Faculty Collaboration Database

Role of medullary lateral reticular formation in baroreflex coronary vasoconstriction. Brain Res 1991 Aug 23;557(1-2):202-9

Date

08/23/1991

Pubmed ID

1660752

DOI

10.1016/0006-8993(91)90135-i

Scopus ID

2-s2.0-0025895905 (requires institutional sign-in at Scopus site)   5 Citations

Abstract

We have recently identified a polysynaptic pathway traversing discrete regions of the hypothalamus, midbrain, and medulla, along which site-specific electrical and chemical activation produces coronary vasoconstriction as part of a sympathoexcitatory response. We tested for the potential functional significance of this pathway by examining the hypothesis that a medullary component is involved in carotid baroreflex induced coronary vasoconstriction. Coronary flow velocity was measured with a Doppler probe in anesthetized cats. Following vagotomy and propranolol, bilateral carotid occlusion produced an increase in mean arterial pressure (56 +/- 14%, means +/- S.E.M.) and in coronary vascular resistance (51 +/- 13%) which was greater than that (29 +/- 6%) expected from the concurrent rise in arterial pressure during aortic constriction. Bilateral microinjections of lidocaine into the medullary lateral reticular formation attenuated the reflex increase in pressure (11 +/- 2%) and virtually abolished the rise (8 +/- 2%) in coronary resistance. After one hour recovery, carotid occlusion again increased aortic pressure (56 +/- 13%) and coronary vascular resistance (47 +/- 15%). Microinjections of lidocaine outside this medullary region did not impair the coronary vasoconstrictor response to carotid occlusion. We conclude that the medullary lateral reticular formation contains neural elements which participate in baroreflex-induced changes in arterial pressure and coronary vascular resistance. Components of the previously described central coronary vasoconstrictor pathway may play a role in pathophysiological conditions associated with increased coronary vasomotor tone.

Author List

Gutterman DD, Arthur JM, Pardubsky PD, Gebhart GF, Marcus ML, Brody MJ

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

Animals
Carotid Stenosis
Cats
Coronary Circulation
Coronary Vessels
Electric Stimulation
Female
Hemodynamics
Lidocaine
Male
Medulla Oblongata
Neural Pathways
Pressoreceptors
Reflex
Reticular Formation
Sympathetic Nervous System
Synaptic Transmission
Vascular Resistance
Vasoconstriction