[Cytophotometric study of the AChE-containing nerve cells and fibers of the rabbit heart after electrostimulation of the area hypothalamica posterior].

By means of cytophotometry and a computer in the cardiac intramural neural plexus of 17 experimental and 17 control rabbits acetilcholine esterase (AChE) activity (revealed by Karnovsky--Roots' method) was investigated. It was stated that a prolonged electrostimulation of the area hypothalamica posterior (AHP) produced statistically significant 2-fold decrease of AChE activity in the cardiac neural cells and fibres. When the stimulation of AHP was stopped, the decreased enzymatic activity was observed for the first two weeks, then by the end of the 4th week it again reached its control level. The results of the work were discussed in view of possible disorders of regulating vegetative-trophic effects of the posterior hypothalamus on innervative and executive tissue elements of the heart.