AIMTo determine the involvement of extracellular signal-regulated kinase 1/2 (ERK1/2) pathway in the expression of endothelin receptor type B (ETB) during culture.

METHODSSB386023, a specific inhibitor for ERK1/2 pathway, was used to define the intracellular signaling pathway for the upregulation of ETB receptors and sarafotoxin 6c (S6c), a selective agonist for ETB receptors, induced contraction in isolated rat superior mesenteric arteries. The contraction was recorded by a sensitive in vitro myograph and the receptor mRNA was quantified by a real-time PCR. The phosphorylated ERK1/2 proteins were analyzed by phosphoELISA assay.

RESULTSS6c induced strong contractile responses of the artery after culture for 24 h, while there was no response to S6c in fresh vessel segments. The enhanced contractile response to S6c paralleled with an increase of mRNA for ETB receptors. The phosphorylated ERK1/2 proteins significantly increased after culture for 3 h. After co-culture with SB386023 for 24 h, S6c-induced contractions significantly decreased with reduction of Emax from (217 +/- 14) % to (127 +/- 23) % (P <0.01). This response paralleled with a decreased level of ETB receptor mRNA.

CONCLUSIONERK1/2 pathway was involved in the up-regulation of ETB receptors on smooth muscle cells isolated from rat mesenteric arteries during culture.

Animals ; Cells, Cultured ; Male ; Mesenteric Arteries ; cytology ; Mitogen-Activated Protein Kinase 1 ; antagonists & inhibitors ; metabolism ; Mitogen-Activated Protein Kinase 3 ; antagonists & inhibitors ; metabolism ; Muscle Contraction ; drug effects ; Muscle, Smooth, Vascular ; cytology ; metabolism ; Organ Culture Techniques ; Phosphorylation ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Sprague-Dawley ; Receptor, Endothelin B ; biosynthesis ; genetics ; Signal Transduction ; Up-Regulation ; Vasoconstrictor Agents ; pharmacology ; Viper Venoms ; pharmacology

AIMTo study the vasodilation effect of atropine and its mechanism.

METHODSIsometric tension was recorded in isolated rat super mesenteric arteries precontracted by noradrenaline (NE) to study the vasodilation effect of atropine, and to investigate the role of endothelial cell and vascular smooth muscle cell on vasodilation.

RESULTSAtropine was shown to significantly dilate the endothelium-intact and endothelium-denuded arteries precontracted by NE. Nomega-Nitro-L-arginine methyl ester (L-NAME, nitric oxide synthase inhabitor), indomethacin (cyclooxygenase inhibitor), propranolol (general beta adrenoceptor antagonist) and glibenclamide (ATP sensitive potassium channel inhibitor) showed no effect on vasodilation of atropine. Atropine did not affect the concentration-contraction curve of K+. However, atropine suppressed the contraction induced by NE and CaCl2, but not that by caffeine in the Ca+ -free Krebs solution.

CONCLUSIONAtropine showed significant vasodilation effect which may derive, in part, from endothelium. Besides, atropine could inhibit the receptor-mediated Ca2+ -influx and Ca2+ -release, which was inferred to the mechanism of atropine on vasodilation.

Animals ; Atropine ; pharmacology ; Calcium ; metabolism ; Calcium Chloride ; antagonists & inhibitors ; Cyclooxygenase Inhibitors ; pharmacology ; Endothelial Cells ; physiology ; Female ; In Vitro Techniques ; Indomethacin ; antagonists & inhibitors ; Male ; Mesenteric Artery, Superior ; drug effects ; NG-Nitroarginine Methyl Ester ; antagonists & inhibitors ; Nitric Oxide Synthase ; antagonists & inhibitors ; Norepinephrine ; antagonists & inhibitors ; Potassium Chloride ; antagonists & inhibitors ; Rats ; Rats, Sprague-Dawley ; Vasodilation ; drug effects ; Vasodilator Agents ; pharmacology

