Investigating pancreatic α-amylase in gastric juice

Abstract

The aims of the study were to develop a method that quantitatively measures P-AM in gastric juice; to differentiate between P-AM and S-AM in gastric juice; to investigate the effect of pH, temperature and time on P-AM detection in gastric juice; to qualitatively analyse P-AM in gastric juice; to investigate the effect of PPI treatment on P-AM.

P-AM and AMYL activities were measured at room temperature and on ice. A P-AM pH curve was obtained by testing P-AM activity at different pH values. Different buffer to gastric juice ratio were used to measure P-AM and AMYL activities for an optimum ratio. P-AM and AMYL activities were assayed using the Reflotron® and Phadebas® Amylase test and calibration curves were obtained. Gastric juice from thirteen patient samples on PPT treatment and from four controls was tested for P-AM activity. There was a significant difference between P-AM activity at different time intervals with a P-value of 0.00679 (P<0.05). There was no significant difference between the effect of temperature and time with a P-value of 0.384 (P>0.05). The P-AM calibration curves show lower measured P-AM activity than standard values. A significant correlation was noted with a correlation co-efficient of 0.9998 (P<0.05) using the Reflotron ®.

The Reflotron® and the Phadebas® Amylase test can quantitatively analyse P-AM and AMYL activities in gastric juice whereas Iso-Electrofocusing can be used for qualitative analysis. The Hitachi 917 quantitatively analysed AMYL activity and the Agarose method quantitatively analysed P-AM activity in gastric juice. Denaturing of P-AM occurs at a pH < 4.00 and> 10.00. The optimum buffer to gastric juice ratio is 55:45. The time taken from collection to analysis of P-AM activity is critical using the Reflotron® which is not influenced by storage temperature. Hyperamylasemia was present in gastric juice of patients on PPI treatment. No P-AM was found present in the four controls.