A new pyrilamine coated graphite electrode (CGE) based on pyrilamine-tetraphenylborate ion-pair (Pyra-TPB) as electroactive material has been described. The sensor exhibited a linear response with a good Nernstian slope over a relatively wide range of concentration. The membrane film of the electrode made of 3% (w/w) ion-pair, 48.5% DBP (w/w) and 48.5% PVC (w/w). The sensor displays Nernstian r...

Histamine and calcitonin gene-related peptide (CGRP) contribute to the pain perception. The aim of the present study is to clarify the interaction of histamine and CGRP in the perception of inflammatory pain. The effects of a histamine H1 receptor antagonist (pyrilamine, i.p.), an H2 receptor antagonist (ranitidine, i.p.) and a CGRP antagonist (CGRP 8-37, i.t.) on the formalininduced pain was s...

The actions of histamine and histamine antagonists on afferent nerve activity were investigated in the lateral line of Xenopus laevis. Histamine (0.002-2.0 mM) had no effect on spontaneous activity or excitatory responses to water motion. In contrast, pyrilamine, an H1 receptor antagonist, suppressed spontaneous activity beginning at 0.01-0.05 mM. Below 0.3 mM the suppression was often preceded...

In the porcine coronary artery, regenerated endothelium is dysfunctional as regards the responses to endothelium-dependent agonists. The current study aimed to determine the possible involvement of histamine in such dysfunction. Pigs were treated chronically with pyrilamine (H1 receptor inhibitor, 2 mg·kg(-1)·day(-1)) with part of their coronary endothelium and allowed to regenerate for 28 days...

Histaminergic receptors and neuronal nitric oxide synthase (nNOS) are co-expressed at high levels in the hippocampal neurons and alter anxiety-like behaviors in rodents. Since the dorsal hippocampus may be involved in modulation of anxiety-like behaviors, the aim of the present study was to assess whether the nitric oxide (NO) system in the dorsal hippocampus affects anxiety-like behaviors indu...

There is increasing evidence that a proton-coupled organic cation (H+/OC) antiporter facilitates uptake of various central nervous system-active drugs, such as the histamine H1 receptor antagonist diphenhydramine, into brain. The purpose this study was to clarify structural requirements for H+/OC antiporter-mediated hCMEC/D3 cells, an established in vitro model human blood-brain barrier, by usi...

In the present study, we have demonstrated that multiple first-generation H1-antagonists caused behavioral and EEG seizures in rats. The epileptogenic property of pyrilamine was more potent than either chlorpheniramine or diphenhydramine. In contrast, the second-generation H1-antagonists, loratadine and ebastine did not induce detectable epileptogenic activity. Intraperitoneal injection of hist...

Histamine Hi and H2 receptors are present in the canine renal circulation. We have examined the effects of H, and H2 receptor antagonists on autoregulation of renal blood flow in the dog. Renal arterial pressure was reduced in a step-wise fashion to 80 mm Hg by means of an adjustable aortic clamp positioned above the left renal artery. Infusion of H2 antagonists, cimetidine or ranitidine, into ...

One feature of allergic asthma, the EAR (early allergic reaction), is not present in the commonly used mouse models. We therefore investigated the mediators involved in EAR in a guinea-pig in vivo model of allergic airway inflammation. Animals were sensitized using a single OVA (ovalbumin)/alum injection and challenged with aerosolized OVA on day 14. On day 15, airway resistance was assessed af...