Summary
This study investigated the effect of acidosis on intracellular pH (pHi), intracellular calcium concentration ([Ca]i), and vascular contraction in the aorta of the newborn and adult rabbit. Isometric tension, pHi, and [Ca]i were measured in an isolated ring preparation. After the vascular contraction was induced with 50 mM KCl, the effect of respiratory acidosis produced by elevation of PCO2 was studied. Respiratory acidosis caused a transient depression followed by a recovery of contractile tension. The decrease in developed tension was greater in the newborn than in the adult. The decrease in pHi during acidosis was similar in the two age groups. [Ca]i increased during acidosis and the increase was greater in the newborn than in the adult. These data show that the vasorelaxant effect of acidosis in the newborn aorta is greater than that in the adult aorta. The greater vasodilation in the newborn cannot be explained by the difference in pHi or [Ca]i.
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References
Wray S (1988) Smooth muscle intracellular pH: Measurement, regulation, and function. Am J Physiol 254:C213–225
Nakanishi T, Okuda H, Nakazawa M, Takao A (1985) Effect of acidosis on contractile function in the newborn rabbit heart. Pediatr Res 19:482–488
Nakanishi T, Seguchi M, Tsuchiya T, Yasukouchi S, Takao A (1990) Effect of acidosis on intracellular pH and Ca concentration in the newborn and adult rabbit myocardium. Circ Res 67:111–123
Nakanishi T, Gu H, Seguchi M, Cragoe EJ, Momma K (1992) HCO −3 -dependent intracellular pH regulation in the premature myocardium. Circ Res 71:1314–1323
Loutzenhiser R, Matsumoto Y, Okawa W, Esptein M (1990) H+-induced vasodilation of rat aorta is mediated by alterations in intracellular calcium sequestration. Circ Res 67:426–439
Rinaldi GJ, Gattaneo A, Gingolani HE (1987) Interaction between calcium and hydrogen ions in canine coronary arteries. J Mol Cell Cardiol 19:773–784
Kontos HA (1981) Regulation of the cerebral circulation. Annu Rev Physiol 43:397–407
Lassen NA (1968) Brain extracellular pH: The main factor controlling cerebral blood flow. Scand J Clin Lab Invest 22:247–251
Irisawa H, Stato R (1986) Intra- and extracellular actions of protons on the calcium current of isolated guinea pig ventricular cells. Circ Res 59:348–3655
Karaki H, Weiss GB (1988) Calcium release in smooth muscle. Life Sci 42:111–122
Ozaki H, Ohyama T, Sato K, Karaki H (1990) Cadependent and independent mechanisms of sustained contraction in vascular smooth muscle of rat aorta. Jpn J Pharmacol 52:509–512
Nakanishi T, Seguchi M, Tsuchiya T, Cragoe EJ Jr, Takao A, Momma K (1991) Effect of partial Na pump and Na-H exchange inhibition on [Ca]i during acidosis in cardiac cells. Am J Physiol 261:C758-C766
Nakanishi T, Gu H, Hagiwara N, Momma K (1993) Mechanisms of oxygen-induced contraction of ductus arteriosus isolated from the fetal rabbit. Circ Res 72:1218–1228
Nakanishi T, Gu H, Momma K (1996) Effect of acidosis on contraction, intracellular pH and calcium in the rabbit mesenteric small artery. J Mol Cell Cardiol 28:1715–1726
Li J, Bukoski RD (1993) Endothelium-dependent relaxation of hypertensive resistance arteries is not impaired under all conditions. Circ Res 72:290–296
Vane JR (1971) Inhibition of prostaglandin synthesis as a mechanism of action for aspirin-like drug. Nature 231:232–235
Rubanyi GM, Vanhoutte PM (1985) Hypoxia releases a vasoconstrictor substance from the canine vascular endothelium. J Physiol 364:45–56
Wallenstein S, Zucker CL, Fleiss JL (1980) Some statistical methods useful in circulation research. Circ Res 27:1–9
Snedecor GW, Cochran WG (1970) Statistical methods. Iowa State University Press, Ames, Iowa
Aalkjaer C, Mulvany MJ (1988) Effect of changes in intracellular pH on the contractility of rat resistance vessels. Prog Biochem Pharmacol 23:150–158
Matthews JG, Graves JE, Poston L (1992) Relationships between pHi and tension in isolated rat mesenteric resistance arteries. J Vasc Res 29:330–340
Jensen PE, Hughes A, Boonen HCM, Aalkjaer C (1993) Force, membrane potential, and [Ca]i during activation of rat mesenteric small arteries with norepinephrine, potassium, aluminum, fluoride, and phorbol ester. Circ Res 73:314–324
Aalkjaer C (1990) Regulation of intracellular pH and its role in vascular smooth muscle function. J Hypertension 8:197–206
West GA, Leppla DC, Simard JM (1992) Effects of external pH on ionic currents in smooth muscle cells from the basilar artery of the guinea pig. Circ Res 71:201–209
Seguchi M, Nakazawa M, Nakanishi T, Kinugawa Y, Takao A (1990) Developmental change of vascular smooth muscle contraction in the rabbit thoracic aorta. Circulation 82:III-491
Nagesetty R, Paul RJ (1994) Effects of pHi on isometric force and [Ca]i in porcine coronary artery smooth muscle. Circ Res 75:990–998
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Nakanishi, T., Gu, H. & Momma, K. Effect of acidosis on contraction, intracellular pH, and calcium in the newborn and adult rabbit aorta. Heart Vessels 12, 207–215 (1997). https://doi.org/10.1007/BF02766785
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DOI: https://doi.org/10.1007/BF02766785