of, relating to, or of the nature of preference: preferential policies. 2. showing or giving preference: a preferential hiring system. 3. receiving or enjoying preference, as a country in trade relations; favored. Origin of preferential.
Histamine dilates post-capillary venules, activates the endothelium, and increases blood vessel permeability. This leads to local edema (swelling), warmth, redness, and the attraction of other inflammatory cells to the site of release. It also depolarizes nerve endings (leading to itching or pain).
â Histamine is broken down by oxidative deamination by DAO (former name: histaminase) â¢ Decreased Histamine N-Methyl Transferase (HNMT) â Histamine is broken down by ring methylation as a result of histamine-N-methyltransferase (HNMT) Many Systems and Symptoms can be Caused by HIT.