Alpha-Adrenoceptor Vascular Function In Chronic Kidney Disease Focus On The Role Of Endothelial Nitric Oxide

Study Summary

The purpose of this study is to learn more about why most patients with early stages of kidney disease have high blood pressure. We know the body produces natural substances that cause blood vessels to open wider to carry more blood when needed. An example is during exercise. Other natural substances cause blood vessels to get smaller and slow down blood flow when needed. An example is when people are cold. The balance between these substances is important. People with kidney disease and high blood pressure do not have the normal balance of these substances. This study will include 3 groups of people, people with normal blood pressure, people with high blood pressure and people with kidney disease. * Subjects will have a screening physical examination, including an ECG and laboratory tests * Subjects with high blood pressure may not take their regular blood pressure medication for 3 weeks prior to the inpatient GCRC study * Subjects will be given intra-arterial medications that will cause changes in the blood vessels during the in-patient study. The study will then compare the responses of the three groups. A GFR test will be done to confirm the renal function of the group with chronic kidney disease. These studies will provide insight into the mechanisms of the pathogenesis of enhanced α1 vasoreactivity in subjects with progressive renal disease. This will lay the groundwork for new strategies in the treatment and prevention of vascular disease among the rapidly growing group of individuals with CKD.

Primary Outcome

Vasoreactivity is defined as Forearm blood flow, dose response curve; ml per minute per log of phenylephrine, or FABF ml/min/logPE; The x axis is the ml/min value and the y axis is the log Phenylephrine concentration.

Interventions

• DRUG Procedure: Regional phenylephrine arterial infusion