ISSN:
1432-2013
Keywords:
Vagus Nerve
;
Cardiac Adaptation
;
Cardiac Denervation
;
Exercise
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Ten dogs were subjected to bilateral removal of thoracic sympathetic chains so as sympathetically to denervate the heart while leaving vagal control intact (so-called Vagal Dogs). Their cardiac output was then estimated at different levels of exercise. The estimation was repeated on eight of these same animals about a year later with almost identical results. Comparing these results with cardiac exercise outputs of seven normal dogs, it emerges that possession of the vagus alone allows normal cardiac response during exercise. Surprisingly, cutting both vagi in these vagal dogs resulted in practically no immediate deterioration of their cardiac response to exercise. These recently vagotomized animals were then contrasted with a group of eight dogs whose hearts had been completely denervated some months previously. The latter had relatively poor cardiac adaptation to exercise. It was concluded that in the sympathectomized dogs even the recent possession of the vagus confers almost full power of cardiac adaptation to exercise. It is suggested that the recent possession of the vagus has trophic influence on the heart enabling it to retain mitochondria essential to normal function.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00587002
Permalink
