Phentolamine and isoproterenol: comparison of effects on vascular resistance and oxygen uptake in skeletal muscle during hypotension

Akira Takeshita; Allyn L Mark; Francois M Abboud; Phillip G Schmid; Donald D Heistad; U. James Johannsen

doi:10.1016/S0022-3565(25)30689-0

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Phentolamine and isoproterenol: comparison of effects on vascular resistance and oxygen uptake in skeletal muscle during hypotension

Journal article

Peer reviewed

Phentolamine and isoproterenol: comparison of effects on vascular resistance and oxygen uptake in skeletal muscle during hypotension

Akira Takeshita, Allyn L Mark, Francois M Abboud, Phillip G Schmid, Donald D Heistad and U. James Johannsen

The Journal of pharmacology and experimental therapeutics, Vol.199(2), pp.353-359

11/1976

DOI: 10.1016/S0022-3565(25)30689-0

PMID: 978489

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Abstract

Effects of drugs on precapillary vessels and oxygen uptake may differ from effects on resistance vessels and total flow in skeletal muscle. This study was performed to compare effects of phentolamine and isoproterenol, two drugs which are used to treat shock, on oxygen uptake in skeletal muscle. Oxygen uptake of gracilis muscle (GVO2) was measured in muscles perfused at constant flow or constant pressure in normotensive dogs. We compared effects of the drugs on oxygen uptake at doses chosen so that both drugs produced comparable effects on vascular resistance. With flow constant, phentolamine increased but isoproterenol decreased or did not alter GVO2. With constant pressure, phentolamine produced significantly greater increases in GVO2. For example, increases in GVO2 occurred with all three doses of phentolamine, but only with the high dose of isoproterenol. Neither drug altered oxygen-hemoglobin affinity of red blood cells or oxygen consumption of skeletal muscle in vitro. The results suggest that phentolamine produces more favorable effects than isoproterenol on oxygen uptake in skeletal muscle, presumably because of greater dilator action on precapillary sphincters.

Hemoglobins - metabolism

Phentolamine - pharmacology

Regional Blood Flow

Animals

Hypotension - metabolism

Hypotension - physiopathology

Oxygen Consumption - drug effects

Isoproterenol - pharmacology

Muscles - drug effects

Dogs

Vascular Resistance - drug effects

In Vitro Techniques

Muscles - blood supply

Muscles - metabolism

Details

Title: Subtitle: Phentolamine and isoproterenol: comparison of effects on vascular resistance and oxygen uptake in skeletal muscle during hypotension
Creators: Akira Takeshita
Allyn L Mark
Francois M Abboud
Phillip G Schmid
Donald D Heistad
U. James Johannsen
Resource Type: Journal article
Publication Details: The Journal of pharmacology and experimental therapeutics, Vol.199(2), pp.353-359
Publisher: United States
DOI: 10.1016/S0022-3565(25)30689-0
PMID: 978489
ISSN: 0022-3565
eISSN: 1521-0103
Language: English
Date published: 11/1976
Academic Unit: Molecular Physiology and Biophysics; Cardiovascular Medicine; Fraternal Order of Eagles Diabetes Research Center; Neuroscience and Pharmacology; Internal Medicine
Record Identifier: 9984025329902771

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