Comparing the Effects of an Immunosuppressant (Mycophenolate Mofetil or MMF) on the Urinary Sodium Excretion Response to Mental Stress in a Crossover Design (MMF)

This study will involve a screening visit and two testing weeks over an approximate 3 week period (this includes a one week "washout" period).

Each testing week will have a 3 day salt-controlled diet prior to testing and an approximate 3-hour testing period on Day 4. The 3-hour testing period will include 10 minutes of a baseline rest, 45 minutes of mild stress (competitive video game), and 45 minutes of a recovery rest. A total of 4 blood and 4 urine samples will be collected during the 3-hour period. Each blood draw will consist of about 7 teaspoons for a total of 28 teaspoons per testing week.

During the screening and testing, I will be asked to take the MoCA (the Montreal Cognitive Assessment) test in order to measure cognitive thinking after stress. It is a brief 30-question test which takes around 10 minutes to complete. It measures different types of cognitive abilities, including orientation (the approximate position of something/someone), short-term memory (remember information for a short period of time), executive function (planning and problem solving), language abilities (assign appropriate names to appropriate items), and visuospatial ability (determine distance from one object to another). Each question is awarded a particular number of points depending on the accuracy of the answers given. We will be looking to see if the total number of points earned changes in response before and after stress.

Screening Visit: I will come to the GPI or the CRU for a screening visit that will last about 90 minutes. The study will be described in detail and an informed consent will be obtained. Vital signs will be taken (blood pressure, height, weight and BMI - Body Mass Index. A health history and a limited physical exam will be conducted by Dr. White (or a physician delegate) to insure that it is safe for me to participate in the study. A blood sample will be obtained from me to make sure nothing is wrong with my kidneys or liver or have any other chronic illness. If all lab work returns with no abnormalities, then I will be cleared to participate in one of the crossover studies.

I will also select my food and drink items from a food menu for the 3-day diet prior to testing. The items I select will give me enough to eat and drink for the 3 days. All food and drink items will be packed in coolers that I will be responsible for picking up and dropping off daily. I am not to eat any food or drink item(s) other than those provided, except for water. To make sure that I am following the diet, I will be asked to return all of my food wrappers and drink containers to the GPI or CRU. I will also be asked to collect an overnight urine sample each night so that they can see how much salt I am taking in each day. My testing weeks will also be scheduled at this visit.