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C Surrenti

Publications and source records attributed to C Surrenti.

At least 55 records · Page 3Linked to original sources
PubMed1992

Capsaicin-like activity of N-ethylmaleimide in rat stomach.

1. N-Ethylmaleimide (NEM) and capsaicin induced a release of calcitonin gene-related peptide-like immunoreactivity (CGRP-li) in superfusates from rat gastric corpus. 2. The prior application of capsaicin completely blocked CGRP-li release by NEM while the exposure to NEM reduced the capsaicin-evoked CGRP-li outflow by about 51%. 3. These findings provide evidence that NEM might exert capsaicin-like activity in rat stomach and the release of CGRP-li from capsaicin-sensitive afferent fibres might influence the properties exerted by NEM in this tissue.

Animals↗
PubMed1992

Effects of sulglycotide on endogenous prostaglandin synthesis in human antral mucosa.

The effect of sulglycotide, a polysulphated glycopeptide isolated from pig duodenum, on PGE2, 6-ketoPGF1 alpha and TxB2 production from isolated biopsy specimens of human antral mucosa was investigated in vitro, in comparison with carbenoxolone. In addition to a tendency toward increased PGE2 production just short of statistical significance, both sulglycotide and carbenoxolone significantly increased 6-ketoPGF1 alpha accumulation in the incubation medium. TxB2 levels were not significantly modified by the two drugs. Therefore, changes in the prostanoid production by human antral mucosa could, at least partially account for the cytoprotective effects of sulglycotide in man.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

Ruthenium red selectively antagonizes capsaicin-induced release of vasoactive intestinal polypeptide (VIP) from the human colon.

Ruthenium red (RR) is an inorganic dye that has shown to block the actions of capsaicin on primary sensory neurons in different animal models. The aim of this study was to assess whether RR is able to antagonize the release of vasoactive intestinal polypeptide (VIP) evoked by capsaicin in the human colon. Samples of descending colon were collected from patients undergoing colectomy for carcinoma of the colon. Tissue slices from the muscle of human colon were exposed to either 10 microM capsaicin or an isotonic high K+ medium (KCl 80 mM), in the absence or presence of 10 microM RR. Either capsaicin or high K+ produced a prompt release of VIP. RR (10 microM) completely antagonized the capsaicin-induced release of VIP from muscle of human colon. This effect was elective, since VIP release evoked by high K+ was unaffected by the presence of RR. These findings indicate that RR acts as a selective antagonist of capsaicin in human tissue and that the mechanism underlying peptide release by capsaicin is preserved across species. Multiple mechanisms leading to VIP release exist in the human colon.

Aged↗
PubMed1991

Decrease of duodenal calcitonin gene-related peptide- and substance P-like immunoreactivity in rat duodenal ulcers.

We have investigated the endogenous levels of duodenal calcitonin gene-related peptide- (CGRP) and Substance P- (SP) like immunoreactivity (li) following the induction of duodenal ulcers in rats. Using three duodenal ulcerogens, namely cysteamine, dulcerozine or mepirizole given in a single oral dose, a decrease of duodenal CGRP-li and SP-li was observed. Time-relationship studies of this phenomenon show that CGRP-li and SP-li were decreased concomitantly to the formation of gastroduodenal ulcers after the administration of cysteamine (900 mg/kg p.o.). Pretreatment with the selective sensory neurotoxin capsaicin induced CGRP-li decrease in the duodenum, which was not further decreased by an ulcerogenic dose of cysteamine, indicating that cysteamine induced a release of CGRP-li of capsaicin-sensitive origin. Otherwise duodenal SP-li was not sensitive to capsaicin pretreatment and its duodenal content decreased by cysteamine originates from an intrinsic source. Our observations indicate that CGRP and SP may play an important local role in duodenal ulcerogenesis.

Animals↗
PubMed1991

Radioimmunoassay of epidermal growth factor in human saliva and gastric juice.

A sensitive radioimmunoassay was developed for human epidermal growth factor (hEGF) in saliva and gastric juice. This method was sufficiently sensitive for an accurate measurement of hEGF in these biological fluids. The minimal detectable concentration of EGF was 30 ng/L. The imprecision profile of EGF standard curve had a CV less than 10% in the range of 0.1-3.0 micrograms/L. Serial dilution curves of saliva and gastric juice paralleled that of standard EGF. The antibody to hEGF showed no cross-reactivity with a large excess of growth factors, such as human transforming growth factor alpha, human insulin-like growth factor I, and platelet-derived growth factor (c-sis). No detectable cross-reactivity was observed with some biological gut peptides: somatostatin, gastrin, secretin or pancreatic polypeptide. The intra-assay CV for saliva and gastric juice was less than 10%, and the recoveries were 93.9 +/- 8.7% and 93.7 +/- 11.3%, respectively for saliva and gastric juice. Gel exclusion chromatography revealed hEGF-like substances, heterogeneous in size in saliva and gastric juice, the origins and physiological functions of which are unknown.

