Date of Award

1997

Document Type

Master Thesis

Degree Name

Masters of Science (Research)

Department

Cork Regional Technical College

First Advisor

Dr. John O'Mullane

Second Advisor

Dr. Niall O'Leary

Abstract

The measurement of angiotensin converting enzyme using the substrate FAPGG was investigated with a view to optimising its performance. It was found that a 100 mnol/l triethanolamine-HCl buffer gave a significantly higher absorbance change then the existing TRIS-HCl in the method. As this buffer has not been previously described in the measurement of ACE it was decided to introduce this buffer into a kinetic procedure and evaluate the modified method. The reference interval for the triethanolamine Method was determined by measuring the ACE activity on 200 serum from blood donors and a significant difference (P < 0.05) in the SACE activity of male and female donors was observed.

The modified method was found to correlate well with the existing TRIS CL assay on the Hitachi 704. The purchase by the laboratory of the Hitachi 911 provided an opportunity of running the ACE assay as a kinetic method over a longer incubation period. With the improved performance characteristics of the modified method, the possibility of detecting measurable amounts of ACE in CSF was determined but was found to be too insensitive to measure such low activity..

The potential interference by bilirubin haemoglobin and lipids was investigated. The effect therapeutic ACE inhibitors on the assay was investigated. A dose related response was seen in relation to the ACE inhibitors lisinopril and captopril was seen but inhibition of ACE by captopril was found to decrease on storage at 4°C. A sample would need to be analysed within a few hours in order to give on accurate indication of the degree of inhibition. The potential to use SACE as a bioassay of ACE inhibitors or as a test of compliance is discussed. The millimolar absorptivity of FAPGG on three instruments was evaluated, and compared with calibration as a way of measuring ace activity.

Access Level

info:eu-repo/semantics/openAccess

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