Effect of intraperitoneally injected lysine vasopressin on noradrenaline turnover in certain brain regions of the rat.

In the first part of the study penetration of blood-brain barrier by lysine vasopressin (LVP) was studied. After i.p. injection 125J-LVP or its large fragments appeared in the hypothalamus, hippocampus, tuberculum olfactorium and brain stem. In these structures the effect of i.p. injected LVP on noradrenaline level and turnover rate was studied. LVP produced an increase of noradrenaline level in the hypothalamus, hippocampus and tuberculum olfactorium. In the brain stem no marked changes in noradrenaline content were found. In all the examined brain structures LVP slowed down turnover rate of noradrenaline.