Arakidonihappoväylä

Arakidonihappoväylä, also known as the arachidonic acid pathway, is a crucial metabolic pathway in biological systems. It begins with the release of arachidonic acid from cell membranes, primarily through the action of phospholipase A2. Arachidonic acid is a polyunsaturated omega-6 fatty acid that serves as a precursor for a variety of signaling molecules.

Once released, arachidonic acid can be metabolized by several enzyme systems. The cyclooxygenase (COX) enzymes, COX-1 and COX-2, convert arachidonic acid into prostaglandins and thromboxanes. Prostaglandins are involved in numerous physiological processes, including inflammation, pain signaling, fever, and blood clotting. Thromboxanes primarily regulate platelet aggregation and vasoconstriction.

Another significant branch of the arachidonic acid pathway involves the lipoxygenase (LOX) enzymes. These enzymes convert arachidonic acid into leukotrienes. Leukotrienes are potent mediators of inflammation, particularly in allergic responses and asthma, where they contribute to bronchoconstriction and mucus secretion.

The products of the arachidonic acid pathway, such as prostaglandins, thromboxanes, and leukotrienes, are collectively known as eicosanoids. These molecules act locally as paracrine or autocrine signaling agents, influencing cellular activity and contributing to complex physiological and pathological processes. Pharmaceutical drugs, such as nonsteroidal anti-inflammatory drugs (NSAIDs), often target enzymes within this pathway to modulate inflammation and pain.