Kallikrein concentrations in the plasma, lymph, thoracic, and cerebrospinal fluid of rabbits

Since there is not an established method for selective assay of kallikrein, it is still unsettled whether kallikrein is absorbed from the intestine or not. Kallikrein was injected into the duodenum of rabbits which had been fasted for 24 hr and the concentrations of the drug in the plasma, lymph and cerebrospinal fluid were determined by an enzymatic method using substrate TAME or Peptide-MCA (hereafter, briefly as TAME method or Peptide-MCA method). An unknown substance, which splits the substrate TAME, appeared in the plasma, lymph and cerebrospinal fluid after injection of kallikrein into the rabbit duodenum. In rabbits which underwent pancreatectomy, kallikrein was not absorbed from the intestine and the unknown substance was not detected in any of the plasma, lymph and cerebrospinal fluid.