| Abstract: | The effect of the corticoliberin 2-4 fragment--tripeptide Pro-Pro-Ile (PPI) inducing increase in epileptiform activity of mammal on T. molitor males behaviour has been studied. The "open field" method modified for insects has been used. PPI in doses of 30, 60, 100, 1000 micrograms/kg was injected in hemolymph of the beetles. The horizontal activity (HA), number of turns (TN) and other parameters were registered during 6 min. The tripeptide in dose 30 micrograms/kg was non-effective. PPI in doses 100 and, especially, 1000 micrograms/kg evoked stable decrease in HA that was observed as early as 0.5 h after injection. This effect lasted throughout 4-24 hrs and, apparently, induced by nonspecific action of high doses of the peptide. PPI in dose 60 micrograms/kg produced the significant intensification of stressogenic influence of experimental situation: in 2-4 hrs after injection the level of HA and TN increased. It is suggested that PPI can be regarded as an anxiogenic factor of insects. |
