Plasma kinetics of dihydroergotoxin in rat by using a radioreceptor assay.
A radioreceptor assay (RRA) (with brain dopamine receptors) has been developed to determine the levels of dihydroergotoxin-equivalent (DHT-equivalent) material in rat plasma and its kinetics after oral and i.v. administration (5 mg/kg). After i.v. administration the plasma kinetics follows a two-exponential equation, with an apparent distribution volume of 7-9 1/kg and a long half-life (about 36 hours). The kinetics of DHT after oral administration shows two peaks; this could indicate a biliary recycling of the drug and/or of its metabolites. The low bioavailability (19%) and the biliary recycling of DHT-equivalent material suggest a first pass effect.
D000284:Administration, Oral; D000818:Animals; D004088:Dihydroergotoxine / Q000008:administration & dosage / Q000097:blood*; D006207:Half-Life; D007275:Injections, Intravenous; D007700:Kinetics; D008297:Male; D011869:Radioligand Assay; D051381:Rats; D011919:Rats, Inbred Strains
D004088:Dihydroergotoxine