γ-Linolenic acid is an ω-6 fatty acid which can be elongated to arachidonic acid for endogenous eicosanoid synthesis. It is a weak LTB4 receptor antagonist, inhibiting [3H]-LTB4 binding to porcine neutrophil membranes with a Ki of 1 μM. γ-Linolenic acid produces 53% inhibition at a 1 mg/kg dose in an in vivo model of LTB4-induced bronchoconstriction.{2361}