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Titolo:
A GLIBENCLAMIDE-SENSITIVE POTASSIUM CONDUCTANCE IN TERMINAL ARTERIOLES ISOLATED FROM GUINEA-PIG HEART
Autore:
KLIEBER HG; DAUT J;
Indirizzi:
INST NORMALE & PATHOL PHYSIOL,DEUTSCHHAUSSTR 2 D-35033 MARBURG GERMANY TECH UNIV MUNICH,INST PHYSIOL D-80802 MUNICH GERMANY
Titolo Testata:
Cardiovascular Research
fascicolo: 6, volume: 28, anno: 1994,
pagine: 823 - 830
SICI:
0008-6363(1994)28:6<823:AGPCIT>2.0.ZU;2-M
Fonte:
ISI
Lingua:
ENG
Soggetto:
SMOOTH-MUSCLE CELLS; RABBIT PORTAL-VEIN; CORONARY-ARTERY; K+ CHANNELS; CEREBRAL-ARTERIES; CALCIUM CHANNELS; BLOOD-FLOW; CURRENTS; RESISTANCE; ADENOSINE;
Keywords:
CORONARY ARTERIES; K-ATP CHANNEL; GLIBENCLAMIDE; CROMAKALIM;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
46
Recensione:
Indirizzi per estratti:
Citazione:
H.G. Klieber e J. Daut, "A GLIBENCLAMIDE-SENSITIVE POTASSIUM CONDUCTANCE IN TERMINAL ARTERIOLES ISOLATED FROM GUINEA-PIG HEART", Cardiovascular Research, 28(6), 1994, pp. 823-830

Abstract

Objective: The aim was to isolate terminal arterioles from guinea pigheart, to describe their basic electrical properties, and to obtain evidence for the presence of K-ATP channels in microvascular coronary smooth muscle cells. Methods: Terminal arterioles of 20-50 mu m diameter were obtained by enzymatic digestion of isolated perfused hearts. The isolated arterioles were viable for up to 8 h and constricted upon application of high potassium solution. Whole cell clamp experiments onsmooth muscle cells of these arterioles were performed at room temperature. Results: The resting potential of coronary smooth muscle cells in terminal arterioles showed a bimodal distribution with one peak at -23(SD 8) mV and the other peak at -61(4) mV. Application of glibenclamide (50 mu M) to the latter group of arterioles produced a depolarisation to -37(8) mV; application of cromakalim (1 mu M) produced a hyperpolarisation to -71(1) mV The current changes associated with voltage steps and slow voltage ramps in the range -120 to +40 mV indicated that the smooth muscle cells in the arterioles were coupled electrically. The steady state current-voltage relation was sigmoid with a hat region in the range -50 to -30 mV. In the presence of 2-50 mu M glibenclamide the slope resistance at potentials negative to -50 mV and positiveto -30 mV was markedly increased. In the presence of 1 mu M cromakalim the slope resistance was decreased and the current-voltage relation at negative potentials became nearly linear. The crossover point of the current-voltage relations measured under control conditions and in the presence of glibenclamide was near the calculated potassium equilibrium potential. Conclusions: Glibenclamide closes and cromakalim openspotassium channels in smooth muscle cells of coronary arterioles. Thevoltage dependence of the steady state current changes suggests that the current activated by cromakalim is not carried by the same channels as the current inhibited by glibenclamide. The glibenclamide sensitive channels make a significant contribution to the membrane potential of isolated arterioles.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 02/12/20 alle ore 18:17:11