Role of adrenal catecholamines in cerebrovasodilation evoked from brain stem

Journal Article · Mon Jun 01 04:00:00 EDT 1987 · Am. J. Physiol.: Heart Circ. Physiol.; (United States)

OSTI ID:6145759

Iadecola, C; Lacombe, P M; Underwood, M D; Ishitsuka, T; Reis, D J

The authors studied whether adrenal medullary catecholamines (CAs) contribute to the metabolically linked increase in regional cerebral blood flow (rCBF) elicited by electrical stimulation of the dorsal medullary reticular formation (DMRF). Rats were anesthetized, paralyzed, and artificially ventilated. The DMRF was electrically stimulated with intermittent trains of pulses through microelectrodes stereotaxically implanted. Blood gases were controlled and, during stimulation, arterial pressure was maintained within the autoregulated range for rCBF. rCBF and blood-brain barrier (BBB) permeability were determined in homogenates of brain regions by using (/sup 14/C)iodoantipyrine and ..cap alpha..-aminoisobutyric acid (AIB), respectively, as tracers. Plasma CAs (epinephrine and norepinephrine) were measured radioenzymatically. DMRF stimulation increased rCBF throughout the brain and elevated plasma CAs substantially. Acute bilateral adrenalectomy abolished the increase in plasma epinephrine, reduced the increases in flow in cerebral cortex, and abolished them elsewhere in brain. They conclude that the increases in rCBF elicited from the DMRF has two components, one dependent on, and the other independent of CAs. Since the BBB is impermeable to CAs and DMRF stimulation fails to open the BBB, the results suggest that DMRF stimulations allows, through a mechanism not yet determined, circulating CAs to act on brain and affect brain function.

• Research Organization: Cornell Univ. Medical College, New York, NY (USA)
• OSTI ID: 6145759
• Journal Information: Am. J. Physiol.: Heart Circ. Physiol.; (United States), Journal Name: Am. J. Physiol.: Heart Circ. Physiol.; (United States) Vol. 21:6; ISSN AJPPD
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADRENAL GLANDS
AMINES
AMINO ACIDS
AMINOBUTYRIC ACID
ANIMALS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOCHEMISTRY
BIOELECTRICITY
BLOOD FLOW
BLOOD PRESSURE
BLOOD-BRAIN BARRIER
BODY
BRAIN
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CATECHOLAMINES
CENTRAL NERVOUS SYSTEM
CHEMISTRY
DRUGS
ELECTRICITY
ENDOCRINE GLANDS
GLANDS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MEMBRANE PROTEINS
NERVOUS SYSTEM
NEUROREGULATORS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PERMEABILITY
PHENOLS
PHYSIOLOGY
POLYPHENOLS
PROTEINS
RATS
RECEPTORS
RODENTS
TRACER TECHNIQUES
VASODILATION
VERTEBRATES