The Chinese herbal medicine Tianma (Gastrodia elata) has been used for treating and preventing primary headache over thousands of years, but the exact pharmacological mechanism of the main bioactive ingredient gastrodin remains unclear. In present study, the effects of gastrodin on calcitonin gene-related peptide (CGRP) and phosphorylated extracellular signal-regulated kinase1/2 (pERK1/2) expression were observed in rat trigeminal ganglion (TG) after in vitro organ culture to explore the underlying intracellular mechanism of gastrodin on primary vascular-associated headache. CGRP-immunoreactivity (CGRP-ir) positive neurons count, positive area, mean optical density and integrated optical density by means of immunohistochemistry stain were compared at different concentrations of gastrodin, which was separately co-incubated with DMEM in SD rat TG for 24 hours. Only at 5 or 10 mmol L(-1) concentration, gastrodin demonstrated significantly concentration-dependent reduction of CGRP-ir (+) expression and its action closed to 1.2 mmol L(-1) sumatriptan succinate. While at 2.5, 20, and 40 mmol L(-1) concentration, gastrodin did not show remarkable effects on CGRP-ir (+) expression. The optimal concentration of gastrodin (5 and 10 mmol L(-1)) similarly inhibited CGRP-mRNA expression level separately compared with 1.2 mmol L(-1) sumatriptan succinate and 10 micromol L(-1) flunarizine hydrochloride, which was quantitatively analyzed by real-time PCR (RT-PCR). pERK1/2 level was examined by Western blotting after co-cultured with optimal concentration of gastrodin and effective specific ERK1/2 pathway inhibitors PD98059, U0126. The result indicated that gastrodin significantly reduced pERK1/2 protein actions similarly to ERK1/2 pathway specific blockade. It suggests ERK1/2 signaling transduction pathway may be involved in gastrodin intracellular mechanism. This study indicates gastrodin (5 and 10 mmol L(-1)) can remarkably reduce CGRP-ir (+) neuron, CGRP-mRNA and pERK1/2 expression level in cultured rat TG, with its actions similar to the effective concentration of sumatriptan succinate, flunarizine hydrochloride and specific ERK1/2 pathway blocker. The intracellular signaling transduction ERK1/2 pathway may be involved in the gastrodin reducing CGRP up-regulation in rat TG after organ culture.
Animals ; Benzyl Alcohols ; administration & dosage ; isolation & purification ; pharmacology ; Butadienes ; pharmacology ; Calcitonin Gene-Related Peptide ; genetics ; metabolism ; Dose-Response Relationship, Drug ; Flavonoids ; pharmacology ; Flunarizine ; pharmacology ; Gastrodia ; chemistry ; Glucosides ; administration & dosage ; isolation & purification ; pharmacology ; MAP Kinase Signaling System ; drug effects ; Male ; Mitogen-Activated Protein Kinase 1 ; antagonists & inhibitors ; metabolism ; Mitogen-Activated Protein Kinase 3 ; antagonists & inhibitors ; metabolism ; Nitriles ; pharmacology ; Organ Culture Techniques ; Plants, Medicinal ; chemistry ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley ; Sumatriptan ; pharmacology ; Trigeminal Ganglion ; metabolism ; Vasoconstrictor Agents ; pharmacology ; Vasodilator Agents ; pharmacology

BACKGROUNDColorectal serrated polyp is considered as histologically heterogeneous lesions with malignant potential in western countries. However, few Asian studies have investigated the comprehensive clinical features of serrated polyps in symptomatic populations. The aim of the study was to evaluate the features of colorectal serrated polyps in a Chinese symptomatic population.

METHODSData from all consecutive symptomatic patients were documented from a large colonoscopy database and were analyzed. Chi-square test or Fisher's exact test and logistic regression analysis were used for the data processing.

RESULTSA total of 9191 (31.7%) patients were detected with at least one colorectal polyp. The prevalence of serrated polyps was 0.53% (153/28,981). The proportions of hyperplastic polyp (HP), sessile serrated adenoma/polyp (SSA/P), and traditional serrated adenoma (TSA) of all serrated polyps were 41.2%, 7.2%, and 51.6%, respectively, which showed a lower proportion of HP and SSA/P and a higher proportion of TSA. Serrated polyps appeared more in males and elder patients while there was no significant difference in the subtype distribution in gender and age. The proportions of large and proximal serrated polyps were 13.7% (21/153) and 46.4% (71/153), respectively. In total, 98.9% (89/90) serrated adenomas were found with dysplasia. Moreover, 14 patients with serrated polyps were found with synchronous advanced colorectal neoplasia, and large serrated polyps (LSPs) (odds ratio: 3.446, 95% confidence interval: 1.010-11.750, P < 0.05), especially large HPs, might have an association with synchronous advanced neoplasia (AN).

CONCLUSIONSThe overall detection rate of colorectal serrated polyps in Chinese symptomatic patient population was low, and distribution pattern of three subtypes is different from previous reports. Moreover, LSPs, especially large HPs, might be associated with an increased risk of synchronous AN.

Adult ; Age Distribution ; Aged ; Chi-Square Distribution ; Colonic Neoplasms ; diagnosis ; epidemiology ; Colonoscopy ; Colorectal Neoplasms ; diagnosis ; epidemiology ; Female ; Humans ; Logistic Models ; Male ; Middle Aged ; Prevalence