[Effect of chemical sympathectomy on the age dynamics of the heart rate and sensitivity of the heart to adrenaline and acetylcholine].

The guanethidine sympathectomy in 4- and 8-week old white rats increased cardiac sensitivity to acetylcholine. An increase of sensitivity to adrenaline was observed in 8 to 20 weeks of postnatal period. The significance of the changes of extracardiac effects and the cardiac sensitivity to acetylcholine and adrenaline for its chronotropic control in sympathectomized 10-14 week old rats is discussed.