The mechanisms involved in tachykinin-induced neurokinin-1 (NK1) receptor-mediated edema formation have been studied in anesthetized wild-type and NK1 knockout mice. Intradermally injected substance P (30-300 pmol), NK1 agonists septide (3-30 pmol) and GR-73632 (3-30 pmol), and the mast cell-degranulating agent, compound 48/80 induced dose-dependent edema in wild-type skin, measured by the accu...

Anaphylactic histamine release from isolated rat peritoneal mast cells was concentration-dependently blocked by a 5-min treatment with exogenous histamine at 0.9 and 9 microM and enhanced by a 20- to 30-min treatment with thioperamide (H3-antagonist) at 3 microM with significance, but little affected by mepyramine (H1-antagonist) and cimetidine (H2-antagonist) at the cell concentration of 10(6)...

OBJECTIVE Crocin and safranal, as the major constituents of saffron, have many biological activities. This study investigated the effects of crocin and safranal on yawning response induced by intracerebroventricular (i.c.v.) injection of histamine in rats. MATERIALS AND METHODS In ketamine/xylazine-anesthetized rats, a guide cannula was implanted in the right ventricle of the brain and yawnin...

The effects of Mono sodium glutamate on smooth muscles were studied using the guinea-pig isolated ileum. Mono sodium glutamate produced spasmogenic effect. Atropine blocked the contractile response elicited by Mono sodium glutamate whereas mepyramine and hexamethonium failed to do so. These findings suggest a cholinergic involvement at post ganglionic site of action.

BACKGROUND Histamine is detected in high concentrations in the airways during an allergic asthma response. In a murine model of allergic asthma, JNJ 7777120, an antagonist at the histamine H(4) receptor, reduces asthmatic symptoms, while the histamine H(1) receptor-selective antagonist mepyramine is virtually without effect. In the present study, we analyzed the effect of combined antagonism at...

Systemic administration to rats of a combination of mepyramine, a histamine H1-, and burimamide, a histamine H2-receptor antagonist, over a period which included the time of implantation (late Day 5 to early Night 5), increased the number of blastocysts recovered from the uterus and reduced the number and intensity of Pontamine Sky Blue (PSB) sites obtained at autopsy on Night 5. Histological e...

1 Histamine produced dose-dependent contractile responses on both isolated perfused ear arteries and aortic strips of the rabbit. These responses were blocked by mepyramine and potentiated by both metiamide and dithiothreitol. 2 In the presence of maximum potentiation by metiamide, dithiothreitol still potentiated the contractile response to histamine of both preparations. 3 In the presence of ...

In the present study we investigated the participation of central H1 and H2 histaminergic receptors in water intake induced by hyperosmolarity (evoked by intragastric salt load), by hypovolemia (promoted by the subcutaneous administration of polyethyleneglycol) and by the pharmacological stimulation of central cholinergic pathways by the muscarinic agonist carbachol in male Wistar rats. The dat...

The role of the nucleus basalis magnocellularis (NBM) in fear conditioning encoding is well established. In the present report, we investigate the involvement of the NBM histaminergic system in consolidating fear memories. The NBM was injected bilaterally with ligands of histaminergic receptors immediately after contextual fear conditioning. Histaminergic compounds, either alone or in combinati...