Article
Cardiovascular Differences Between Phenylpropanolamine and Its Related Norephedrine Isomers in the Rat
Journal of Pharmaceutical Sciences
(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, l-NOR and PPA were the most potent compounds at increasing arterial blood pressure, while d-NOR, d-NORP, and l-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 l-NOR and PPA. Repetitive injections of PPA and l-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
- Blood Pressure,
- Phenylpropanolamine,
- Reserpine,
- Optical Rotation
Disciplines
Publication Date
1987
DOI
10.1002/jps.2600760206
Citation Information
Fernando A Moya and P.J. Kiritsy. "Cardiovascular Differences Between Phenylpropanolamine and Its Related Norephedrine Isomers in the Rat" Journal of Pharmaceutical Sciences Vol. 76 Iss. 2 (1987) p. 114 - 116 ISSN: 0022-3549 Available at: http://works.bepress.com/fernando-moya/2/