The Tse Lab does basic and translational research on the function and regulation of sodium/hydrogen exchange-2 isoform, and molecular biology of nucleoside transporters.

Research in the Sharon Turban Lab focuses on the effects of sodium and potassium on blood pressure and on kidney function. We lead the Chronic Kidney Disease-Potassium (CKD-K) clinical trial, funded by American Heart Association, which examines the benefits and safety of two levels of potassium intake in patients with kidney disease. Other research includes the Chronic Renal Insufficiency Cohort (CRIC) study, which aims to improve the understanding of chronic kidney disease and related cardiovascular illness.

The Lima Lab’s research is concentrated on the development and application of imaging and technology to address scientific and clinical problems involving the heart and vascular system. Specifically, our research is focused on developing magnetic resonance imaging (MRI) contrast techniques to investigate microvascular function in patients and experimental animals with myocardial infarction; functional reserve secondary to dobutamine stimulation and myocardial viability assessed by sodium imaging; and cardiac MRI and computed tomography (CT) program development of techniques to characterize atherosclerosis in humans with cardiovascular or cerebrovascular disease. Current projects include: • The Coronary Artery Risk Development in Young Adults (CARDIA) Study • The MESA (Multi-Ethnic Study of Atherosclerosis) Study • The Coronary Artery Evaluation using 64-row Multidetector Computed Tomography Angiography (CORE64) Study Joao Lima, MD, is a professor of medicine, radiology and epidemiology at the Johns Hopkins School of Medicine.

Secretory diarrhea is a leading cause of childhood morbidity and mortality in developing countries. While diarrhea can be treated with oral rehydration solution (ORS), inclusion of zinc with oral ORS has been shown to reduce the duration of diarrhea. However, how zinc improves diarrhea is not known. It has been shown that zinc acts as an intestinal epithelial cell basolateral potassium channel blocker of cyclic AMP-mediated chloride secretion. We discovered that zinc also stimulates intestinal sodium and water absorption via the epithelial Na/H exchanger, NHE3. Zinc reverses the effect of cyclic AMP inhibition of NHE3 activity. The effect of zinc on NHE3 cannot be duplicated with other divalent metal ions. It has been well established that Na/H exchanger regulatory proteins are involved in NHE3 regulation. Whether these regulatory proteins are involved in zinc stimulation of NHE3 is a focus of our study. Our goal is to reveal mechanisms to explain how zinc improves diarrhea and to understand the role of zinc in salt and water homeostasis in the gut. Our study will provide a scientific basis to justify the inclusion of zinc in ORS for the treatment of secretory diarrhea.