Relationships between pHi and tension in isolated rat mesenteric resistance arteries
| Autor: | J G, Matthews, J E, Graves, L, Poston |
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| Rok vydání: | 1992 |
| Předmět: |
Anions
Sodium-Hydrogen Exchangers Partial Pressure Sodium Rats Inbred Strains Carbon Dioxide Hydrogen-Ion Concentration In Vitro Techniques Ammonium Chloride Mesenteric Arteries Rats Bicarbonates Norepinephrine Vasoconstriction Animals Calcium Vascular Resistance Calcium Channels Carrier Proteins Extracellular Space |
| Zdroj: | Journal of vascular research. 29(4) |
| ISSN: | 1018-1172 |
| Popis: | Investigations into the relationship between pHi and tension were carried out in rat mesenteric resistance arteries. Acute acidosis, induced by ammonium chloride pre-pulse, led to variable and transient tension development, but simultaneous removal of extracellular sodium led to a sustained rise in tension associated with maintained intracellular acidification. Dependence of tension and pHi recovery from acute acidosis on Na/H exchange and anion exchange pathways was demonstrated using pharmacological inhibitors. Additionally, removal of HCO3 suggested the anion pathway involved was Na-dependent HCO3 transport. Removal of extracellular calcium, or pharmacological inhibition of voltage-dependent calcium channels, prevented the tension development in response to NH4Cl pre-pulse in an Na-free medium, but did not affect pHi. Intracellular acidosis resulting from elevation of the PCO2 resulted in initial vasoconstriction followed by profound vasodilatation of arteries pre-contracted with noradrenaline (NA). The response to alkalosis induced by NH4Cl or by lowering the PCO2 led to initial dilatation followed by potentiation of NA-induced tension. |
| Databáze: | OpenAIRE |
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