Relationship between inhibition of pressor response to angiotensin I and blood concentration of captopril following a single oral administration to dogs.
The time courses for the inhibition of the pressor response to AI and for the blood concentration of captopril and its metabolites were determined following a single oral administration of captopril at a dose of 0.8 or 2.5 mg/kg to normal dogs. Captopril was rapidly absorbed from the gastro-intestinal tract attaining a maximum blood concentration 1-1.5h after its administration. The inhibition of the pressor response to AI was closely related with the blood concentration of unchanged captopril but not of total captopril. The blood concentrations of captopril which produced 50 and 100% inhibition were estimated to be 0.1 and 0.4 millimicron/ml respectively. At 2.5 mh/kg the maximum blood concentration attained was 4 times higher than the concentration required to completely inhibit the pressor response to AI, suggesting that a fraction of the absorbed captopril was in excess of the therapeutic requirement.
D000284:Administration, Oral; D000803:Angiotensin I / Q000037:antagonists & inhibitors*; D000806:Angiotensin-Converting Enzyme Inhibitors; D000809:Angiotensins / Q000037:antagonists & inhibitors*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D002216:Captopril / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology; D004285:Dogs; D008297:Male; D011392:Proline / Q000031:analogs & derivatives*; D013997:Time Factors
D000806:Angiotensin-Converting Enzyme Inhibitors; D000809:Angiotensins; D000803:Angiotensin I; D011392:Proline; D002216:Captopril