Autacoids: Functions and Classes

<p>From dietary histidine by histidine decarboxylase (C)</p> Signup and view all the answers

<p>Histamine (C)</p> Signup and view all the answers

<p>Platelets store serotonin and release it during activation. (A)</p> Signup and view all the answers

<p>Treatment of vomiting disorders. (C)</p> Signup and view all the answers

<p>Diarrhea (C)</p> Signup and view all the answers

<p>Management of allergic reactions. (A)</p> Signup and view all the answers

<p>Regulates GI motility. (C)</p> Signup and view all the answers

<p>It decreases blood pressure by relaxing arterioles. (C)</p> Signup and view all the answers

<p>H2 receptor (B)</p> Signup and view all the answers

<p>First generation H1 antihistamines can easily cross the blood–brain barrier. (A)</p> Signup and view all the answers

<p>Binding of antigenic substances to IgE. (A)</p> Signup and view all the answers

<p>Prevention of motion sickness (C)</p> Signup and view all the answers

<p>Bronchoconstriction and increased mucus secretion. (D)</p> Signup and view all the answers

<p>Sedation (A)</p> Signup and view all the answers

<p>Diphenhydramine (A)</p> Signup and view all the answers

<p>Competitively inhibiting H2-receptors in parietal cells (B)</p> Signup and view all the answers

<p>It activates sensory nerves causing pain and itching. (C)</p> Signup and view all the answers

<p>Uncommon when used as recommended (C)</p> Signup and view all the answers

<p>Stimulation of gastric secretions. (C)</p> Signup and view all the answers

<p>Cromolyn sodium (D)</p> Signup and view all the answers

<p>Increased heart rate (C)</p> Signup and view all the answers

<p>Antagonize histamine's physiological function (A)</p> Signup and view all the answers

<p>Duodenal ulcers (A)</p> Signup and view all the answers

<p>Hydrolyze membrane phospholipids to release arachidonic acid (D)</p> Signup and view all the answers

<p>Vasoconstriction and promoting platelet aggregation (B)</p> Signup and view all the answers

<p>Treating gastric ulceration caused by NSAIDs (C)</p> Signup and view all the answers

<p>Promoting bronchodilation (A)</p> Signup and view all the answers

<p>Inhibit platelet aggregation and cause vasodilatation (B)</p> Signup and view all the answers

<p>Montelukast (Singulair) (A)</p> Signup and view all the answers

<p>Causes bronchoconstriction and asthma (B)</p> Signup and view all the answers

<p>It induces fever (C)</p> Signup and view all the answers

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A class of chemical messengers that act locally, have a short duration of action, and are involved in physiological and pathological processes.

Histamine, serotonin, and angiotensin are examples of autacoids.

Histamine is synthesized from histidine, an amino acid, via an enzymatic reaction.

Mast cells and basophils store and release histamine, which plays a crucial role in allergic reactions.

Histamine released from the stomach lining helps regulate stomach acid secretion.

A chemical compound found in various venoms and insect stings, causing a range of physiological effects.

A process by which histamine is released from cells, often triggered by immune responses, drugs, or physical injury.

A type of histamine receptor that mediates a variety of responses, including smooth muscle contraction, capillary dilation, and vascular permeability.

A type of histamine receptor that primarily regulates gastric acid secretion and other actions.

A type of medication that blocks the effects of histamine by binding to H1 receptors.

An H1 antihistamine that readily crosses the blood-brain barrier, often causing side effects such as drowsiness.

An H1 antihistamine that has less impact on the central nervous system, resulting in fewer sedative side effects.

A group of medications designed to prevent the release of histamine from cells.

A type of antihistamine that blocks histamine from binding to H1 receptors, which are found on various cells throughout the body, including smooth muscle cells, sensory nerves, and blood vessels. This action reduces the symptoms of allergies, such as sneezing, runny nose, and itching.

H1-antihistamines primarily target H1 receptors, which are involved in the allergic response. They work by preventing histamine from binding to these receptors, thus blocking the signaling cascade that leads to allergy symptoms.

H1-antihistamines can cause drowsiness or sedation. This effect is particularly common with first-generation H1-antihistamines. The mechanism involves the inhibition of histamine-induced signaling in the central nervous system.

H2-antihistamines, such as cimetidine and ranitidine, work by competitively blocking histamine from binding to H2 receptors, primarily found in the stomach lining. This action reduces gastric acid production.

Cromolyn sodium inhibits the release of histamine from mast cells, which are immune cells involved in allergic responses. It does not block histamine receptors directly.

Sympathomimetic drugs, such as epinephrine, phenylephrine, and ephedrine, counteract the effects of histamine by activating alpha and beta adrenoceptors. This action increases blood pressure and relaxes bronchi, effectively opposing histamine's effects.

A neurotransmitter synthesized from tryptophan and involved in regulating mood, sleep, appetite, and other bodily functions.

A medication that increases gastrointestinal (GI) motility by stimulating the release of acetylcholine (Ach), a neurotransmitter responsible for muscle contractions.

A type of drug that blocks the effects of serotonin at the 5-HT4 receptors, leading to increased acetylcholine release and improved GI motility.

An antihistamine and 5-HT2 antagonist used to treat various conditions, including feline asthma, hives in horses, and as an appetite stimulant in cats.

A drug that blocks the effects of dopamine at the D2 receptor, used for various conditions including vomiting, reflux, and gastric stasis.

A type of lipid found in cell membranes. It serves as the precursor for arachidonic acid, which is the starting point for the synthesis of eicosanoids.

The enzyme that catalyzes the release of arachidonic acid from membrane phospholipids. This is the first step in the synthesis of eicosanoids.

A polyunsaturated fatty acid released from membrane phospholipids by the action of phospholipase A2. It is the precursor for the synthesis of eicosanoids, including prostaglandins, thromboxanes, and leukotrienes.

An enzyme that catalyzes the conversion of arachidonic acid into prostaglandins and thromboxanes. It is a key enzyme in the synthesis of these eicosanoids.

A group of eicosanoids produced via the cyclooxygenase pathway from arachidonic acid. They have diverse physiological effects. They are involved in processes like inflammation, pain, fever, and blood clotting.

A group of eicosanoids produced via the cyclooxygenase pathway from arachidonic acid. They are primarily involved in platelet aggregation and vasoconstriction. They help in blood clotting and wound healing.

A group of eicosanoids produced via the lipoxygenase pathway from arachidonic acid. These potent mediators of inflammation are primarily associated with allergic reactions, asthma, and inflammation.

Enzyme that catalyzes the conversion of arachidonic acid into leukotrienes in neutrophils, monocytes, macrophages, mast cells, keratinocytes, lungs, spleen, brain, and heart.