In this study the effect of adrenergic receptor agonists and antagonists on physostigmine induced yawning was investigated. Intraperitoneal injection of different doses of physostigmine (0.03, 0.05, 0.1 and 0.2 mg/kg) caused yawning in white rats. The greatest response was seen at a dose of 0.2 mg/kg physostigmine. Phenylephrine, an α1 agonist, and clonidine, an α2 agonist, led to a decrease in...

BACKGROUND The pathogenic mechanisms involved in Helicobacter pylori-induced duodenal mucosal injury are incompletely understood. In the present study, we sought to investigate the effect of H. pylori vacuolating cytotoxin (VacA) on duodenal mucosal bicarbonate (HCO3-) secretion. METHODS Concentrated bacterial culture supernatants from an H. pylori wild-type strain producing VacA with s1/m1 g...

Let G be a group which is hyperbolic relative to a collection of subgroups H1, and it is also hyperbolic relative to a collection of subgroups H2. Suppose that H2 ⊂ H1. We characterize, for subgroups of G, when quasiconvexity relative to H1 implies quasiconvexity relative to H2. We also show that quasiconvexity relative toH2 implies quasiconvexity relative toH1. As an application, we give some ...

Knowing the importance for research and pharmacological uses of proper ligand classification into agonists, inverse agonists, and antagonists, the aim of this work was to study the behavior of tiotidine, a controversial histamine H2 receptor ligand. We found that tiotidine, described previously as an H2 antagonist, actually behaves as an inverse agonist in U-937 cells, diminishing basal cAMP le...

The contributions of histamine (H1 or H2) receptor-mediated responses and, therefore, the effects of histamine blocking agents are unclear with regard to regulation of proximal epicardial and distal resistance coronary arteries. This study was designed to evaluate the effects of selective H1- and H2-receptor antagonists on epicardial and resistance vessels in the closed chest dog model. Histami...

The histamine H2-receptor antagonists have been identified as inhibitors of human liver aldehyde dehydrogenase (EC 1.2.1.3) isozymes, E1, E2, and E3. Inhibition was strongest with the E3 isozyme, whose substrates include gamma-aminobutyraldehyde, the aldehyde metabolites of polyamines, and betaine aldehyde. Burimamide, metiamide, cimetidine guanidine, cimetidine, and tiotidine were competitive ...

In the present study, the effects of caerulein and CCK receptor antagonist< on tolerance to the anti-pentylenetetrazol activity of diazepam has been studied. Different doses of diazepam (20, 30, 35, 40 and 50 mg/kg) were administered intraperitoneally for a period of 6 days in order to induce tolerance to diazepam. 48 h after the last dose of diazepam, a test dose of diazepam was tested for...

Oral antiplatelet therapy is central to the treatment of patients with thrombotic diseases. Yet, despite the proven efficacy of currently available agents such as aspirin and the P2Y12 receptor antagonist clopidogrel, and their advocacy in treatment guidelines, their efficacy and utilization remain suboptimal. This has prompted the search for more efficacious oral antiplatelet agents. Drug clas...