Eicosanoids, including prostaglandins (PGs) and leukotrienes (LTs) are derived from 20 carbon fatty acids in membrane phospholipids and are important physiological regulators in a variety of systems. While synthesis and actions of eicosanoids are well characterized in mammals, less is known about cellular production and biological actions in poikilothermic vertebrates. As body temperatures in poikilotherms reflect those of the environment, different acclimation states may therefore dramatically affect synthesis and action of eicosanoids. In cannulated bullfrogs, prostaglandins (Herman et al, 1986) and leukotrienes (Herman et al, 1991) have less potent cardiovascular effects in cold-acclimated (5°, 30 days) animals when compared with those at room temperature.KeywordsCold AcclimationAcid Ethyl EsterCarbon Fatty AcidEicosanoid SynthesisRana CatesbeianaThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.