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Inhibitory effect of the cannabinoid receptor agonist WIN 55,212-2 on pentagastrin-induced gastric acid secretion in the anaesthetized rat
No full textThe effect of the cannabinoid (CB) receptor agonist WIN 55,212-2 on gastric acid secretion was studied in the anaesthetized rat after stimulation with pentagastrin. WIN 55,212-2 (0.5-2 mg/kg, i.v.) was inactive on basal secretion but caused a marked inhibition (80%) of the acid secretion stimulated by pentagastrin (10 mu g/kg, i.v.). The enantiomer WIN 55,212-3 (1-3 mg/kg, i.v.) did not significantly modify basal or pentagastrin-induced acid secretion. The inhibitory effect of WIN 55,212-2 against pentagastrin was prevented by the administration of the selective cannabinoid CB1 receptor antagonists SR141716A (1-3 mg/kg, i.v.) and LY320135 (1 mg/kg, i.v.); by contrast, the CB2 receptor antagonist SR144528 (0.3- mg/kg, i.v.) was without effect. The selective CB2 receptor agonist JWH-015 (0.1-10 mg/kg, i.v.) was inactive on the increase of acid output stimulated by pentagastrin. These results suggest that the inhibitory effect of WIN 55,212-2 on pentagastrin-stimulated acid secretion in the anaesthetized rat is mediated by specific cannabinoid receptors. Moreover, the antagonism of WIN 55,212-2-induced effects by the selective CB1 receptor antagonists SR141716A and LY320135 together with the ineffectiveness of both the CB2 receptor agonist JWH-015 and the CB2 receptor antagonist SR144528 indicate that CB1 receptor subtypes are predominantly involved in the antisecretory effect of WIN 55,212-2
Gastrolesive potential of new nonsteroidal anti-inflammatory drugs (NSAIDs): an experimental study in the rat
No full textNitric oxide and prostaglandins mediate gastric effects of the nonsteroidal antiinflammatory drug amtolmetin guacyl
No full textEffects of histamine H2 receptor agonists and antagonists on the isolated guinea pig gallbladder.
No full textHistamine H-2 receptor-mediated responses were examined on cholecystokinin-octapeptide (CCK-8)-precontracted guinea pig gallbladder in vitro, testing histamine and a series of specific histamine H-2 receptor agonists and antagonists. Among the antagonists tested, zolantidine and compound SKF 92857 were previously shown to antagonize H-2 receptor-mediated responses in the heart, but not in the stomach. Histamine, in the presence of the H-1 receptor antagonist mepyramine (10 mu M), and the H-2 receptor agonists dimaprit, impromidine and amthamine, inhibited CCK-8 (3 nM)-induced contractions in a concentration-dependent fashion, with the following rank orders of potency: impromidine > amthamine > histamine > dimaprit (pD(2) values were 6.73 +/- 0.04, 5.44 +/- 0.07, 4.64 +/- 0.04 and 3.71 +/- 0.05, respectively). The maximal relaxation produced by dimaprit was significantly lower than that produced by histamine, as well as by impromidine and amthamine, which behaved as full agonists. All the H-2 receptor antagonists examined were able to inhibit amthamine-induced relaxation. Famotidine (pA(2) = 7.09 +/- 0.26), zolantidine (pA(2) = 6.54 +/- 0.11), compound SKF 92857 (pA(2) = 6.58 +/- 0.13) and aminopotentidine (pA(2) = 6.86 +/- 0.06) competitively antagonised the amthamine-induced effect, while iodoaminopotentidine produced surmountable antagonism only at low concentrations (1 mu M, pA(2) = 6.83 +/- 0.21). Finally, the slowly-dissociable antagonist loxtidine caused non-parallel displacement to the right of the concentration-response curve to amthamine (pK(B) = 7.55 +/- 0.24), with a significant depression of the maximal response to the agonist, even at the lowest effective concentration (0.3 mu M). In conclusion, histamine H-2 receptors in guinea pig gallbladder resemble those of the heart, as regards their sensitivity to zolantidine and compound SKF 92857, which, by contrast, were unable to antagonize histamine effects at gastric H-2 receptors in different experimental model
Gastric and cardiovascular effects of COX-1 and COX-2 selective non steroidal anti-inflammatory drugs
No full textGastric Effects of the Selective Cyclooxygenase-2 Inhibitor Colecoxib in the Rat: Functional and Histological Data
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Gastroprotective effects of amtolmetin guacyl: a new non steroidal antiinflammatory drug that activates inducible gastric nitric oxide synthase
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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