Potassium channels physiological role

Jentsch TJ (2000) Neuronal KCNQ potassium channels physiology and role in disease. Nat Rev Neurosci 1 21-30... 

Nelson MT, Quayle JM 1995 Physiological roles and properties of potassium channels in arterial smooth muscle. Am J Physiol 268 C799—C822... 

The role of calcium in regulating cardiovascular physiology is presented in the fourth section of this volume. House et al. have provided an excellent review on the structure of calmodulin-dependent protein kinase II and its role in the contractility as well as proliferation and migration of VSMC. Banderali et al. have examined in detail the cellular regulation and pharmacological properties of calcium-activated potassium channels and their role in control of vascular tone by endothelium. 

One of the characteristics of protein calcium channels is their sensitivity to ablock by transition metal cations. Lanthanum is a particularly potent blocker. It is suggested that permeant and blocking ions compete for the common binding sites in the channels. The PolyP-PHB channel complexes are also blocked by transition metal cations in a concentration-dependent manner. A nearly complete block of single-channel currents was observed in the synthetic complexes at concentations > 0.1 mM La3+ (0.1 % of Ca2+) (Das et al., 1997). Evidently, PHB-PolyP complexes are versatile ion carriers whose selectivities may be modulated by small adjustments of the local pH. The results may be relevant to the physiological function of PHB-PolyP channels in bacteria and the role of PHBs and PolyPs in the Streptomyces lividans potassium channel (Das and Reusch, 2001). 

This chapter will examine the properties (structure, distribution), pharmacology (openers and blockers as tools to study K+ channels) of calcium and potassium channels. Emphasis will be on integration of the information to develop a picture of the physiological roles of the different types of ion channels. Since potassium channels regulate arterial smooth muscle function by controlling membrane potential, the membrane potential and its relationship to smooth muscle function will be discussed first, as well as the role that K" channels play in controlling membrane potential. 

Hansen SB, TaoX, MacKinnon R (2011) Structural basis of P1P2 activation of the classical inward rectifier channel Kir2.2. Nature (Lond) 477 495 98 Hibino H, Inanobe A, Furutani K, Murakami S, Findlay 1, Karachi Y (2010) Inwardly rectifying potassium channels their structure, function, and physiological roles. Physiol Rev 90 291-366 Ho K, Nichols CG, Lederer WJ, Lytton J, VassUev PM, Kanazirska MV, Hebert SC (1993) Qoning and expression of an inwardly rectifying ATP-regulated potassium channel. Nature (Lond) 362 31-38... 

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