Histamine
Histamine - General Information
Histamine stimulates gastric gland secretion, causing an increased secretion of gastric juice of high acidity. This action is probably due mainly to a direct action on parietal and chief gland cells.
Pharmacology of Histamine
Histamine stimulates gastric gland secretion, causing an increased secretion of gastric juice of high acidity. This action is probably due mainly to a direct action on parietal and chief gland cells.
Additional information about Histamine
Histamine Indication: Histamine phosphate is indicated as a diagnostic aid for evaluation of gastric acid secretory function.
Mechanism Of Action: Histamine acts directly on the blood vessels to dilate arteries and capillaries; this action is mediated by both H 1- and H 2-receptors. Capillary dilatation may produce flushing of the face, a decrease in systemic blood pressure, and gastric gland secretion, causing an increased secretion of gastric juice of high acidity. Increased capillary permeability accompanies capillary dilatation, producing an outward passage of plasma protein and fluid into the extracellular spaces, an increase in lymph flow and protein content, and the formation of edema. In addition, histamine has a direct stimulant action on smooth muscle, producing contraction if H 1-receptors are activated, or mostly relaxation if H 2-receptors are activated. Also in humans, the stimulant effect of histamine may cause contraction of the intestinal muscle. However, little effect is noticed on the uterus, bladder, or gallbladder. Histamine has some stimulant effect on duodenal, salivary, pancreatic, bronchial, and lacrimal glands.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Histamine Phosphate
Synonyms: Not Available
Drug Category: Diagnostic aid
Drug Type: Small Molecule; Approved
Other Brand Names containing Histamine Phosphate: Histamine; Histamine biphosphate; Histamine dihydrogen phosphate; Histamine diphosphate;
Absorption: Readily absorbed after parenteral administration
Toxicity (Overdose): LD50=807 mg/kg (mouse, oral). Side effects can lead to hypertension, hypotension, headache, dizziness, nervousness and tachycardia. Large overdoses can lead to seizures.
Protein Binding: Not Available
Biotransformation: Primarily hepatic. Histamine is rapidly metabolized by methylation and oxidation. Methylation involves ring methylation and catalyzation by the enzyme histamine-N-methyltransferase, producing N-methylhistamine, which is mostly converted to N-methyl imidazole acetic acid. 2 to 3% excreted as free histamine, 4 to 8% as N-methylhistamine, 42 to 47% as N-methyl imidazole acetic acid, 9 to 11% as imidazole acetic acid, and 16 to 23% as imidazole acetic acid riboside
Half Life: Not Available
Dosage Forms of Histamine: Liquid Subcutaneous
Solution Topical
Solution Intradermal
Chemical IUPAC Name: 2-(3H-imidazol-4-yl)ethanamine; phosphoric acid
Chemical Formula: C5H15N3O8P2
Histamine Phosphate on Wikipedia: Not Available
Organisms Affected: Humans and other mammals
