n)*(CGG)(n) trinucleotide repeats in intergenic regions of all vertebrates, in contrast to the almost complete lack of this motif from introns. Taxon-specific variation could also be detected in the frequency distributions of simple sequence motifs. Our results suggest that strand-slippage theories alone are insufficient to explain microsatellite distribution in the genome as a whole. Other possible factors contributing to the observed divergence are discussed.

[Synthesis and in vitro receptor analysis of new potential oxytocin antagonists]

Oxytocin (OT) itself and the sensitivity of the uterus to OT play a crucial role in the initiation of both normal and pathologically early delivery. It recognition of the complex mechanism of action suggests that specific OT antagonists are of therapeutic value in postponing early contractions. In this study neurohypophyseal hormone analogues containing Sar in position 7, Arg in position 8, and various conformationally restricted or bulky derivatives of phenilalanine and tryptophan amino acids in position 2 were prepared to design more potent and selective OT antagonists. We determined the ligand-receptor binding characteristics of these newly synthetized peptides in the presence of [3H]oxytocin and [3H]vasopressin on isolated guinea-pig uterus, rat liver and kidney inner medulla plasma membranes. In the case of each peptides we calculated the Ki values and the selectivity ratio. The binding to the OT receptor was dramatically decreased for the Trp-derivatives containing analogues, while the Phe-derivatives containing analogues displayed a relatively high receptor affinity and have a relatively high OT/VP1 receptor selectivity.

Carotenoid composition in the fruits of Asparagus officinalis

The carotenoid pigments of the ripe and unripe fruits of Asparagus officinalis were investigated by means of an HPLC technique. Capsanthin, capsorubin, capsanthin 5,6-epoxide, antheraxanthin, violaxanthin, neoxanthin, mutatoxanthin epimers, zeaxanthin, lutein, beta-cryptoxanthin, beta-carotene, and some cis isomers were found. Carotenoids with 3,5,6-trihydroxy and 3,6-epoxy beta-end groups could not be deleted.

Genetic subtypes of HIV type 1 in Hungary

We examined the diversity of HIV-1 subtypes in 11 adults from Hungary, using the heteroduplex mobility assay (HMA) and DNA sequencing. HMA results showed that HIV-1 gp120 sequences from 10 patients were of subtype B, whereas 1 patient, infected in Africa, carried a subtype C strain. DNA sequencing confirmed the HMA results and revealed a high intrasubtype diversity in the C2V3 region of env in different clade B isolates, which suggests multiple introduction of subtype B to Hungary. This study shows that subtype B is the predominant HIV-1 clade in Hungary.

Deltorphin II analogues with 6-hydroxy-2-aminotetralin-2-carboxylic acid in position 1

Two approaches to the design of very active and highly selective delta opioid peptides were used to obtain new deltorphin analogues with altered hydrophobic and stereoelectronic properties. Deltorphin II analogues were synthesized with the substitution of Ile instead of Val at positions 5 and 6 in the address domain and 6-hydroxy-2-aminotetralin-2-carboxylic acid (Hat) instead of Tyr(1) in the message domain. In the radioreceptor-binding studies, in which type-specific tritiated opioid ligands were used, (R)- and (S)-Hat-deltorphins exhibited similar K(i) values, revealing high delta selectivity. The peptides displayed agonist properties in the in vitro bioassay, with IC(50) values in the subnanomolar range in the mouse vas deferens assay and in the micromolar or higher range in the guinea pig ileum assay, again demonstrating a high selectivity toward delta receptors. The agonist property of the new ligands was confirmed by means of [(35)S]GTPgammaS-binding experiments in membranes of the rat frontal cortex.

Evidence for the involvement of ATP, but not of VIP/PACAP or nitric oxide, in the excitatory effect of capsaicin in the small intestine

The contractile effect of capsaicin in the guinea-pig small intestine involves an activation of enteric cholinergic neurons. Our present data show that the P(2) purinoceptor antagonist pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid (PPADS, 30 microM) significantly reduces the contractile response to capsaicin (2 microM) in the presence, but not in the absence, of the tachykinin receptor antagonists [O-Pro(9), (Spiro-gamma-lactam)Leu(10), Trp(11)]physalaemin (1-11) (GR 82334; 3 microM) and (S)-(N)-(1-(3-(1-benzoyl-3-(3, 4-dichlorophenyl)piperidin-3-yl)propyl)-4-phenylpiperidine-4-yl)-N -methylacetamide (SR 142804: 100 nM) (for blocking tachykinin NK1 and NK3 receptors, respectively). PPADS (30 microM) fails to influence submaximal cholinergic contractions evoked by cholecystokinin octapeptide (CCK-8; 2-3 nM) or senktide (1 nM), or the direct smooth muscle-contracting effect of histamine (100-200 nM). A higher concentration (300 microM) of PPADS is also without effect against the stimulatory action of cholecystokinin octapeptide. This means that PPADS can probably be safely used as a purinoceptor antagonist in intestinal preparations. The putative pituitary adenylate cyclase activating peptide (PACAP) receptor antagonist PACAP-(6-38) (3 microM) significantly reduces the contractile effect of PACAP-(1-38) (10 nM) and abolishes that of vasoactive intestinal polypeptide (VIP; 10 nM). PACAP-(6-38) (3 microM) fails to influence the effect of capsaicin (2 microM) both in the absence and in the presence of tachykinin receptor antagonists. The nitric oxide (NO) synthase inhibitor N(G)-nitro-L-arginine (L-NOARG; 100 microM) also fails to inhibit the capsaicin-induced motor response. We conclude that an endogenous ligand of PPADS-sensitive P(2) purinoceptors (possibly ATP), but not a VIP/PACAP-like peptide or NO, is involved in the nontachykininergic activation of cholinergic neurons in the course of the capsaicin-induced contraction.