Adult↗
PubMed1991

Calcitonin gene-related peptide increases the production of glycosaminoglycans but not of collagen type I and III in cultures of rat fat-storing cells.

We investigated whether calcitonin gene-related peptide (CGRP) was able to affect the production of collagen and glycosaminoglycans (GAG) in cultures of rat fat-storing cells (FSC). Rat CGRP (1 nM-1 microM) induced a dose-dependent increase of total GAG production in FSC cultures with an EC50 of 28 nM. One uM human CGRP (8-37) shifted the dose-response curve of rat CGRP to the right (EC50 = 257 nM) without depressing the maximal response. Salmon calcitonin (1 nM-1 microM) did not significantly modify total GAG accumulation in FSC cultures. Collagen type I and III production was not significantly affected by either CGRP or calcitonin in FSC cultures. These findings suggest that peripheral sensory neuropeptides may modulate liver fibrogenesis.

Adipose Tissue↗
PubMed1991

Capsaicin-induced release of neurokinin A from muscle and mucosa of gastric corpus: correlation with capsaicin-evoked release of calcitonin gene-related peptide.

It has been proposed that capsaicin-sensitive nerves might participate in a gastric defence mechanism, possibly via a local release of sensory neuropeptides. In this study, it was examined whether capsaicin might induce the release of neurokinin A (NKA), substance P (SP) and calcitonin gene-related peptide (CGRP) from different regions of rat stomach. Firstly, the tissue content of NKA-, SP- and CGRP-like immunoreactivity (LI) was measured in the fundus, in the corpus, in the muscle layer and in the mucosa of corpus of control rats and rats pre-treated with systemic capsaicin, s.c. (50 mg/kg as newborn). A large depletion (about 80%) of CGRP-LI following capsaicin treatment was observed in all regions examined, while no difference was observed for NKA-LI and SP-LI. NKA-LI, SP-LI and CGRP-LI release induced by capsaicin was measured in different regions of the rat stomach. Both in the gastric fundus and in the corpus, capsaicin (10 microM) produced a remarkable release of of CGRP-LI and NKA-LI, but not of SP-LI. A second administration of the drug had no longer effect, indicating desensitization. In the gastric corpus, the capsaicin-induced NKA-LI and CGRP-LI release was larger from the muscle layer than from the mucosa. The present findings provide neurochemical evidence that both NKA-LI and CGRP-LI are released from different regions of the rat stomach and both peptides should therefore be taken into account when considering the efferent function of capsaicin-sensitive primary afferents at gastric level.

Animals↗
PubMed1991

Enzyme immunoassay for tachykinin-like immunoreactivity in the guinea pig spinal cord.

A solid-phase enzyme immunoassay for quantitation of tachykinin-like immunoreactivity (TK-LI) is presented. Because the antiserum K-12 recognizes various tachykinins, such as neurokinin A (100%), kassinin (103%), eledoisin (51%), neurokinin B (18%), physalaemin (0.7%), and substance P (0.7%), the immunoreactivity detected in this enzyme immunoassay has been termed TK-LI. The assay was performed on 96-well microtiter plates coated with a mouse monoclonal second antibody. After preincubation of soluble neurokinin A or samples and K-12 antiserum for 3 h at room temperature, acetylcholinesterase-labelled neurokinin A was allowed to react overnight at 4 degrees C. Samples were finally incubated with Ellman's reagent for 2 h and the absorbance was measured at 414 nm. The threshold for detection of TK-LI was 2 fmol/well. TK-LI release from guinea pig dorsal spinal cord slices was evoked by capsaicin or high K+ medium. The capsaicin-evoked TK-LI release was increased in the presence of thiorphan, but not in that of captopril.

Acetylcholinesterase↗
PubMed1991

Sensory nerves in the gastrointestinal tract: changing concepts and new perspectives.

In recent years great interest has been directed to study the function of capsaicin-sensitive primary afferents in the gastrointestinal tract. It has been demonstrated that these fibers not only have a sensory role but also play a local efferent function through direct and indirect effects of released neurotransmitters. Peptides released by capsaicin-sensitive nerves are involved in several functions modulating either the local blood flow or the gastrointestinal motility. The analysis of the action of released transmitters may serve to understand the physiology and pathophysiology of the gastrointestinal tract. All data here reported demonstrate that the study of capsaicin-sensitive primary afferents may be helpful to develop new pharmacological treatment of various human disease of the gastrointestinal tract.

