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Titolo:
INFLUENCE OF EXTRACELLULAR PH, SODIUM PROPIONATE AND TRIMETHYLAMINE ON EXCITATION-CONTRACTION COUPLING IN THE RAT TAIL ARTERY
Autore:
ACHIKE FI; BALLARD HJ; OGLE CW;
Indirizzi:
UNIV HONG KONG,FAC MED,DEPT PHYSIOL,5 SASSOON RD HONG KONG HONG KONG UNIV HONG KONG,FAC MED,DEPT PHYSIOL HONG KONG HONG KONG UNIV HONG KONG,FAC MED,DEPT PHARMACOL HONG KONG HONG KONG
Titolo Testata:
Clinical and experimental pharmacology and physiology
fascicolo: 2, volume: 23, anno: 1996,
pagine: 145 - 149
SICI:
0305-1870(1996)23:2<145:IOEPSP>2.0.ZU;2-D
Fonte:
ISI
Lingua:
ENG
Soggetto:
COMPLETE CEREBRAL-ISCHEMIA; SMOOTH-MUSCLE; INTRACELLULAR PH; CARDIOVASCULAR-RESPONSES; BUFFERING POWER; BLOOD-FLOW; WEAK ACIDS; CALCIUM; NOREPINEPHRINE; MECHANISMS;
Keywords:
CALCIUM CHANNELS; PH; VASCULAR CONTRACTILITY;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
23
Recensione:
Indirizzi per estratti:
Citazione:
F.I. Achike et al., "INFLUENCE OF EXTRACELLULAR PH, SODIUM PROPIONATE AND TRIMETHYLAMINE ON EXCITATION-CONTRACTION COUPLING IN THE RAT TAIL ARTERY", Clinical and experimental pharmacology and physiology, 23(2), 1996, pp. 145-149

Abstract

1. The effects of extracellular or intracellular pH changes on agonist- or depolarization-induced contractions of the rat tail artery were investigated, 2. Vessels were perfused initially (25 min) with physiological salt solution (PSS) at a pressure of 30 mmHg. perfusion was then continued with calcium-free PSS containing either 3.0 mu mol/L noradrenaline (NA) or 100 mmol/L K+, which had been made either acidotic oralkalotic, Contractile responses to graded concentrations of calcium were assessed, 3, A reduction in the intracellular or extracellular pHwas induced by the addition of a weak acid (30 mmol/L sodium propionate) or reduction of the concentration of HCO3- in the PSS, respectively; an elevation of the intracellular or extracellular pH was produced by the addition of a weak base (10 mmol/L trimethylamine) or by increasing HCO3-, respectively, The PSS was bubbled with 5% CO2/95% O-2. 4, Lowered intracellular pH did not alter NA- or K+-stimulated contractions. During lowered extracellular pH, contractile responsiveness and peak response were significantly reduced in K+-stimulated arteries, but were not affected in NA-stimulated arteries. 5. Elevated intracellularpH did not alter NA-induced contraction, but reduced the sensitivity to K+-stimulated contractions, Elevated extracellular pH had little effect on the magnitude of K+-induced contractions, but slightly enhanced (although not significantly) NA-induced contractions. 6, It is concluded that reduced contractile responses to K+ during extracellular acidosis are due to the modulation of potential-operated calcium channels(POC), Alkalotic vasodilatation is mediated by intracellular events and is POC-modulated, whereas alkalotic vasoconstriction appears to be due to extracellular events and is modulated by receptor-operated calcium channels (ROC).

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 20/09/20 alle ore 07:41:48