Phospholipases release arachidonic acid from cell membranes as part of the inflammatory response. Given this information, which type of molecule is derived from arachidonic acid and is involved in this response?

Question

Phospholipases release arachidonic acid from cell membranes as part of the inflammatory response.  Given this information, which type of molecule is derived from arachidonic acid and is involved in this response?

Quizplus · Accepted Answer

11ecba2d_0e61_8764_a3bf_d7dab349ad5e_MD0008_00 Localized inflammatory responses occur near the site of an injury or infection. They frequently involve phospholipase enzymes releasing arachidonic acid from the plasma membranes of affected cells. Arachidonic acid is then modified by cyclooxygenase and a series of other enzymes to form various 20-carbon (eicosanoid), nonhydrolyzable lipids known as prostaglandins. Prostaglandins act as autocrine and paracrine signals (binding to receptors on or near the cell from which they originated). Because they act only on nearby cells, prostaglandins produce a localized inflammatory response. Nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin and ibuprofen treat inflammation by inhibiting prostaglandin synthesis. (Choice A) Terpenes are precursors in the synthesis of cholesterol and steroid hormones. They are derived from isoprenes and do not play a role in inflammatory responses. (Choice B) Ketone bodies are fuel sources that are produced under low glucose conditions. They are derived from acetyl-CoA and are not involved in inflammatory responses. (Choice C) Catecholamines such as epinephrine and norepinephrine are hormones derived from the amino acid tyrosine. They can play a role in inflammatory responses but generally do so as endocrine signals (acting on cells that are distant from their origin). Educational objective: Prostaglandins are nonhydrolyzable, 20-carbon (eicosanoid) lipids involved in autocrine and paracrine signaling. They are derived from arachidonic acid and often help mediate localized inflammatory responses.

Phospholipases Release Arachidonic Acid from Cell Membranes as Part of the Inflammatory