Histamine reaction

Allergic reaction (rash, itching), histamine reaction (decreased BP, increased sweating, flushed face, wheezing)... 

Initial symptoms are those of a histamine reaction and typically occur within 5-90 min of ingestion. Common symptoms include dermal flushing especially of the face, neck, and upper torso, headache, nausea, vomiting, and diarrhea. Facial edema, burning of the mouth and throat, palpitations, dizziness, and rash has also been noted. Bronchospasm, urticaria, shock, and death are rare. Symptoms usually resolve within 3-24 h. 

The intensity of the blue areas on the dissected skin was scored by two independent observers in comparison to standard sets of 5 PCA and histamine reactions with increasing intensity from 0 to 4. The results were expressed in terms of a total score (varying from 0 to 16) obtained by summing the 4 scores for the same reaction type in an individual rat. 

Results in control animals indicated that inhibition of PCA-reactions in compound treated animals was significant on one of the following conditions either a total score below 3, or a difference of more than 8 in comparison to the control rat of the same experimental session. Inhibition of the histamine reactions was significant for a total score below 7, which occurred in 2. 0 % of the control animals. 

The individual intensities of PCA and histamine-induced reactions in rats after oral administration of oxatomide are presented in Fig. 2. A progressive dose-dependent inhibitory effect of oxatomide was obtained on both PCA and histamine reactions. 

Oral ED50 - values (mg/kg, t - 2 h) of various compounds for protection from PCA and histamine reactions... 

In control conditions the median oedema index was 25 (=2. 5mm) for ACF reactions and 20 (= 2. 0 mm) for histamine reactions. On the basis of the distribution of the oedema indices, inhibition of ACF-reactions was significant for values below 14 and of histamine reactions for values below 11. 

Figure 3. Individual oedema indices for Ascaris coeloma fluid (ACF 1 100) and histamine reactions at various times after oral administration of oxatomide in the...

Active doses of oxatomide with respect to ACF-reactions, histamine reactions and Cremophor-induced histamine release are of the same order. It appears therefore likely that the antiallergic activity of oxatomide is the result of two simultaneously occurring actions, a reduction of the amount of mediators set free from sensitized mast cells and an effective antagonism of whatever released histamine is going to act on smooth muscle. 

Senanayake N, Vyravanathan S. Histamine reactions due to ingestion of tuna (Thunnus argentivittatus) in patients antituberculosis themi . Ttxcicon 9Z ) 19,184-5. 

Cold Urticaria (Hives) In some people coldness in tissue causes release of histamine in tissues. The result is itchy, red blotches in the skin. In some cases an exposure produces the same kind of tissue swelling in other area such as breathing passages. Exposure may also produce other histamine reactions, such as vomiting and rapid heart rate. 

There are other forms of lung disorders related to exposures to hazardous materials. Fibrosis is the formation of scar tissue. The tissue forms when the body attempts to engulf foreign material that lodges in the lung. Bronchitis is the overproduction of mucus, which often results in coughing. Asthma is the constriction of the bronchial tubes caused by a histamine reaction to some toxin that produces swelling. Hives on the skin is a similar histamine reaction. 

It is a powerful antagonist of histamine, antagonizing its effect on smooth muscle of the bronchioles, bladder and partially the intestines and preventing the dilation of capillaries. Promethazine is used in the treatment of allergic reactions. 

Among the biochemical reactions that ammo acids undergo is decarboxylation to amines Decarboxylation of histidine for example gives histamine a powerful vasodila tor normally present m tissue and formed m excessive amounts under conditions of trau matic shock... 

Allergic Seasonal or Perennial Rhinoconjunctivitis. Histamine can cause all pathologic features of allergic rhinitis (35—37), with the exception of late-phase inflammatory reactions. Pmritus is caused by stimulation of receptors on sensory nerve endings prostaglandins (qv) may also contribute. Sneering, like pmritus, is an H -mediated neural reflex and can also be mediated by eicosanoids. Mucosal edema, which manifests as nasal... 

