Human Intestinal Amino Acid Absorption and the Role of a Local RAS

Human Intestinal Amino Acid Absorption and the Role of a Local (Renin)-Angiotensin System (RAS)

This study is to find out what role a local intestinal RAS (renin angiotensin system) plays in the context of amino acid absorption in the human intestinal tract and how this RAS and thus the amino acid absorption is influenced by the RAS-active drugs (angiotensin II AT1 receptor blockers (sartans) or ACE inhibitors).

Study Overview

• Status: Completed
• Conditions: Renin-Angiotensin Aldosterone System (RAS)
• Intervention / Treatment: Other: biopsy of intestinal tissue; Other: blood draw; Other: urine collection

• Study Type: Observational
• Enrollment (Actual): 50

Contacts and Locations

Study Locations

• Switzerland
  • Basel, Switzerland, 4031
    • Universitäts-Kinderspital beider Basel (UKBB)
  • Zürich, Switzerland, 8091
    • Universitatsspital Zurich

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Patients undertaking a gastroscopy and / or colonoscopy for a medical indication

Description

Inclusion Criteria:

• Body Mass Index (BMI): 18-35 kg/m2
• cohort 1: therapy with an angiotensin II AT1 antagonist or ACE Inhibitor
• cohort 2: no therapy with an angiotensin II AT1 antagonist or ACE Inhibitor
• Carrying out a diagnostic gastroscopy, colonoscopy or a combined gastroscopy / colonoscopy
• Existence of written consent after detailed information about the study

Exclusion Criteria:

• Severe pathological changes in the gastrointestinal tract (e.g. sprue, stomach ulcers, malignancies); (reflux esophagitis and gastritis are not Exclusion criteria)
• History of gastrointestinal tract surgery (except for appendectomy and inguinal hernia surgery)
• History of malignancy
• Severe acute and chronic organ diseases requiring treatment (e.g. kidney replacement therapy)
• Patients with an increased risk of bleeding (e.g. oral anticoagulation, coagulation disorders)
• Drug or alcohol abuse
• Mental impairment limiting the ability to meet all study requirements

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
RAS- active medication; Patients taking RAS- active medication (ACE- Inhibitor, Angiotensin II AT1 Antagonist (Sartan)) on a daily Basis for at least 6 months for medical reasons	Other: biopsy of intestinal tissue; 4 intestinal tissue biopsies taken from descending Duodenum, 2 intestinal tissue biopsies taken from Ileum, 2 intestinal tissue biopsies taken from ascending colon (additional to routine biopsies taken for gastrointestinal diagnostic); Other: blood draw; 40 ml blood draw (in Heparin blood tubes) (additional to routine blood draw taken for gastrointestinal diagnostic); Other: urine collection; Midstream Urine collection
no RAS- active medication; Patients not taking RAS- active medication	Other: biopsy of intestinal tissue; 4 intestinal tissue biopsies taken from descending Duodenum, 2 intestinal tissue biopsies taken from Ileum, 2 intestinal tissue biopsies taken from ascending colon (additional to routine biopsies taken for gastrointestinal diagnostic); Other: blood draw; 40 ml blood draw (in Heparin blood tubes) (additional to routine blood draw taken for gastrointestinal diagnostic); Other: urine collection; Midstream Urine collection

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
messenger ribonucleic acid (mRNA) quantification in intestinal tissue biopsy	mRNA quantification in intestinal tissue biopsy: mRNA content coding for regulatory RAS protein is measured relative to the mRNA content, which codes for the structural protein villin.	single time-point at baseline
amino acid concentration in blood sample	amino acid concentration in blood sample by High Performance Liquid Chromatography (HPLC)	single time-point at baseline
amino acid concentration in urine sample	amino acid concentration in urine sample by HPLC (High Performance Liquid Chromatography)	single time-point at baseline

Collaborators and Investigators

• Sponsor: University Children's Hospital Basel
• Investigators: Principal Investigator: Raphael N Vuille-dit-Bille, Dr. med., Universitäts-Kinderspital beider Basel (UKBB)

Study record dates

Study Major Dates

• Study Start (ACTUAL): January 27, 2010
• Primary Completion (ACTUAL): May 31, 2011
• Study Completion (ACTUAL): May 31, 2011

Study Registration Dates

• First Submitted: August 19, 2020
• First Submitted That Met QC Criteria: August 19, 2020
• First Posted (ACTUAL): August 24, 2020

Study Record Updates

• Last Update Posted (ACTUAL): August 24, 2020
• Last Update Submitted That Met QC Criteria: August 19, 2020
• Last Verified: August 1, 2020

More Information

Terms related to this study

• Keywords: ACE inhibitors; Angiotensin Converting Enzyme 2 (ACE2); Renin Angiotensin System; Angiotensin II AT1 Receptor Blocker; intestinal amino acid absorption
• Other Study ID Numbers: EK1744; ks20Vuille

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No