Animals↗
PubMed1991

Transforming growth factors beta 1 and beta 2 are differentially expressed in fibrotic liver disease.

Transforming growth factor (TGF) beta 1 has been implicated in the control of hepatocyte growth and stimulation of extracellular matrix synthesis in acute and chronic liver disease. The cellular localization of transforming growth factor (TGF) beta 1 and beta 2 RNA transcripts was determined in normal and fibrotic liver by in situ hybridization with [35S]-labeled RNA probes in combination with immunostaining for cell type characteristic markers. Fibrotic specimens were from patients with hepatitis B virus infection or alcohol abuse and rats with fibrosis secondary to bile duct ligation and scission. In normal liver, low levels of TGF beta 1 transcripts were found in some portal tract stromal cells, and TGF beta 2 RNA was not detectable. In fibrotic liver, high TGF beta 1 RNA levels were present in most mesenchymal liver cells, in most inflammatory cells, and in few bile duct epithelial cells. Hepatocytes did not express this cytokine with the exception of few limiting plate hepatocytes in cases of human cirrhosis with high activity. TGF beta 2 transcripts were detected at high levels in proliferating bile ducts of fibrotic livers, but were absent in all other cell types. TGF beta 1 expression in the liver is thus a function predominantly of mononuclear and mesenchymal cells as well as of some hepatocytes, whereas TGF beta 2 expression is a specific property of bile duct epithelial cells that may be related to the formation of specialized periductular connective tissue during bile duct proliferation.

Animals↗
PubMed1991

Prognosis in primary biliary cirrhosis. A review.

Recent progress has been made in estimating prognosis in primary biliary cirrhosis using Cox models. These models have also demonstrated the therapeutic value of liver transplantation by comparing the observed survival for a group after transplantation with the expected survival without transplantation calculated from the Cox prognostic model. However, good risk patients and those not transplanted principally for hepatocellular failure may not have a survival advantage for many years. Cox models have several limitations: the selection criteria for the patient populations used to derive the models, the selection of the time at which the patients are evaluated, the poor prognostic accuracy for individual patients rather than patient groups and lastly the fact that they use variables derived at only one time point-time independent Cox models. Thus new statistical tools must be used to improve prediction of survival in individual patients with PBC in order to optimize timing of liver transplantation. In addition a more precise definition of the natural history of both symptomatic and asymptomatic forms of this disease is needed to evaluate the efficacy of therapeutic agents in randomized clinical trials. However, although use and timing of therapeutic intervention, including liver transplantation, still requires good clinical experience and judgement, statistical modelling does give some objective measurement of prognosis, which is useful for the clinician treating patients with PBC. At the same time that new treatments are being evaluated, there is an obvious need to improve prognostic tools for application to individual patients with PBC. This may be achieved by using serial data in a different form of modelling-time dependent Cox models.

Humans↗
PubMed1991

Duodenal ulcer and Sjogren's syndrome in patients with primary biliary cirrhosis: a casual association?

Peptic ulcer has been reported in patients with primary biliary cirrhosis (PBC), but its frequency and pathogenesis are still poorly defined. We have analyzed the occurrence of duodenal ulcer in 37 female patients affected by PBC and in 35 with chronic liver disease of various etiologies. An active ulcer was found in seven patients with PBC and in one with chronic autoimmune hepatitis. The presence of an exocrine gland defect, as indicated by clinical signs of Sjogren's syndrome (SS), was found in six patients with PBC and duodenal ulcer (85%), but in only eight (26.6%) of those without ulcer (p less than 0.02). Therefore, in our patients, duodenal ulcer occurs more often in PBC than in other types of chronic liver disease. The association of SS with PBC, significantly higher in patients with than without ulcer, supports the hypothesis that the underlying exocrine gland defect is involved in the development of duodenal ulcer.

Adult↗
PubMed1990

Duodenal SP-like immunoreactivity is decreased in experimentally-induced duodenal ulcers.

Substance P-like immunoreactivity (SP-li) is decreased in duodenal samples of animals treated with a single dose of an ulcerogen such as dulcerozine, mepirizole or cysteamine. Unlike dulcerozine- or mepirizole-induced ulcers the degree of cysteamine-induced duodenal lesions is inversely correlated with the levels of duodenal SP-li. A significant decrease in duodenal SP-li was observed at 24 h, but not at 6 h after a single oral dose of cysteamine. These findings show that endogenous SP may play an important local role in duodenal ulcerogenesis.

Animals↗
PubMed1990

Oral S-adenosylmethionine in the symptomatic treatment of intrahepatic cholestasis. A double-blind, placebo-controlled study.

