Clinical trial NCT01252368: Human Intestinal Amino Acid Absorption and the Role of a Local (Renin)-Angiotensin System (RAS)
Official title: Human Intestinal Amino Acid Absorption and the Role of a Local (Renin)-Angiotensin System (RAS)
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Healthy Participants
Hypertension
Lead sponsor: University of Zurich
Sponsor class: OTHER
First posted: 2010-12-03
Enrollment: 48
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: Patients attending the hospital for clarification of gastrointestinal symptoms by gastroduodenoscopy or colonoscopy

Brief summary: Aim of this trial is to investigate the expression and localisation of different amino acid transporters and their regulatory proteins derived from the regulatory proteins of the local renin angiotensin system (RAS) in the intestine. This is investigated on one hand in patients who do not take any drugs interfering with RAS. On the other hand expression analysis is done in patients taking daily RAS-active drugs, like ACE inhibitors or sartanes.

After obtaining informed consent of patients attending the hospital for clarification of gastrointestinal symptoms by gastroduodenoscopy or colonoscopy, 2 biopsies (in addition to biopsies needed for clinical diagnostics) will be taken from each duodenum, jejunum, ileum and descending colon.

Biopsies are investigated anonymously at the Institute of Physiology of the University of Zurich. The mRNA content of amino acid transporters and regulatory proteins, respectively, in the biopsies is analyzed by quantitative PCR. Transport proteins are in addition analyzed with immunohistochemistry.

Furthermore amino acid concentration in plasma and urine samples are analyzed by HPLC. From plasma and serum samples RAS parameters like renin, aldosterone, ACE and angiotensin(1-7) are measured.


Eligibility criteria: Inclusion criteria:

* Men and women aged 18-80 years
* BMI 18-35 kg/m2
* Group 1: patients taking daily RAS-active drugs, like ACE inhibitors or sartanes (treatment indication outside of this study)
* Group 2: no therapy with RAS-active drugs, like ACE inhibitors or sartanes Gastroduodenoscopy and/or colonoscopy with a treatment indication outside of this study
* Informed consent

Exclusion criteria:

* Severe pathologic alterations in the gastrointestinal tract (ulcers, tumors, celiac disease; GERD and gastritis are no exclusion criteria)
* Status after operations of the gastrointestinal tract (except uncomplicated appendectomy or inguinal hernia repair)
* Patients with malignant diseases
* Severe acute or chronic diseases which require treatment (e.g. renal replacement therapy)
* Patients with increased bleeding risk (e.g. oral anticoagulation, coagulopathy)
* Drug or alcohol abuse
* Mental disorders which limits the ability to fulfil all study requirements

Primary outcomes:
Secondary outcomes:
Other outcomes:
Locations:
city: Zurich
country: Switzerland
facility: University Hospital Zurich, Gastroenterology and Hepatology
state: ZH
Study officials:
affiliation: University Hospital Zurich, Gastroenterology and Hepatology
name: Werner Schwizer, Professor MD
role: PRINCIPAL_INVESTIGATOR
References: