Abstract
This paper overviews our early studies on the roles of lysophosphatidic acid (LPA) in soybean lecithin, platelet-activating factor (PAF) in bovine brain lipid extract, and PAF-like phosphatidylcholines having an sn-2 oxidatively shortened fatty acyl group (PAF-like lipids) as a biofactor. Our subsequent important finding is the identification of autotaxin (ATX) as plasma lysophospholipase D which produces LPA in animal biological fluids. Recently, we have obtained evidence that LPA produced by blood cell-associated autotaxin is involved in the induction of pruritus in a mouse model of atopic dermatitis. It has been shown preliminarily that LPA is produced by human oral mucosa cell-bound lysophospholipase D in the oral cavity. We detected LPA in various foods and showed that stress-induced gastric ulcer in rats and aspirin-induced gastric ulcer in mice were protected by administration of LPA into their stomachs. These findings suggest that LPA exerts physiological roles not only as a biofactor but also as a food factor.