Parenteral S-adenosylmethionine proved to be effective in reversing intrahepatic cholestasis in pregnant women. Based on these findings, a prospective multicenter, double-blind, placebo-controlled trial was planned to assess whether oral S-adenosylmethionine is effective in cholestatic patients with chronic liver disease. Accordingly, 220 inpatients (26% chronic active hepatitis, 68% cirrhosis, 6% primary biliary cirrhosis) with stable (1 month or more) at least twofold increases in serum total and conjugated bilirubin and alkaline phosphatase volunteered for the trial. Serum markers of cholestasis significantly (P less than 0.01) decreased after oral S-adenosylmethionine administration (1600 mg/day), and their values were significantly (P less than 0.01) lower than the corresponding values in the placebo group. S-adenosylmethionine significantly (P less than 0.01) improved subjective symptoms such as pruritus, fatigue, and feeling of being unwell, whereas placebo was ineffective. Two patients in the S-adenosylmethionine group and 9 controls (P less than 0.05) withdrew from the trial for reduced compliance because of inefficacy of treatment. Oral S-adenosylmethionine was tolerated to the same extent as placebo. In conclusion, short-term administration of oral S-adenosylmethionine is more effective than placebo in improving clinical and laboratory measures of intrahepatic cholestasis and offers a new therapeutic modality for the symptomatic management of this syndrome.

Administration, Oral↗
PubMed1990

Effect of sensory denervation with capsaicin on liver fibrosis induced by common bile duct ligation in rat.

Hepatic fibrosis represents an important stage in the progression of chronic liver disease to cirrhosis. In the present paper we have investigated whether capsaicin-sensitive neuropeptide-containing sensory neurons may participate in the development of liver fibrosis. The expression of hepatic fibrosis induced by common bile duct obstruction has been studied both in capsaicin- and vehicle-treated rats. Common bile duct-induced liver fibrosis was less marked in capsaicin-treated rats than in vehicle-treated rats. Diffuse alterations of liver parenchyma structure with marked collagen deposition and nodular regeneration occurred 8 weeks after common bile duct ligation in vehicle-treated animals, while none of the capsaicin-treated rats exhibited the formation of complete connective septa altering the parenchyma architecture. Both vehicle- and capsaicin-treated rats showed an increasing number of desmin-positive cells in the perivenular zone, but the density of these cells was lower in treated animals than in untreated rats. The hydroxyproline content of the liver increased after common bile duct ligation in a time-dependent manner. Eight weeks after bile duct obstruction vehicle-treated rats showed a 7-fold increase of liver collagen content in comparison to normal animals. This enhancement was about 3.5-fold in capsaicin-treated rats. These findings raise the possibility that the peripheral release of neuropeptides stored in sensory nerves might participate in the development of liver fibrosis following common bile duct obstruction.

Animals↗
PubMed1990

Cigarette smoking increases gastric luminal prostaglandin F2 alpha and thromboxane B2 in healthy smokers.

Pentagastrin-stimulated gastric luminal prostaglandin E2 (PGE2), 6-keto-PGF1 alpha, PGF2 alpha and thromboxane B2 (TxB2) were measured using a second antibody solid-phase enzyme immunoassay before, during and after cigarette smoking in healthy smokers. Smoking significantly increased PGF2 alpha and TxB2 concentration and output; in contrast no significant changes were found for PGE2 and 6-keto-PGF1 alpha levels. In addition, cigarette smoking caused a significant reduction in gastric juice volume and acid output but did not alter intragastric acidity. These findings may suggest a possible role of prostanoids in the response of the stomach to cigarette smoking.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

Effects of plasma exchange (PE) in primary biliary cirrhosis (PBC). A pilot study.

Six patients were studied to evaluate the efficacy and safety of plasma exchange (PE) in the treatment of primary biliary cirrhosis (PBC). All patients were affected by PBC at stage III-IV and presented symptoms refractory to pharmacologic therapy. Patients underwent PE for a mean period of 40 weeks (range 10-88). A mean of 33 liters (range 17-64) of plasma per patients was removed. Patients reported less fatigue (4/6), pruritus (5/5), nausea (3/3), Sjogren's syndrome (2/6), and painful neuropathy (2/3). A reduction of xanthomata was noted in one of the three affected patients. Definitive improvement was seen in the patient with Raynaud's phenomenon. A significant reduction was noted for serum cholesterol and gammaglobulins. ALT, AST, gamma-GT, alkaline phosphatase, bilirubin, prothrombin activity, AMA titers were not affected by PE. All patients suffered some mild adverse effects during PE. Two patients (IV stage) developed late edema and ascites after 34 and 44 weeks of treatment. We conclude that PE can be considered effective chronic treatment for advanced symptomatic PBC refractory to pharmacological therapy.

Aged↗