Arachidonic acid is responsible for the smooth muscle-contracting activity of G-acid.
G-acid, a smooth-muscle-contracting substance isolated from human blood plasma, was previously identified as 3-octadecenoic acid. Synthetic cis- and trans-3-octadecenoic acid, however, are biologically inactive. G-acid actually consists of a mixture of fatty acids, characteristic of animal tissues. The biological activity is caused by arachidonic acid, which contracts smooth muscle upon in situ conversion to prostaglandins.
D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology*; D005230:Fatty Acids, Nonesterified / Q000494:pharmacology*; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects / Q000502:physiology*; D009119:Muscle Contraction / Q000187:drug effects*; D010084:Oxidation-Reduction; D011458:Prostaglandins E / Q000494:pharmacology; D011460:Prostaglandins F / Q000494:pharmacology
D001095:Arachidonic Acids; D005230:Fatty Acids, Nonesterified; D011458:Prostaglandins E; D011460:Prostaglandins F