Simultaneous Measurement and Recording of Gastric Potential Difference and Intragastric pH in Man

Abstract

Gastric potential difference (GPD) is used increasingly as an index of mucosal integrity. The technique for GPD measurement currently employed is however laborious due to the preparation and check of KCl-agarose bridges prior to each experiment. In addition, calculations – usually handmade – are time-consuming and inaccurate. Therefore, a new apparatus allowing continuous recording of basal and drug-induced changes in GPD values was developed. A commercially available 24-hour pH monitor (Proxima Light®^, Synectics Medical) was modified in order to allow GPD measurement and recording with subsequent elaboration of data. Furthermore, simultaneous measurement of GPD and intragastric pH through the use of a single stomach probe was made possible. The new method was checked towards the classical PD measuring system employing KCl-agarose bridges. The readings obtained with both systems, either in basal conditions or after aspirin, correlated in a highly significant way. Readings proved to be quite stable with a variation, for 150 consecutive values, of less than 2 mV. With this system the effect of pH modifications, obtained through H₂ receptor stimulation and inhibition, on the behaviour of GPD values was investigated in healthy volunteers. Analysis of paired data obtained from these experiments showed an inverse relationship between these two parameters. This suggests that GPD and pH should be measured together, especially during experiments aiming to study drug effects on gastric mucosa. Although the apparatus described was developed for PD measurement and recording in the stomach, it can be used easily for PD measurement across the mucosa of the entire digestive tract, for example in the esophagus, colon or rectum.

Piroxicam-β-Cyclodextrin: A GI Safer Piroxicam

“…Furthermore, a good correlation between the degree of histological damage and changes in GPD has been observed [128]. For these reasons, GPD has been used increasingly as an index of mucosal integrity [130]. …”

Effect of Processed and Non-processed Coffee Samples on Gastric Potential Difference

“…Furthermore, a good correlation between the degree of histological damage and changes of the GPD has been observed [10,11]. In experimental and in humans, GPD data can predict topic irritation of non-steroidal anti-inflammatory drugs and can give information of their acute damaging properties [12]. Therefore, GPD represents a sensitive parameter to monitor the direct pathological effect of a substance on gastric mucosa.…”

Transmucosal Potential Difference as an Index of Esophageal Mucosal Integrity

“…a decrease in its negativity [3,4], We actually found in both animals [15] and humans [ 16] a correlation between the dose of aspirin administered and gastric PD changes ( fig. 4).…”

“…A few years ago, we [ 16] set up a technique for simulta neous measurement of PD and pH by using a single stom ach probe. This probe was nothing but a combined glass electrode modified by replacing the standard internal ref erence wire with polyethylene whiskers which, coming into contact with the mucosa, will also serve as measuring electrode for PD.…”

“…8). By taking as a normal range the mean PD value ± 2 SD obtained from healthy 16] 4 cm above the gastroesophageal junction, and the degree of esophagitis ( fig. 9).…”