title: The fate of infused spermidine in the plasma of rats.
abstract: An elevation of the plasma spermidine concentration might indicate whether administration of a cytostatic drug harms tumour cells. Such elevations, however, are only small. By infusing various amounts of spermidine into the circulation of rats, spermidine plasma elevations were evoked artificially. During 2.5 h infusion and 1.5 h after infusion spermidine plasma concentrations were measured. It appeared that total amounts of 0.031 and 0.4 mg did not give an appreciable elevation of plasma spermidine concentrations above basic levels. Infusion of 1.0 mg gave rise to an elevation but already showed a trend towards normal levels during the infusion. There is evidence for a first-pass lung effect for spermidine. Blocking of monoamine and diamine oxidase enzymes resulted in a further elevation of spermidine concentrations above basic levels. Which of the two enzymes is the more important for spermidine catabolism could not be determined.
mesh_terms: D006631:Amine Oxidase (Copper-Containing) / Q000037:antagonists & inhibitors; D000818:Animals; D003520:Cyclophosphamide / Q000494:pharmacology; D005260:Female; D007263:Infusions, Parenteral; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology; D051381:Rats; D013095:Spermidine / Q000008:administration & dosage / Q000097:blood*; D013997:Time Factors
chemical_list: D008996:Monoamine Oxidase Inhibitors; D003520:Cyclophosphamide; D006631:Amine Oxidase (Copper-Containing); D013095:Spermidine