Lithium Amide. Lithium amide [7782-89-0], LiNH2, is produced from the reaction of anhydrous ammonia and lithium hydride. The compound can also be prepared by the removal of ammonia from solutions of lithium metal in the presence of catalysts (54). Lithium amide starts to decompose at 320°C and melts at 375°C. Decomposition of the amide above 400°C results first in lithium imide, Li2NH, and eventually in lithium nitride, Li N. Lithium amide is used in the production of antioxidants (qv) and antihistamines (see HiSTAMlNE AND HISTAMINE ANTAGONISTS). 

Histamine. Histamiae [51 -45-6] (200) is an inflammatory autacoid iavolved ia alleigic and anaphylactic reactions (3,39,59) (see... 

L-Tyrosine metabohsm and catecholamine biosynthesis occur largely in the brain, central nervous tissue, and endocrine system, which have large pools of L-ascorbic acid (128). Catecholamine, a neurotransmitter, is the precursor in the formation of dopamine, which is converted to noradrenaline and adrenaline. The precise role of ascorbic acid has not been completely understood. Ascorbic acid has important biochemical functions with various hydroxylase enzymes in steroid, dmg, andhpid metabohsm. The cytochrome P-450 oxidase catalyzes the conversion of cholesterol to bUe acids and the detoxification process of aromatic dmgs and other xenobiotics, eg, carcinogens, poUutants, and pesticides, in the body (129). The effects of L-ascorbic acid on histamine metabohsm related to scurvy and anaphylactic shock have been investigated (130). Another ceUular reaction involving ascorbic acid is the conversion of folate to tetrahydrofolate. Ascorbic acid has many biochemical functions which affect the immune system of the body (131). 

Several methods were reported for the analysis of histamine, but the fluorimetric determination with o-phthaldialdehyde (OPA) the most widely used. It was shown that adducts, formed in the reaction of histamine with OPA in the presence of reducing agent, is more stable and gives high relative fluorescence intensity. The influences of different tiols on the fluorimeric determination histamine with OPA have been investigated. 

Physiological response glycogen breakdown visual excitation histamine secretion in all allergic reactions slowing of pacemaker activity that controls the rate of the heartbeat... 

Note The pre- and post-treatment of the chromatograms with the basic tri-ethylamine solution, which can be replaced by an alcoholic solution of sodium hydroxide [1,4] or a phosphate buffer solution pH = 8.0 (c = 0.2 mol/1) [5], serves to stabilize the fluorescence of the amino derivatives [2]. A final spraying with methanolic hydrochloric acid (chci = 5 mol/1) or 70% perchloric acid renders the detection reaction highly specific for histamine [4] and for catecholamines and indolamines [5]. 

Among the biochemical reactions that anino acids undergo is decarboxylation to fflnines. Decar boxylation of histidine, for example, gives histamine, a powerful vasodilator nonnally present in tissue and fonned in excessive fflnounts under conditions of traumatic shock. 

Etintidine (84), an imidazole-containing histamine H-2 receptor antagonist, is an antiiilcer agent conceptually related to cimetidine and ranitidine. It can be synthesized by various routes one of which terminates by an addition-elimination reaction of propargylamine with substituted N-cyano-S-methylisothiourea derivative 83 to give etintidine (84) [28]. 

Histamine is a biogenic amine that is widely distributed in the body and functions as a major mediator of inflammation and allergic reactions, as a physiological regulator of gastric acid secretion in the stomach, as a neurotransmitter in the central nervous system (CNS) and may also have a role in tissue growth and repair. 

Most GPCRs interact with and activate more than one G-protein subfamily, e.g., with Gs plus Gq/n (histamine H2, parathyroid hormone and calcitonin recqrtors), Gs plus G (luteinising hormone receptor, 32-adrenoceptor) or Gq/11 plus G12/13 (thromboxane A2, angiotensin ATb endothelin ETA receptors). Some receptors show even broader G-protein coupling, e.g., to Gi, Gq/n plus Gi n ( protease-activated receptors, lysophosphatidate and sphingosine-1-phosphate receptors) or even to all four G-protein subfamilies (thyrotropin receptor). This multiple coupling results in multiple signaling via different pathways and in a concerted reaction of the cell to the stimulus. 

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