MP34-18 IN VITRO STUDY, THE ROLE OF RHO-KINASE IN URETERAL SMOOTH MUSCLE RELAXATION WITH TAMSULOSIN AND TERPENE MIXURE (ROWATINEX¢Ç)

INTRODUCTION AND OBJECTIVES: Animal models have shown that oxalate is both absorbed and secreted within the intestine. Gastrointestinal oxalate absorption has been demonstrated in humans but there are limited data regarding secretion and the conformation of oxalate within the human alimentary tract. The objective of this study was to measure the amount and conformation of oxalate in the stomach and small intestine of adults undergoing upper G.I. endoscopy. METHODS: Eight adults undergoing endoscopy of the stomach or both the stomach and the small bowel participated in this study. None of the patients had end stage renal disease. All fasted for a minimum of 8 hours. Aspirates from fluid and material within these areas were obtained. Oxalate was measured by ion chromatography. The limit of detection of this technique is 1.5 micro-molar. A determination of the soluble and insoluble components of oxalate was made by centrifugation of the sample and subsequent acidification of the resultant pellet. RESULTS: Only one of eight gastric samples had detectable oxalate, 4.9 micro-molar. There was no insoluble oxalate in the gastric samples. In contrast, two of six small intestinal samples contained oxalate, 14.6 micro-molar and 130 micro-molar. All intestinal samples had no insoluble oxalate except the 130 micro-molar specimen, 58 micrograms per gram. CONCLUSIONS: These results demonstrate that there is no measurable oxalate secretion in the stomach in the fasted state in individuals who do not have end stage renal disease. Our results also indicate that in the majority there is no measurable oxalate secretion in the small intestine in the fasted state in subjects without end stage renal disease. While small intestinal oxalate secretion could have occurred in 2 of the subjects, this oxalate could also have emanated from residual food. Further studies are warranted including in patients with renal dysfunction.