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Histamine is an organic nitrogenous compound involved in local immune responses communication, as well as regulating physiological functions in the gut and acting as ...
Aromatic amino acids often serve as the precursors to important biochemicals. Histidine is the precursor to histamine.; Tryptophan is the precursor to 5-hydroxytryptophan and then serotonin, tryptamine, auxin, kynurenines, and melatonin.
When comparing a polar and nonpolar molecule with similar molar masses, the polar molecule in general has a higher boiling point, because the dipole–dipole interaction between polar molecules results in stronger intermolecular attractions. One common form of polar interaction is the hydrogen bond, which is also
Histidine (symbol His or H) [2] is an essential amino acid that is used in the biosynthesis of proteins.It contains an α-amino group (which is in the protonated –NH 3 + form under biological conditions), a carboxylic acid group (which is in the deprotonated –COO − form under biological conditions), and an imidazole side chain (which is partially protonated), classifying it as a ...
Molecules with a polar surface area of greater than 140 angstroms squared (Å 2) tend to be poor at permeating cell membranes. [1] For molecules to penetrate the blood–brain barrier (and thus act on receptors in the central nervous system), a PSA less than 90 Å 2 is usually needed. [2] TPSA is a valuable tool in drug discovery and development.
Endogenous amines are produced in many different tissues (for example: adrenaline in adrenal medulla or histamine in mast cells and liver). Serotonin, an endogenous amine, is a neurotransmitter derived from the amino acid tryptophan. Serotonin is involved in regulating mood, sleep, appetite, and sexuality. [9]
Histamine is a weak base (a compound able to react with a hydrogen ion to form an acid) that can link with acid groups within the granules of the mast cells. [8] The mechanism of the displacement theory. The crux of this theory lies in the assumption that histamine liberators release histamine by displacing it from cells.
In mammals, histamine is an important biogenic amine with regulatory roles in neurotransmission, gastric acid secretion and immune response. [1] [2] Histidine decarboxylase is the sole member of the histamine synthesis pathway, producing histamine in a one-step reaction. Histamine cannot be generated by any other known enzyme.