[Effect of thyrotropin releasing hormone and its analogs on sleep and wakefulness cycles].

A comparison of the biological activity of the thyreotropin-releasing hormone and its two analogs was carried out as to their ability to stimulate the secretion of thyreothropin from the pituitary body in rats, as well as of their effect on behavioural and electrographic sleep pattern. Among the studied drugs only the thyreotropin-releasing hormone exhibited a clearly pronounced biological activity. Its both analogs were ineffective. The thyreotropin-releasing hormone had a stimulating effect on CNS, slowing down the coming of sleep and shortening its separate phases. Under the influence of the analog A-1 this action was more pronounced. On the contrary, under the influence of the analog A-2 the tendency was toward speeding up the coming of sleep and toward lengthening of its separate episodes. The obtained data suggest a possible discrepancy between biological and neurotropic activity of hypothalamis peptides and the modelling effect of thyreotropin-releasing hormone and some of its analogs on CNS.