The diverse functions of histamine are mediated by four specific histamine receptor subtypes, which belong to the family of G-protein-coupled receptors. Here, we summarize data obtained with histamine-deficient L-histidine decarboxylase knockout and histamine receptor subtype knockout mice in inflammation models. Advantages and disadvantages of the knockout approaches compared with pharmacologi...

Histamine is an accepted neurotransmitter and/or neuromodulator in the central nervous system (CNS). Its neuronal system in the brain is well organized, with cell bodies localized in a small area of the posterior hypothalamus. Diverse biological actions of histamine are mediated via three classes of receptors termed H1, H2, and H3. The existence of other histamine receptor subtypes is likely in...

It has been well established that cardiac actions of histamine are mediated by histamineHI and H2 receptors and that there exist specific agonists and antagonists acting on them (1.2.3:4.5.7.8 and 11). Cyclizine. an antihistamine has been shown to antagonize positivechronotropic effect of histamine which is mediated through H2 receptors (8) and to possessantiarrhythmic effect in experiernntal c...

The aim of the present study was to investigate whether and by which mechanism; histamine can induce state-dependent retrieval of passive avoidance task. The pre-training or pre-test intracerebroventricular (i.c.v.) injection of histamine (20µg/mouse) impaired retrieval, when it was tested 24 h later. In the animals, which retrieval was impaired due to histamine pre-training administration, pre...

To determine whether neuronal histamine influences development of histamine H-1 receptors in the rat brain, neonates were given diphenhydramine, an H-1 antagonist, daily for the first 21 days of postnatal life. In control rats, specific H-1 binding of [3H]mepyramine in whole brain was low at birth and increased progressively toward adult levels by the end of the 3rd week. Animals treated with d...

Mast cell has a long history of being recognized as an important mediator-secreting cell in allergic diseases, and has been discovered to be involved in IBD in last two decades. Histamine is a major mediator in allergic diseases, and has multiple effects that are mediated by specific surface receptors on target cells. Four types of histamine receptors have now been recognized pharmacologically ...

Norepinephrine, epinephrine, and histamine cause a rapid increase in the concentration of adenosine 3':5'-cyclic monophosphate (cAMP) in a tumor astrocyte cell line derived from a primary culture of a human glioblastoma multiforme. The catecholamine-induced increase in cAMP is dependent on the cell density, being far greater in cells in the log phase of growth than in cells near terminal densit...

In the heart, histamine (H3) receptors may function as inhibitory presynaptic receptors that decrease adrenergic norepinephrine release in conditions of enhanced sympathetic neural activity. We hypothesized that H3-receptor blockade might improve cardiovascular function in sepsis. In a canine model of Escherichia coli sepsis, we found that H3-receptor blockade increased cardiac output (3.6 to 5...

The diverse functions of histamine are mediated by four specific histamine receptor subtypes, which belong to the family of Gprotein-coupled receptors. Here, we summarize data obtained with histamine-deficient L-histidine decarboxylase knockout and histamine receptor subtype knockout mice in inflammation models. Advantages and disadvantages of the knockout approaches compared with pharmacologic...

Absract The collective of Professor Puscas sugests a theory The pH theory, which presents as a common element of these three receptors (for histamine, acetylcholine and gastrine)the carbonic anhydrase. According to this theory histamine, gastrine and acetylcholine have a dual effect on the parietal cell: one known, that their specific receptor binding, and the second effect, that the activation...