Biomaterial Database

Mechanisms for regulation of arterial tone by Ca2+-dependent K+ channels in hypertension. 1996

N J Rusch, and Y Liu, and K A Pleyte

Department of Physiology, Medical College of Wisconsin, Milwaukee 53226, USA.

1. The membrane potential and reactivity of arterial smooth muscle cells is regulated by a variety of K+ channels, which are highly expressed in vascular smooth muscle membranes. 2. Of these K+ channel types, the high-conductance, Ca2+-dependent K+ channel appears to be up-regulated in arterial smooth muscle membranes from hypertensive animals. 3. Patch-clamp studies show that whole-cell membranes and membrane patches of arterial smooth muscle obtained from rats with genetic or renal hypertension show an increased macroscopic and single-channel Ca2+-activated K+ current. Pharmacological block of this K+ current profoundly constricts aortic, renal, mesenteric and femoral arteries obtained from the same hypertensive animals, suggesting that Ca2+-dependent K+ current is a critical determinant of resting membrane potential in arterial muscle exposed to elevated blood pressure. 4. Thus, K+ efflux through Ca2+-dependent K+ channels appears to constitute an important homeostatic mechanism for buffering increases in arterial reactivity in hypertension.

UI	MeSH Term	Description	Entries
D006973	Hypertension	Persistently high systemic arterial BLOOD PRESSURE. Based on multiple readings (BLOOD PRESSURE DETERMINATION), hypertension is currently defined as when SYSTOLIC PRESSURE is consistently greater than 140 mm Hg or when DIASTOLIC PRESSURE is consistently 90 mm Hg or more.	Blood Pressure, High,Blood Pressures, High,High Blood Pressure,High Blood Pressures
D009131	Muscle, Smooth, Vascular	The nonstriated involuntary muscle tissue of blood vessels.	Vascular Smooth Muscle,Muscle, Vascular Smooth,Muscles, Vascular Smooth,Smooth Muscle, Vascular,Smooth Muscles, Vascular,Vascular Smooth Muscles
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002463	Cell Membrane Permeability	A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.	Permeability, Cell Membrane
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001158	Arteries	The vessels carrying blood away from the heart.	Artery
D015221	Potassium Channels	Cell membrane glycoproteins that are selectively permeable to potassium ions. At least eight major groups of K channels exist and they are made up of dozens of different subunits.	Ion Channels, Potassium,Ion Channel, Potassium,Potassium Channel,Potassium Ion Channels,Channel, Potassium,Channel, Potassium Ion,Channels, Potassium,Channels, Potassium Ion,Potassium Ion Channel