[Degree of vascular tonus as a factor of changes in the reactivity of the smooth muscle structures of the blood vessels].

The activeness and functional orientation of the responses of isolated vascular segments to electric stimulation depends on the initial tonic tension. A relatively low degree of extension of the preparations corresponding to a low intravascular pressure creates a tendency towards a response in the form of relaxation. Stimulations of the same intensity cause contractions against the background of a more significant extension of the preparations observed in cases of high pressure. The constrictive effects occuring against the background of significant vessel extensions are interpreted as a manifestation of inadequate responses, similar to the hyperreactivity noted in hypertension.