PMID: 1566922Apr 11, 1992

Spatial and temporal differing control of sympathetic activities during hemorrhage

The American Journal of Physiology
S KoyamaM Kawamoto


We performed simultaneous multifiber recordings of cardiac, renal (RNA), hepatic (HNA), adrenal, and splenic sympathetic nerve activities during 10 min of sustained hemorrhagic hypotension to a mean blood pressure of 50 mmHg. One minute after bleeding in dogs with intact baroreceptors, all measured nerve activities increased significantly, and a gradual decline toward prebleeding level followed. Only RNA showed a great inhibition below prebleeding level. In cervically vagotomized dogs, all nerve activities showed significantly higher levels than prebleeding control throughout the experiment. The initial increase in HNA observed at 1 min postbleeding in animals with intact baroreceptors was attenuated. HNA in the vagotomized group showed a gradual increase so that 5 min postbleeding, HNA reached a peak level that was maintained until the end of the experiment. Sympathoinhibition in RNA and decrease in heart rate during hemorrhagic hypotension were reversed to significant increases after vagotomy. In contrast, animals with denervation of the carotid sinus and aortic nerves showed initial increases in nerve activities followed by recovery to prebleeding control level within 2 min postbleeding. After complete denervation of systemi...Continue Reading


Sep 20, 2000·American Journal of Physiology. Heart and Circulatory Physiology·S C Malpas, D E Burgess
Aug 16, 2002·American Journal of Physiology. Heart and Circulatory Physiology·Hui XuJames J Galligan
Aug 17, 2001·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·S F Morrison

Related Concepts

Adrenal Glands
Ascending Aorta Structure
Diastolic Blood Pressure
Structure of Carotid Sinus
Canis familiaris
Cardiac Conduction System
Pulse Rate

Related Feeds

Cardiac Conduction System

The cardiac conduction system is a specialized tract of myocardial cells responsible for maintaining normal cardiac rhythm. Discover the latest research on the cardiac conduction system here.