Behavioral conditioning of endotoxin-induced plasma iron alterations

The cascade of physiologic mechanisms in response to infection, the acute-phase response, is recognized as playing a major role in host defence. One such response is the hypoferremia that is consistently reported to occur during bacterial infection. This study aimed to determine whether the alterations in plasma iron were conditionable using the conditioned taste aversion (CTA) paradigm. The regime involved the pairing of a novel-tasting saccharin solution with bacterial endotoxin. Seven days after the initial pairing of these stimuli (the test day), the saccharin solution was represented. Animals exposed to this condition displayed a significant reduction in the level of plasma iron. Animals treated with an intraperitoneal dose of 400 micrograms/Kg lipopolysaccharide (LPS) displayed lower conditioned iron levels than rats infused with 100 micrograms/Kg LPS; however, this difference was not significant. These results showed that in addition to other acute-phase responses (fever and anorexia), plasma iron alterations are able to be manipulated through behavioral manipulations.