Biomaterial Database

Acetylcholine activates a glibenclamide-sensitive K+ current in cat atrial myocytes. 1995

Y G Wang, and S L Lipsius

Department of Physiology, Loyola University of Chicago, Stritch School of Medicine, Maywood, Illinois 60153.

The preceding paper [Y. G. Wang and S. L. Lipsius, Am. J. Physiol. 268 (Heart Circ. Physiol. 37): H1313-H1321, 1995.] showed that when an atrial myocyte is treated with two consecutive exposures to acetylcholine (ACh) separated by a recovery interval, the second ACh exposure elicits a larger increase in K+ conductance than the first ACh exposure. In the present study a nystatin-perforated patch whole cell recording method was used to determine the mechanisms underlying the potentiating effect of ACh on ACh-induced K+ currents and the nature of the potentiated K+ current. The K+ current potentiated by the second ACh exposure was selectively abolished by 1) M1 muscarinic receptor block by 0.1 microM pirenzepine, 2) depletion of sarcoplasmic reticulum (SR) Ca2+ stores by 1 microM ryanodine or 10 mM caffeine, 3) intracellular dialysis with 10 mM ethylene glycolbis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA), 4) omitting external Ca2+, 5) 50% external Na+, 6) inhibition of protein kinase C by 0.01 microM staurosporine or 0.1 microM calphostin C, or 7) inhibition of ATP-sensitive K+ channels with 10 microM glibenclamide (Glib). AFDX-116 (100 microM), an M2 muscarinic receptor antagonist, selectively abolished the conventional ACh-activated K+ current and revealed an ACh-activated Glib-sensitive K+ current. In addition, with K+ conductances blocked and zero external Ca2+, 10 microM ACh induced a small nonselective inward current carried by Na+.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009206	Myocardium	The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.	Muscle, Cardiac,Muscle, Heart,Cardiac Muscle,Myocardia,Cardiac Muscles,Heart Muscle,Heart Muscles,Muscles, Cardiac,Muscles, Heart
D009281	Naphthalenes	Two-ring crystalline hydrocarbons isolated from coal tar. They are used as intermediates in chemical synthesis, as insect repellents, fungicides, lubricants, preservatives, and, formerly, as topical antiseptics.
D010890	Pirenzepine	An antimuscarinic agent that inhibits gastric secretion at lower doses than are required to affect gastrointestinal motility, salivary, central nervous system, cardiovascular, ocular, and urinary function. It promotes the healing of duodenal ulcers and due to its cytoprotective action is beneficial in the prevention of duodenal ulcer recurrence. It also potentiates the effect of other antiulcer agents such as CIMETIDINE and RANITIDINE. It is generally well tolerated by patients.	Gastrotsepin,Gastrozepin,L-S 519,LS-519,Piren-Basan,Pirenzepin,Pirenzepin Von Ct,Pirenzepin-Ratiopharm,Pirenzepine Dihydrochloride,Pyrenzepine,Ulcoprotect,Ulgescum,Dihydrochloride, Pirenzepine,LS 519,LS519,Piren Basan,Pirenzepin Ratiopharm,Von Ct, Pirenzepin
D011083	Polycyclic Compounds	Compounds which contain two or more rings in their structure.	Compounds, Polycyclic
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D011493	Protein Kinase C	An serine-threonine protein kinase that requires the presence of physiological concentrations of CALCIUM and membrane PHOSPHOLIPIDS. The additional presence of DIACYLGLYCEROLS markedly increases its sensitivity to both calcium and phospholipids. The sensitivity of the enzyme can also be increased by PHORBOL ESTERS and it is believed that protein kinase C is the receptor protein of tumor-promoting phorbol esters.	Calcium Phospholipid-Dependent Protein Kinase,Calcium-Activated Phospholipid-Dependent Kinase,PKC Serine-Threonine Kinase,Phospholipid-Sensitive Calcium-Dependent Protein Kinase,Protein Kinase M,Calcium Activated Phospholipid Dependent Kinase,Calcium Phospholipid Dependent Protein Kinase,PKC Serine Threonine Kinase,Phospholipid Sensitive Calcium Dependent Protein Kinase,Phospholipid-Dependent Kinase, Calcium-Activated,Serine-Threonine Kinase, PKC
D011976	Receptors, Muscarinic	One of the two major classes of cholinergic receptors. Muscarinic receptors were originally defined by their preference for MUSCARINE over NICOTINE. There are several subtypes (usually M1, M2, M3....) that are characterized by their cellular actions, pharmacology, and molecular biology.	Muscarinic Acetylcholine Receptors,Muscarinic Receptors,Muscarinic Acetylcholine Receptor,Muscarinic Receptor,Acetylcholine Receptor, Muscarinic,Acetylcholine Receptors, Muscarinic,Receptor, Muscarinic,Receptor, Muscarinic Acetylcholine,Receptors, Muscarinic Acetylcholine
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
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat