Cell and Neurobiology
Keck School of Medicine
- Membranes & Transport
- Cardiovascular & Skeletal Muscle Diseases
- Diabetes/Metabolic Diseases
Research OverviewThe overall theme of the McDonough lab is to understand the molecular mechanisms responsible for homeostatic control of extracellular Na+, volume, blood pressure and K+, how these are disrupted in disease states and can be corrected therapeutically. Current programs include:
1) Hypertension: Renal sodium transport can provoke hypertension if elevated and compensate for hypertension if decreased. Our current aim is to understand the mechanisms and signals responsible for the changes in sodium transport that occur during hypertension, the molecular mechanisms responsible for the blood pressure lowering effects of anti-hypertensive inhibitors of the renin angiotensin system, and to dissect the molecular mechanisms responsible for renal injury neurogenic dependent hypertension. We pursue these studies in both normotensive and hypertensive animal models applying multi-level strategies from whole animal measures of blood pressure and renal function to biochemical analyses of transporter pool size and subcellular distribution, to confocal and electron microscopy analysis of ion transporter trafficking, to proteomic analyses of transporter associated proteins.
2) Extrarenal mechanisms to regulate K+ homeostasis: The overall aims of this line of investigation are to determine the molecular mechanisms responsible for maintaining extracellular K+ in a narrow range through the concerted regulatory responses of the kidney and muscle. We are interested in determining how kidney rapidly senses and disposes of K+ after a meal, how excess plasma [K+] is cleared into the ICF store in hyperkalemia and during exercise and after K+ restoration, how muscle K+ stores are tapped during hypokalemia, and to understand how these processes are altered in a set of clinically relevant paradigms such as diuretic use and steroid treatment. We have discovered a novel variety of insulin resistance to K+ uptake that occurs during low K+ states, and a novel pathway to clear K+ to the ICF during high K+ states. In addition, we are interested in determining the K+ sensor that sets off regulatory adjustments.