Tissue distribution of ¹⁴C- and ³⁵S-captopril in rats after intravenous and oral administration

Abstract

1. ³⁵S-Captopril (50mg/kg) administered i.v. to rats resulted in radioactivity being widely distributed into highly vascular tissues and into excretory organs.

2. After oral administration of ¹⁴C-captopril (50mg/kg), radioactivity in most tissues declined at a rate similar to that in blood. Concn. greater than those in blood were found only in kidney, liver and lung. The high concn. of ¹⁴C in kidney and liver were due to the excretory role of these organs. The high concn. of ¹⁴C in lung may be due to the high binding affinity of captopril to angiotensin-converting enzyme, present in large quantity in lung.