[Intranasal application of a thyrotropin-releasing hormone attenuates state-anxiety of the rats]

During the experiments we investigated the influence of thyrotropin-releasing hormone (TRH) on the changes in the behaviour of white rat (Rattus norvegicus) males (n = 90), induced by light uncontrolled impact. After two-week procedure of handling male rats were tested using elevated plus-maze to determine the basal level of anxiety, locomotor and investigative activity and emotionality. A month later we investigated the influence of intranasal administration of TRH-solution (10(-10) M) in a volume of 20 mkl on the anxiety-level increase, induced by stress: short electric foot-shocks. Four hours later animals were tested in the elevated plus-maze. In vehicle-treated animals we detected the increase of anxiety and emotionality level and the decrease of locomotor and investigative activity. In contrast there was no increase of anxiety and emotionality in TRH-treated rats. As to the locomotor and investigative activity, it decreased in TRH-treated animals as well as inthe vehicle-treated. It shows the specific influence on the level of anxiety, which doesn't affect other components of stress-induced behavioral changes Present results suggest TRH as a potential anxiolitic.