Histamine H1 receptors

Fibromyalgia is a painful disorder of unknown aetiology that presents activation and recruitment of innate immune cells, including mast cells. Efforts have been made to understand its pathogenesis to manage it better. Thus, we explored the involvement of peripheral mast cells in an experimental model of fibromyalgia induced by reserpine. Reserpine (1 mg/kg) was subcutaneously (s.c.) injected once daily in the back of male Swiss mice for three consecutive days. We analysed mechanical and cold allodynia, muscle fatigue and number of mast cell in plantar tissue...

BACKGROUND: Cholinergic urticaria (CholU) is a common subtype of chronic inducible urticaria, where signs and symptoms (eg, pruritic wheals and angioedema) are triggered by sweating due to physical exercise, passive warming and by other sweat-inducing situations. While guidelines recommend second-generation H1 antihistamines (sgAHs), ∼90% of patients report uncontrolled disease. Targeting the histamine 4 receptor (H4R) has shown promise in preclinical/clinical studies of allergic/inflammatory diseases...

The purpose of this study was to gain insight into histamine's role in the exercise inflammatory response and recovery from exercise. To explore this, young healthy participants (n = 12) performed 300 eccentric leg extensions under control (Placebo) versus histamine H1 and H2 receptor antagonism (Blockade) in a randomized cross-over study. Circulating leukocytes and cytokines were measured for 72 h after exercise. Circulating leukocytes were elevated at 6 and 12 h after exercise (p < 0...

Headache is one of the most common neurological disorders in children. The most common headache in children is a primary headache, including migraine and tension-type headache, but note that secondary headaches should be differentiated as a cause of headache in pediatric patients. The management of cedar pollinosis in pediatric patients is important because it can cause quality-of-life deficits in addition to nasal and ocular symptoms. Omalizumab, an anti-immunoglobulin E (IgE) monoclonal antibody, is approved in Japan as an add-on treatment option for severe cedar pollinosis, but few studies have investigated its real-world clinical efficacy in pediatric patients with seasonal allergic rhinitis...

[This retracts the article DOI: 10.1155/2019/6261951.].

Histamine receptors are a group of G protein-coupled receptors (GPCRs) that play important roles in various physiological and pathophysiological conditions. Antihistamines that target the histamine H1 receptor (H1 R) have been widely used to relieve the symptoms of allergy and inflammation. Here, to uncover the details of the regulation of H1 R by the known second-generation antihistamines, thereby providing clues for the rational design of newer antihistamines, we determine the cryo-EM structure of H1 R in the apo form and bound to different antihistamines...

Purpose: To investigate the in vivo efficacy of epinastine cream in type I allergic models. Methods: The dose, timing, and antiallergic effect of epinastine cream on the conjunctiva were evaluated postapplication to the eyelid skin of guinea pigs with histamine- or ovalbumin-induced allergic conjunctivitis. Additionally, we assessed its antiallergic effects on the skin postapplication to the dorsal skin of guinea pigs with ovalbumin-induced passive cutaneous anaphylaxis. Efficacy was estimated by determining the amount of dye that leaked from conjunctival or dorsal skin tissue vessels as a measure of vascular permeability, scoring the severity of allergic symptoms, and observing the scratching behaviors using clinical parameters...

BACKGROUND: Cariprazine is a third-generation antipsychotic with a unique mechanism of action. It functions as a partial agonist with high affinity for dopamine D2 and D3 and serotonin 5-HT1A receptors, an antagonist for 5-HT2A (moderate affinity) and 5-HT2B (high affinity) receptors. It binds to histamine H1 receptors and has a low affinity for 5-HT2C and alpha 1A-adrenergic receptors and no affinity for muscarinic (cholinergic) receptors. Among the troubling side effects, symptoms related to impulse control, such as hypersexuality, pathological gambling, compulsive shopping, compulsive eating etc...

BACKGROUND: Atopic dermatitis (AD) is a highly prevalent inflammatory skin disorder characterized by episodic exacerbations and remissions. Why the clinically healthy skin of AD patients becomes rapidly inflamed and very pruritic is poorly understood. OBJECTIVE: To investigate cowhage- and histamine-induced itch and skin expression levels of their target receptors in lesional and non-lesional skin of AD, compared to the skin of patients with psoriasis, chronic spontaneous urticaria (CSU) and healthy subjects...

Meclizine (Antivert, Bonine) is a first-generation H1 antihistamine used in the treatment of motion sickness and vertigo. Despite its wide medical use for over 70 years, its crystal structure and the details of protein-drug interactions remained unknown. Single-crystal X-ray diffraction (SC-XRD) is previously unsuccessful for meclizine. Today, microcrystal electron diffraction (MicroED) enables the analysis of nano- or micro-sized crystals that are merely a billionth the size needed for SC-XRD directly from seemingly amorphous powder...

