• DOI:10.1007/BF00500148
• Corpus ID: 35523412

The physiological disposition of p-octopamine in man

@article{Hengstmann2004ThePD,
  title={The physiological disposition of p-octopamine in man},
  author={J{\"u}rgen H. Hengstmann and Walter Konen and C. Konen and Michel F Eichelbaum and Hans J. Dengler},
  journal={Naunyn-Schmiedeberg's Archives of Pharmacology},
  year={2004},
  volume={283},
  pages={93-106}
}

• J. Hengstmann, W. Konen, +2 authors H. Dengler
• Published 2004
• Biology, Medicine
• Naunyn-Schmiedeberg's Archives of Pharmacology

SummaryAfter oral administration of 3H-p-octopamine (8 mg≙300 μCi) more 3H-activity (93% of the dose) is excreted in the urine within 24 h than after intravenous infusion (2 mg≙300 μCi) over 2.5 h (82% of the dose). This proves that p-octopamine is absorbed quantitatively in man. The absorption proceeds rapidly, peak plasma levels are reached between 30 and 60 min.The only metabolic pathways for p-octopamine are deamination and conjugation. The predominant step is oxidative deamination by monoamine oxidase (MAO) to p-hydroxymandelic acid. This acid represents 2/3 of the urinary 3H-activity after both routes of admistration.A quantitative difference is seen in the fraction of free p-octopamine which equals the amount of conjugated amine after infusion but is only 1/20 after oral administration. This indicates a higher total clearance after an oral dose which consequently explains the diminished efficacy on blood pressure after this route.Hydroxylation to catecholamines was not found.