RELATIONSHIP BETWEEN CHOLESTEROL AND SEROTONERGIC MEASURES IN RATS SUBJECTED TO DIFFERENT STRESSES

The effects of different kinds of acute stress on serum lipids in rela tion to blood serotonergic measures were studied. In rats subjected to electric footshock a fall in total cholesterol, HDL and LDL was found , whereas there was no such change in rats subjected to water-immersio n restraint stress when compared to controls. Serotonin (5-HT) level, a marker of a severity of stress, increased after footshock applicatio n with a concomitant rise in its major metabolite, 5-hydroxyindoleacet ic acid (5-HIAA). This indicates an enhanced 5-HT metabolism. Followin g water-immersion restraint stress 5-HT and 5-HIAA levels did not diff er from controls. Plasma serotonin correlated positively with total ch olesterol in control and restrained rats. In footshocked rats whole bl ood serotonin correlated negatively with total cholesterol. Our data i ndicate that these types of stress may influence serum lipids and peri pheral serotonergic mechanism in different ways.