Faculty Collaboration Database

Catecholamine-induced changes in vascular capacitance and sympathetic nerve activity in dogs. Can J Physiol Pharmacol 1992 Jul;70(7):1021-31

Date

07/01/1992

Pubmed ID

1451024

DOI

10.1139/y92-141

Scopus ID

2-s2.0-0026482006 (requires institutional sign-in at Scopus site)   8 Citations

Abstract

The effects of three catecholamines, dopamine, epinephrine, and dobutamine, on the systemic circulation, especially on systemic vascular capacitance, were studied using cardiopulmonary bypass in dogs anesthetized with pentobarbital. Venous outflow was divided into three compartments: splanchnic, renal, and other; changes in systemic blood volume (SBV) were calculated from the changes in total venous outflow. To examine the contribution of sympathetic discharge to these vascular responses, sympathetic efferent nerve activity (SENA) from the ventral ansa subclavian nerve was recorded simultaneously. Experiments were done under three conditions: control, after baroreceptor deafferentation, and after hexamethonium injection with low and high doses of each catecholamine. During control and after baroreceptor deafferentation, dopamine- and epinephrine-induced changes in SBV were less than those after hexamethonium, and not significant except with low dose epinephrine. After hexamethonium, dopamine (200 micrograms/kg), epinephrine (10 micrograms/kg), and dobutamine (100 micrograms/kg) reduced SBV by 10.6 +/- 3.4, 13.1 +/- 1.7, and 1.9 +/- 0.3 mL/kg, respectively. Splanchnic outflow increased significantly with dopamine and epinephrine after hexamethonium. High dose dopamine and epinephrine significantly suppressed SENA to 38 +/- 9 and 15 +/- 6% of baseline, respectively. Low dose dopamine decreased arterial pressure and SENA. This suppression in SENA was attenuated but still observed after baroreceptor deafferentation. Dobutamine reduced SBV, but had no effect on SENA. These results suggest that dopamine and epinephrine primarily decrease SBV by venoconstriction in the splanchnic region, however, these effects are greatly modified by basal sympathetic discharge and changes in SENA and vascular tone.

Author List

Arimura H, Bosnjak ZJ, Hoka S, Kampine JP

MESH terms used to index this publication - Major topics in bold

Animals
Blood Pressure
Catecholamines
Dobutamine
Dogs
Dopamine
Epinephrine
Heart Rate
Pressoreceptors
Renal Circulation
Splanchnic Circulation
Sympathetic Nervous System
Vascular Resistance
Vasoconstriction