Activation of the Serotonergic System Promotes Survival of Different Animal Species Exposed to Bacterial and Chemical Toxins

Abstract

We analyzed the role of serotonergic system in the protection of an organism of different animal species (mice, fish) from lethal doses of bacterial and chemical toxins. In the first series of experiments, peritonitis was induced in mice by i.p. administration of the pathogenic Escherichia coli strain, and the following i.m. administration of the serotonin-modulated anticonsolidation protein (SMAP) significantly increased their survival rate (75 vs. 30%, p < 0.05). In the second series, Western blot analysis showed that i.m. administration of SMAP to mice led after 5 h to a sharp upregulation of the 70 kDa heat shock protein (HSP70) in the liver. In the third series, carried out on the common carp Cyprinus carpio L., i.m. administration of SMAP prior to putting the fish into water containing a high concentration of a systemic insecticide Actara led to the survival of all individuals in the experimental group over the period of 5 days, whereas in the control (SMAP-free) group the survival rate over the same period was only 35% (p < 0.001). In the fourth series, administration of anti-SMAP polyclonal antibodies to C. carpio caused death of 75% of individuals that were put for 5 days into the water containing the sublethal Actara dose, whereas in the intact and control groups all individuals survived under the same conditions (p < 0.001).