In this study, conscious freely behaving rats with functional sympathetic denervation of the vessels, as evidenced by the disappearance of pressor responses to tyramine, did not show any change in the mean level of blood pressure but had a striking increase in the spontaneous MAP (mean arterial pressure) variability as compared with intact rats. This exaggerated blood pressure lability was associated with an increase in the variability of mesentric conductance with no change in that of the hindquarters vascular bed, which is the sum of vascular conductances of all regional hemodynamic changes after sympathectomy and suggest that the sympathetic nervous system may play an important role in reducing short-term hemodynamic variability.
In conclusion, the results of the present study suggest a major role for the sympathetic nervous system in the regulation of regional circulations, the loss of which in sympathectomized rats results in a marked instability of MAP. The vasodilator component of MAP lability after sympathectomy does not appear to depend on an episodic release of NO synthesized by the L-arginine pathway.
Genetic Hypertension, by Jean Sassard
Under the patronage of: Ministère de la recherche et de la technologie, Ministère délégué à la santé, INSERM, CNRS (Départment des sciences de la vie), Conseil général du Rhône, Mairie de Lyon, Chambre de commerce et d'industrie de Lyon
Genetic Hypertension: Proceedings of the 7th International Symposium on SHR and Related Studies Held in Lyon (France), Ecole Normale Supérieure, October 28-30, 1991 = Hypertension Génétique
