Activities of proscillaridin A in thoracic duct lymph after single oral doses in man

In order to study the possibility that orally administered proscillaridin after absorption is transported by the lymph to the systemic circulation, the concentrations of the glycoside in thoracic duct lymph were analyzed in two patients with thoracic duct drainage. They received the drug as a single oral dose; plasma and lymph concentrations were measured by 86Rb-technique. Lymph was collected at various intervals for 24 hrs. The proscillaridin activity in thoracic duct lymph was low and followed closely that the plasma. During the sampling period, a total of 300 ng and 240 ng, respectively, was recovered in the lymph, corresponding to less than 0.03% of the administered dose. The results indicate that proscillaridin is not transported by the thoracic duct lymph.