Kynurenine and pteridines in changes of membrane fluidity.

Abstract

Examination of blood serum lipid and kynurenine content in patients with ischemic heart disease and patients with essential hypertension showed that the elevated whole cholesterol and decreased HDL-cholesterol content were not dependent on kynurenine accumulation in blood. The difference was found out in triglycerol and phospholipid amount. Kynurenine accumulation was followed by an increase of triglycerol and a decrease of phospholipid, especially lecitin amount as well as an increased saturated and decreased unsaturated fatty acid content of phospholipids (Rudzite et al.,1988, 1994). The same changes of lipids were also found in white rats with experimentally induced kynurenine accumulation in blood serum (Rudzite and Jurika, 1991). Moreover, kynurenine addition to incubation medium for phospholipid biosynthesis in vitro was followed by an increase of palmitic and oleic acid, a decrease of linoleic and arachidonic acid incorporation into phospholipids. Further studies showed, that similar deviation in fatty acid incorporation into phospholipids was seen after neopterin addition to incubation medium for phospholipid biosynthesis in vitro. The difference was only in oleic acid incorporation:neopterin decreased, while L-kynurenine increased the oleic acid incorporation into phospholipids (Rudzite et al., 1993,1994).