The histamine H3 receptor, prominently expressed in neurons with a minor presence in glial cells, acts as both an autoreceptor and an alloreceptor, controlling the release of histamine and other neurotransmitters. The receptor impacts various essential physiological processes. Our team's initial investigations had demonstrated that the histamine H3 receptor antagonists could facilitate the nerve regeneration via promoting the histamine H1 receptors on primary neural stem cells in the traumatic brain injury mouse, which suggested the potential of histamine H3 receptor as a promising target for treating neurological disorders and promoting nerve regeneration...

Histamine and H1 receptors play a crucial role in the tumor microenvironment. Preclinical data showed that concomitant use of antihistamines and immune checkpoint inhibitors (ICIs) might increase the effect of ICIs. This study aimed to evaluate the impact of antihistamines on the oncological outcomes of ICIs. This retrospective study was conducted in a tertiary cancer center. Advanced cancer patients treated with ICIs were included in this study. A total of 133 patients receiving ICIs in the metastatic setting were included...

BACKGROUND: By comparing the histamine impact to the instant response to an injected foreign protein in previously sensitized animals, one might hypothesize that histamine may be involved in this reaction. Through all four of the recognized types of histamine receptors, histamine is also essential for the control of immunological function and acute and chronic allergic inflammation. METHODS: Recent evidence points to anti-IgE antibodies and specific antibodies to cytokines like IL-4 or IL-5 that are associated with allergic inflammation as probable causes of Allergic Rhinitis...

The zebrafish (Danio rerio) histamine H1 receptor gene (zfH1 R) was cloned in 2007 and reported to be involved in fish locomotion. Yet, no detailed characterization of its pharmacology and signaling properties have so far been reported. In this study, we pharmacologically characterized the zfH1 R expressed in HEK-293T cells by means of [3 H]-mepyramine binding and G protein-signaling assays. The zfH1 R [dissociation constant (KD ), 0.7 nM] displayed similar affinity for the antagonist [3 H]-mepyramine as the human histamine H1 receptor (hH1 R) (KD , 1...

Histamine receptor-1 (H1 ) antagonists like levocetirizine are frequently used nowadays to treat rhinitis patients who experience rhinorrhea and sneezing. The trachea may be affected by the H1 antagonist when it is used to treat nasal symptoms, either orally or through inhalation. The purpose of this study was to ascertain in vitro effects of levocetirizine on isolated tracheal smooth muscle. As a parasympathetic mimetic, methacholine (10-6 M) causes contractions in tracheal smooth muscle, which is how we tested effectiveness of levocetirizine on isolated rat tracheal smooth muscle...

The cerebellum and its deep nuclei contribute to the regulation of important functions including motor coordination and pain. Histamine modulates some functions of the fastigial nucleus (FN) such as motor coordination. In this study, by application of histamine and activation of its H1 and H2 receptors, the FN processing of visceral pain, general locomotor activity and motor coordination were targeted. The possible mechanism of action was followed by the inhibition of opioid receptors. The right and left sides of the FN were surgically implanted with guide cannulas...

BACKGROUND: Empirical therapy with oral histamine-1 receptor antagonists (H1RAs) is often used for patients with suspected upper airway cough syndrome. No placebo-controlled trials with nonsedating H1RAs (nsH1RAs) have evaluated validated cough outcomes. The objective of the present study was to assess the effect of an nsH1RA, bepotastine, on cough outcomes in patients with allergic rhinitis and persistent cough. METHODS: A randomised, double-blind, placebo-controlled trial was conducted...

PURPOSE: Developing experimental animal models that show clinical symptoms and methods for quantitative and objective evaluation are important for understanding food allergies. Therefore, this study aimed to develop an ovalbumin (OVA)-induced mouse model of food allergy and a useful method to evaluate the symptoms of food allergy. MATERIAL/METHODS: Mice were sensitized via intraperitoneal injection of OVA. Subsequently, local sensitization was performed once weekly by oral administration of OVA...

This review aims to provide a comprehensive overview of the current literature on the drug design, development, and therapy of lurasidone for the treatment of schizophrenia. Lurasidone has antagonistic effects on the dopamine D2 , 5-hydroxytryptamine (5-HT)2A , and 5-HT7 receptors and a partial agonistic effect on the 5-HT1A receptor with low affinities for muscarinic M1 , histamine H1 , and a1 adrenergic receptors. The receptor-binding profile of lurasidone is thought to be associated with fewer side effects such as anticholinergic effects, lipid abnormalities, hyperglycemia, and weight gain...

Meclizine (Antivert, Bonine) is a first-generation H1 antihistamine used in the treatment of motion sickness and vertigo. Despite its wide medical use for over 70 years, its crystal structure and the details of protein-drug interactions remained unknown. In this study, we used microcrystal electron diffraction (MicroED) to determine the three-dimensional (3D) crystal structure of meclizine dihydrochloride directly from a seemingly amorphous powder. Two racemic enantiomers (R/S) were found in the unit cell, which packed as repetitive double layers in the crystal lattice...