M2muscarinic receptors limit acetylcholine release from the pulmonary parasympathetic nerves. M2receptors are dysfunctional in antigen-challenged guinea pigs, causing increased vagally mediated bronchoconstriction. Dysfunction of these M2 receptors is due to eosinophil major basic protein, which is an antagonist for M2 receptors. Histamine-induced bronchoconstriction is composed of a vagal refl...

Histamine is a biogenic amine with extensive effects on many cell types, mediated by the activation of its four receptors (H1R-H4R). Distinct effects are dependent on receptor subtypes and their differential expression. Within the gastrointestinal tract, histamine is present at relatively high concentrations, particularly during inflammatory responses. In this review, we discuss the immunoregul...

The type I cells are the chemoreceptive elements of the carotid bodies and are critical in defining the ventilatory response to hypoxia and hypercapnia. Recent evidence has suggested that histamine is released by the carotid body in response to hypoxia and acts as an excitatory neurotransmitter. Here we use isolated neonatal rat type I cells to assess the presynaptic actions of histamine and de...

OBJECTIVE To study the effect of granulocyte macrophage-colony-stimulating factor (GM-CSF) on histamine metabolism in arteriosclerosis, the expression of histidine decarboxylase (HDC; histamine-producing enzyme), histamine receptors 1 and 2 (HH1R and HH2R), and GM-CSF was investigated in human and mouse arteriosclerotic carotid arteries. Furthermore, the molecular mechanisms of GM-CSF-induced H...

In addition to its well-characterized effects in the acute inflammatory and allergic responses, histamine has been shown to affect chronic inflammation and regulate several essential events in the immune response. Histamine can selectively recruit the major effector cells into tissue sites and affect their maturation, activation, polarization, and effector functions leading to chronic inflammat...

The atherosclerotic intimal lesion contains endothelial cells, smooth muscle cells, monocytes/macrophages and T lymphocytes, which constitute a histamine-cytokine network that participates in chronic inflammatory responses. Monocytes/macrophages and T lymphocytes express the histamine-producing enzyme histidine decarboxylase (HDC), and specific histamine receptors (HHR), which are switched from...

INTRODUCTION: Epidemiological studies have reported that greater cardiorespiratory fitness (CRF) is associated with lower blood pressure (BP). Histamine receptor-mediated peripheral vasodilation contributes to post-exercise hypotension and lowing exercising BP responses. Previously, our laboratory found overactive responses exercise were induced by the inability of histamine receptors in indivi...

Dopamine has an effective role on gastric acid secretion (GAS). The role of peripheral and central dopamine D1/DA1 receptors on stimulated GAS are unknown. The objective of the present study was to use SKF38393 and SCH23390 on stimulated GAS. For all gastric sampling, animals (Sprague Dawley rats) were anesthetized and a polyethylene tube was introduced into the stomach through esophagus and a ...