Histamine can be Formed and Degraded in the Human and Mouse Heart.

Histamine is metabolized by several enzymes and . The relevance of this metabolism in the mammalian heart is unclear. However, histamine can exert positive inotropic effects (PIE) and positive chronotropic effects (PCE) in humans via H-histamine receptors.

Design, synthesis, and and characterization of 1-{4-[4-(substituted)piperazin-1-yl]butyl}guanidines and their piperidine analogues as histamine H receptor antagonists.

Previously, we have shown that 1-substituted-[4-(7-phenoxyheptylpiperazin-1-yl)butyl]guanidine with electron withdrawing substituents at position 4 in the benzyl moiety exhibits high affinities toward the guinea pig jejunal histamine H receptor with p ranging from 8.49 to 8.43.

4-Hydroxypiperidines and Their Flexible 3-(Amino)propyloxy Analogues as Non-Imidazole Histamine H₃ Receptor Antagonist: Further Structure⁻Activity Relationship Exploration and In Vitro and In Vivo Pharmacological Evaluation.

Presynaptic histamine H₃ receptors (H₃R) act as auto- or heteroreceptors controlling, respectively, the release of histamine and of other neurotransmitters in the central nervous system (CNS). The extracellular levels of several neurotransmitters are enhanced by H₃R antagonists, and there is a great interest for potent, brain-penetrating H₃ receptor antagonists/inverse agonists to compensate for the neurotransmitter deficits present in various neurological disorders. We have shown that 1-[(benzylfuran-2-yl)methyl]piperidinyl-4-oxyl- and benzyl- derivatives of -propylpentan-1-amines exhibit high in vitro potencies toward the guinea pig H₃ receptor (jejunum), with pA₂ = 8.

Non-Imidazole Histamine H₃ Ligands. Part VII. Synthesis, In Vitro and In Vivo Characterization of 5-Substituted-2-thiazol-4-n-propylpiperazines.

H₃ receptors present on histaminergic and non-histaminergic neurons, act as autoreceptors or heteroreceptors controlling neurotransmitter release and synthesis. Previous, studies have found that the compound -methyl--3-phenylalkyl-2-[2-(4-n-propylpiperazin-1-yl)-1,3-thiazol-5-yl]ethan-1-amine () exhibits high in vitro potency toward H₃ guinea pig jejunal receptors, with pA₂ = 8.27.

Monoaminergic and Histaminergic Strategies and Treatments in Brain Diseases.

The monoaminergic systems are the target of several drugs for the treatment of mood, motor and cognitive disorders as well as neurological conditions. In most cases, advances have occurred through serendipity, except for Parkinson's disease where the pathophysiology led almost immediately to the introduction of dopamine restoring agents. Extensive neuropharmacological studies first showed that the primary target of antipsychotics, antidepressants, and anxiolytic drugs were specific components of the monoaminergic systems.

Monoaminergic Mechanisms in Epilepsy May Offer Innovative Therapeutic Opportunity for Monoaminergic Multi-Target Drugs.

A large body of experimental and clinical evidence has strongly suggested that monoamines play an important role in regulating epileptogenesis, seizure susceptibility, convulsions, and comorbid psychiatric disorders commonly seen in people with epilepsy (PWE). However, neither the relative significance of individual monoamines nor their interaction has yet been fully clarified due to the complexity of these neurotransmitter systems. In addition, epilepsy is diverse, with many different seizure types and epilepsy syndromes, and the role played by monoamines may vary from one condition to another.

Multi-Target Directed Donepezil-Like Ligands for Alzheimer's Disease.

HIGHLIGHTS ASS234 is a MTDL compound containing a moiety from Donepezil and the propargyl group from the PF 9601N, a potent and selective MAO B inhibitor. This compound is the most advanced anti-Alzheimer agent for preclinical studies identified in our laboratory.Derived from ASS234 both multipotent donepezil-indolyl (MTDL-1) and donepezil-pyridyl hybrids (MTDL-2) were designed and evaluated as inhibitors of AChE/BuChE and both MAO isoforms.

Hepatocyte transplants improve liver function and encephalopathy in portacaval shunted rats.

Aim: Rats with portacaval shunt (PCS) are useful experimental models of human hepatic encephalopathy in chronic liver dysfunction. We have previously shown that PCS modifies amine neurotransmitter systems in the CNS and increases voluntary alcohol intake by rats. Hepatocyte transplantation, used in acute liver failure, has recently also been applied to chronic liver diseases, which prompted us to investigate whether the altered brain amine system and the drinking behavior in long-term shunted rats could be normalized by hepatocyte transplants.

Effects of amine oxidases in allergic and histamine-mediated conditions.

This review provides an update on histamine, on diamine oxidase (DAO) and on their implications in allergy and various conditions or affections, such as food histaminosis, ischemia and inflammatory bowel diseases (IBD). The review also presents, in brief, patent coverage on therapies for allergy and IBD with the focus on histamine-related treatments.

Modulation of biogenic amines content by poly(propylene imine) dendrimers in rats.

Biogenic amines and polyamines participate in all vital organism functions, their levels being important function determinants. Studies were performed to check whether repeated administration of poly(propylene imine) (PPI) dendrimers, synthetic macromolecules with diaminobutane core, and peripheral primary amine groups, may influence the endogenous level of amines, as represented by the two of them: spermidine, a natural derivative of diaminobutane, and histamine. The experiment was carried out on Wistar rats.

In vivo toxicity of poly(propyleneimine) dendrimers.

Dendrimers are highly branched macromolecules with the potential to be used for biomedical applications. Several dendrimers are toxic owing to their positively charged surfaces. However, this toxicity can be reduced by coating these peripheral cationic groups with carbohydrate residues.

Histamine in idiopathic inflammatory bowel diseases--not a standby player.

In inflamed bowel there is sustained local secretion of histamine not only from activated mast cells but also from some infiltrating cells. Released histamine acting through different receptors may exert variety of effects. H1 receptors mediate inflammatory effects i.