BACKGROUND/AIMS: The functional lumen imaging probe (FLIP) relies on the principle of impedance planimetry that enables direct measurement of intraluminal pressure, cross-sectional areas, and wall biomechanical properties. The aim of our pilot project was to introduce this method to assess function of the lower oesophageal sphincter and pyloric muscle in experimental pigs. METHODS: All measurements were accomplished in one session in six adult female pigs (mean weight 34.2 ± 3.6 kg), using the EndoFLIP 1.0 System with EndoFLIP catheters. Five major parameters were evaluated: balloon pressure (mm Hg), estimated diameter (mm), cross-sectional area (mm2), distensibility (mm2/mm Hg), and zone compliance (mm3/mm Hg). RESULTS: In total, 180 readings were successfully accomplished. Most of the measured values were nearing lower average figures for the lower oesophageal sphincter, and upper average figures for the pylorus in healthy humans. The porcine pyloric sphincter is composed of the Torus pyloricus. It serves as a study "gatekeeper" between the stomach and D1 duodenum, thus explaining higher pyloric readings. There was a clear trend for increasing values of CSA (cross-sectional area), diameter, and balloon pressure with increased filling balloon volumes. However, the sphincter distensibility did not change with increasing filling volumes, either for the lower oesophageal sphincter or pylorus. CONCLUSION: Endoscopic functional luminal planimetry in experimental pigs is feasible, both for the lower oesophageal sphincter and the pylorus. This is an important starting point for future experimental endoscopic trials and pharmacology studies.

• Klíčová slova
• Endoscopic luminal impedance planimetry, Experimental pigs, Lower oesophageal sphincter, Pylorus,
• MeSH
• dolní jícnový svěrač * fyziologie   diagnostické zobrazování   MeSH
• elektrická impedance MeSH
• pilotní projekty MeSH
• prasata MeSH
• pylorus * fyziologie   diagnostické zobrazování   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Background/Objectives: Tacrine is a centrally active non-competitive reversible acetylcholinesterase inhibitor. It also exerts antagonising activity against N-methyl-D-aspartate receptors. Tacrine was approved for the treatment of Alzheimer's disease in 1993, but was withdrawn from clinical use in 2013 because of its hepatotoxicity and gastrointestinal side effects. Nevertheless, tacrine is currently facing a renewed wave of interest primarily due to several new tacrine-incorporated hybrids and derivates. There were two specific aims for this study: firstly, to explain the mechanisms of the adverse action of tacrine, as a distinctive example of a highly effective acetylcholinesterase inhibitor; and secondly to check whether luminal impedance planimetry is feasible for preclinical testing of possible side effects of compounds potentially toxic to the gastrointestinal tract. Methods: Six experimental pigs were used as the animal model in this study. Five major parameters were evaluated: luminal pressure (mmHg), estimated diameter (mm), cross-sectional area (mm2), distensibility (mm2/mmHg), and zone compliance (mm3/mmHg). All measurements were performed before and 360 min after intragastric administration of 200 mg tacrine (at the porcine tacrine Tmax). Results: This study consistently demonstrated an increase in luminal pressure (a directly measured indicator) for the particular balloon filling volumes used, and inversely a reciprocal decrease in the other parameters after tacrine administration. Conclusions: Endoscopic luminal impedance planimetry is a feasible method to evaluate functional response of the lower oesophageal sphincter to tacrine in experimental pigs. Tacrine did not compromise the function of the lower oesophageal sphincter either toward oesophageal spasms or, in contrast, decreased competence of the lower oesophageal sphincter.

• Klíčová slova
• Alzheimer’s disease, endoscopic luminal impedance planimetry, experimental pigs, lower oesophageal sphincter, tacrine,
• Publikační typ
• časopisecké články MeSH