Track topics on Twitter Track topics that are important to you
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.
Enhanced adrenergic vascular reactivity may significantly contribute to hypertension and the excessive cardiovascular disease burden in patients with chronic kidney disease (CKD). Nitric oxide (NO), a modulator of neurovascular function, may be linked to adrenergic vascular responsiveness. The central HYPOTHESIS is that the reduction in endothelial nitric oxide (NO) bioavailability contributes to the enhancement of α1-adrenoceptor vasomotor function in patients with CKD.
Specific Aims: In patients with mild to moderate CKD, compared to matched hypertensive and normotensive controls without CKD:
1. Determine if α1-adrenoceptor vasoreactivity is enhanced less by inhibition of endothelial NO
2. Determine whether α1-adrenoceptor vasoreactivity correlates with plasma levels of the endogenous NO inhibitor, asymmetrical dimethylarginine.
Methods: CKD will be confirmed by I125-iothalamate glomerular filtration rate. Regional α1-adrenoceptor vasoreactivity (sensitivity [EC50], reactivity [slope]) will be assessed by venous plethsymography using a graded intra-arterial infusion of the α1-adrenoceptor agonist, phenylephrine. Comparisons of vasoreactivity at baseline and during infusions of L-NMMA will be made between hypertensive non-diabetic subjects with glomerular filtrations rates between 30-70 ml/min age-, gender-, ethnicity- and % body fat-matched hypertensive and normotensive subjects with normal kidney function. In addition, plasma levels of the endogenous NO inhibitor, asymmetric dimethylarginine will be measured in the hypertensive subjects with and without CKD and compared to vasoreactivity.
Significance. These studies will provide insight into the mechanisms of the pathogenesis of enhanced α1 vasoreactivity in subjects with progressive renal disease.
Allocation: Non-Randomized, Control: Placebo Control, Endpoint Classification: Pharmacodynamics Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Educational/Counseling/Training
Chronic Kidney Disease
Procedure: Regional phenylephrine arterial infusion
University of Michigan Hospital
University of Michigan
Published on BioPortfolio: 2014-08-27T03:43:21-0400
The purpose of this study is to determine whether phenylephrine infusion are effective in the prevention of hypotension after changing position to beach chair position during general anest...
the investigators will compare variable infusion of phenylephrine (at a starting rate of 0.75 mcg/Kg/min) with fixed rate (0.75 mcg/Kg/min which will stop of reactive hypertension occurred...
The investigators will compare variable infusion of phenylephrine (at a starting rate of 0.75 mcg/Kg/min) with fixed rate (0.75 mcg/Kg/min which will stop of reactive hypertension occurred...
The study involves research, the purpose of which is to compare three different drug mixtures (Epinephrine, Phenylephrine 25 µg, or Phenylephrine 50 µg). Specifically, how long each med...
Clinical studies evaluating the clinical use of phenylephrine in septic shock are lacking. The present study was designed to compare the effects of norepinephrine and phenylephrine on syst...
Chronic kidney disease is characterized by stiffening, thinning, dilatation, and increased circumferential wall stress of large arteries, associated with increased cardiovascular risk. Kidney transpla...
Pulmonary arterial hypertension (PAH) may lead to right heart failure and subsequently alter glomerular filtration rates (GFR). Chronic kidney disease (CKD, GFR
Both iron deficiency and chronic inflammation are highly prevalent in patients with chronic kidney disease (CKD). The effect of intravenous iron infusion on mineral metabolism in CKD may be modified b...
Arterial stiffness is linked to the progression of atherosclerosis, while activation of vitamin D receptor exerts favorable cardiovascular effects in patients with renal insufficiency. In this study, ...
Evidence indicates a role for dyslipidemia in the development of chronic kidney disease (CKD). However, the association of lipid abnormalities and their ratios with kidney disease using the new CKD Ep...
Regional infusion of drugs via an arterial catheter. Often a pump is used to impel the drug through the catheter. Used in therapy of cancer, upper gastrointestinal hemorrhage, infection, and peripheral vascular disease.
Conditions in which the KIDNEYS perform below the normal level for more than three months. Chronic kidney insufficiency is classified by five stages according to the decline in GLOMERULAR FILTRATION RATE and the degree of kidney damage (as measured by the level of PROTEINURIA). The most severe form is the end-stage renal disease (CHRONIC KIDNEY FAILURE). (Kidney Foundation: Kidney Disease Outcome Quality Initiative, 2002)
The end-stage of CHRONIC RENAL INSUFFICIENCY. It is characterized by the severe irreversible kidney damage (as measured by the level of PROTEINURIA) and the reduction in GLOMERULAR FILTRATION RATE to less than 15 ml per min (Kidney Foundation: Kidney Disease Outcome Quality Initiative, 2002). These patients generally require HEMODIALYSIS or KIDNEY TRANSPLANTATION.
Decalcification of bone or abnormal bone development due to chronic KIDNEY DISEASES, in which 1,25-DIHYDROXYVITAMIN D3 synthesis by the kidneys is impaired, leading to reduced negative feedback on PARATHYROID HORMONE. The resulting SECONDARY HYPERPARATHYROIDISM eventually leads to bone disorders.
Abnormal enlargement or swelling of a KIDNEY due to dilation of the KIDNEY CALICES and the KIDNEY PELVIS. It is often associated with obstruction of the URETER or chronic kidney diseases that prevents normal drainage of urine into the URINARY BLADDER.
Diabetes Diabetes Endocrine Obesity Oxycontin Renal Disease Thyroid Disorders Endocrinology is the study of the endocrine glands and the hormones that they secrete (Oxford Medical Dictionary). There are several groups of h...