[Effect of serotonin and dopamine on growth of Yersinia pestis and Francisella tularensis strains].

AIM: To study the effects of serotonin and dophamine on the growth of Yersinia pestis and Francisella tularensis strains as well as ability of monoamines to change susceptibility of experimental animals to plague infection.

MATERIALS AND

METHODS

Effect of various doses of biogenic amines on the growth of Y. pestis and F. tularensis was studied by biophotometer "BIO-LOG II" (F ISABIO, France). When studying the effect of amines on LD50 value and mean survival time, serotonin and dophamine were administered to mice peritoneally in dose 25 mg/kg and 100 mg/kg respectively before their inoculation with Y. pestis suspension.

RESULTS

It was shown that one-time addition of serotonin (2.5 - 40.0 mcM) to medium for cultivation of Y. pestis and F. ularensis strains did not significantly affect the bacterial growth both at cultivation temperature 28 degrees C and at 37 degrees C. At the same experimental conditions dophamine stimulated growth of bacterial cultures accelerating the onset of exponential phase of culture growth. Administration of serotonin for 1 hour before inoculation of mice with Y. pestis EV-76 strain increased LD50 value and decreased mean survival time; in contrast, administration of dophamine decreased LD50 value and increased mean survival time.

CONCLUSION

Data on stimulating effect of dophamine on agents of transmissible infections allow to propose that physiological state of an organism as well as medical administration of catecholamines could influence on susceptibility of the host to infection and determine the septic course of the disease.