prostaglandiini

Prostaglandiini, in Italian usage referring to prostaglandins, are a group of physiologically active lipid compounds known as eicosanoids. They are derived from arachidonic acid and are produced by nearly all body tissues, where they act as local mediators to regulate a wide range of biological processes. Prostaglandins are classified into several families, including prostaglandin E (PGE), D (PGD), F (PGF), I (prostacyclin, PGI), and thromboxane A2 (TXA2), each with multiple subtypes that reflect their tissue-specific roles.

Biosynthesis occurs when phospholipase A2 releases arachidonic acid from membrane phospholipids. Cyclooxygenases (COX-1 and COX-2) convert arachidonic acid to the common intermediate prostaglandin H2 (PGH2), which is then converted by specific synthases into distinct prostaglandins. The biological actions of prostaglandins are mediated mainly through G protein-coupled receptors, designated EP1–EP4 for PGE, DP for PGD, FP for PGF, IP for PGI, and TP for TXA2. The receptors couple to different intracellular signaling pathways, producing diverse, tissue-specific effects.

Physiological and clinical roles of prostaglandins are broad. They participate in inflammation, fever, and pain signaling; regulate vascular tone and permeability; influence platelet aggregation; affect renal blood flow and gastric mucosal protection; and contribute to uterine contractions and cervical ripening during labor. In the lungs, they can cause bronchoconstriction or bronchodilation depending on the receptor profile.

Pharmacologically, prostaglandin synthesis is targeted by NSAIDs, which inhibit COX enzymes and reduce prostaglandin production. Prostaglandin analogs are used therapeutically in obstetrics, ophthalmology, and urology, reflecting the varied actions of these molecules.