Role of the renin-angiotensin system in the regulation of intestinal blood flow and sympathetic neurotransmission
The aims of the present studies were (1) to determine if endogenous angiotensin II (Ang II) plays a role in the local control of mesenteric blood flow (MBF) following volume depletion in anesthetized dogs, and (2) to investigate the mechanism(s) of actions of Ang II on the facilitation of sympathetic neurotransmission in the rate jejunum. To investigate the role of endogenous Ang II in the control of MBF, a dose of an antagonist of Ang II, saralasin, that has effects mainly localized to the mesenteric circulation was determined. The data demonstrated that blockage of actions of Ang II in the mesenteric circulation resulted in a decrease in intestinal vasoconstriction which occurred following acute hypotensive hemorrhage. The effect of Ang II on the uptake and release of norepinephrine from sympathetic nerve endings in the rat jejunum was investigated. The uptake of norepinephrine in rat jejunum was determined by incubating jejunal slices in Krebs buffer containing 0.01 {mu}M {sup 3}H-norepinephrine. The accumulation of label in the tissue after 10 min incubation was determined by liquid scintillation spectrometry. Intracellular uptake of {sup 3}H-norepinephrine was calculated and shown to be an active process.
- Research Organization:
- West Virginia Univ., Morgantown, WV (USA)
- OSTI ID:
- 6367889
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ADRENAL HORMONES
ANGIOTENSIN
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOELECTRICITY
BIOLOGICAL FUNCTIONS
BLOOD FLOW
BODY
CARDIOTONICS
CARDIOVASCULAR AGENTS
DIGESTIVE SYSTEM
DOGS
DRUGS
ELECTRICITY
FUNCTIONS
GASTROINTESTINAL TRACT
GLOBULINS
HEMORRHAGE
HYDROGEN COMPOUNDS
INTESTINES
ISOTOPE APPLICATIONS
MAMMALS
NEUROREGULATORS
NORADRENALINE
ORGANIC COMPOUNDS
ORGANS
PATHOLOGICAL CHANGES
PROTEINS
RATS
RODENTS
SMALL INTESTINE
SYMPATHOMIMETICS
SYMPTOMS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VASOCONSTRICTION
VASOCONSTRICTORS
VERTEBRATES