Article
Cardiovascular Differences Between Phenylpropanolamine and Its Related Norephedrine Isomers in the Rat
Pharmacologist
(1987)
Abstract
Various studies have confused the norephedrine and norpseudoephedrine isomers with phenylpropanolamine (PPA, d,l-norephedrine). This confusion has led us to investigate the pharmacological activity of the norephedrine (NOR) and norpseudoephedrine (NORP) isomers in the cardiovascular system of the urethane:chloralose anesthetized rat. Following intravenous administration, in a cumulative-dose fashion, I-NOR and PPA were the most potent compounds at increasing arterial blood pressure, while d-NOR, d-NORP, and I-NORP were relatively inactive at the doses tested (0.31–10 mg/kg). Prior reserpinization did not significantly shift the cumulative dose-response curves for I-NOR and PPA. Repetitive injections of PPA and I-NOR (1 mg/kg, 4 doses at 5-min intervals) failed to produce tachyphylaxis to the pressor response. On the other hand, when d-NORP was administered in a similar fashion, tachyphylaxis to the second and subsequent doses was observed. These studies demonstrate that significant mechanistic differences exist between these norephedrine isomers.
Keywords
- cardiovascular system
Disciplines
Publication Date
1987
Citation Information
"Cardiovascular Differences Between Phenylpropanolamine and Its Related Norephedrine Isomers in the Rat" Pharmacologist Vol. 76 Iss. 2 (1987) p. 114 - 116 ISSN: 0022-3549 Available at: http://works.bepress.com/fernando-moya/10/