Abstract
Isolated rat aorta rings, labelled for 10 min with45Ca in control physiological saline solution (PSS), PSS with 10 μM noradrenaline (NA), or 80 mM potassium-PSS (80 K), were washed out into non-labelled, icecold PSS. NA and 80 K increased tissue45Ca. Retention of stimulated45Ca uptake during washout was studied by subtracting the control washout curve from the washout curves of the stimulated tissues. The measured stimulated uptake fell rapidly during the initial 15 min of washout, thereafter decreasing more slowly. These results suggested that a lengthy wash in icecold PSS would lead to an underestimate of stimulated cellular45Ca uptake. The cellular location of the stimulated uptake was confirmed by using diltiazem (10 μM) and forskolin (10 μM) to block specifically the45Ca influxes caused by 80 K and NA, respectively. A similar biphasic loss of stimulated45Ca uptake was seen in icecold lanthanum (50 mM) solution. These data suggest that established methods for measuring cellular Ca in isolated blood vessels may have markedly underestimated the amount of Ca entering cells during stimulation.
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References
Aaronson P, Jones A (1983) Effects of forskolin and diltiazem on polyionic fluxes in rabbit arterial smooth muscle. Fed Proc 42:898 (abstract)
Aaronson P, van Breemen C (1981) Effects of Na gradient manipulation upon cellular Ca, 45Ca fluxes, and cellular Na in the guinea pig taenia coli. J Physiol 319:443–461
Aaronson P, van Breemen C, Zera P (1982) The loss of NE stimulated Ca uptake during washing of rabbit aorta in icecold La-containing and zero-Ca media. Fed Proc 41:1483 (abstract)
Cauvin C, Loutzenhiser R, van Breemen C (1983) Mechanism of calcium antagonist-induced vasodilation. Annu Rev Pharmacol Toxicol 23:373–396
Deth RC (1978) Effect of lanthanum and reduced temperature on 45Ca efflux from rabbit aorta. Am J Physiol 234(5):C139-C145
Deth R, van Breemen C (1979) Relative contributions of Ca2+ influx and cellular Ca2+ release during drug induced activation of the rat aorta. Pflügers Arch 348:13–22
Godfraind T (1976) Calcium exchange in vascular smooth muscle, action of noradrenaline and lanthanum. J Physiol 260:21–35
Godfraind T, Miller RC (1983) Specificity of action of Ca++ entry blockers: a comparison of their actions in rat arteries and human coronary arteries. Circ Res 52(Suppl I):81–91
Godfraind T, Miller RC, Lima JS (1983) Effects of yohimbine, rauwolscine and corynanthine on contractions and calcium fluxes induced by depolarization and prostaglandin F2α in rat aorta. Br J Pharmacol 80:115–121
Jones AW, Bylund DB, Forte LR (1984) cAMP-dependent reduction in membrane fluxes during relaxation of arterial smooth muscle. Am J Physiol 246:H306-H311
Karaki H, Weiss GB (1979) Alteration in high and low affinity binding of 45Ca in rabbit aortic smooth muscle by norepinephrine and potassium after exposure to lanthanum and low temperature. J Pharmacol Exp Ther 211:86–92
Karaki HY, Weiss GB (1981) Inhibitions of mitochondrial Ca++ uptake dissociated potassium-induced tension responses from increased 45Ca retention in rabbit aortic smooth muscle. Blood Vessels 18:28–35
Keatinge WR (1972) Ca concentration and flux in Ca-deprived arteries. J Physiol 224:35–59
Krejci I, Daniel EE (1970) Effect of contraction on movements of calcium 45 into and out of rat myometrium. Am J Physiol 219(1):256–262
Meisheri K, van Breemen C (1982) Effects of α-adrenergic stimulation on Ca2+ movements in rabbit aortic smooth muscle: relationship with cyclic AMP. J Physiol 331:429–441
Morel N, Godfraind T (1982) Na−Ca exchange in heart and smooth muscle microsomes. Arch Int Pharmacodyn Ther 258: 319–321
Phair R, Hai C (1986) Resolution of intracellular calcium metabolism in intact segments of rabbit aorta. Circ Res 59:74–84
Schatzmann H, Vincenzi F (1969) Calcium movements across the membrane of human red cells. J Physiol 201:369–395
van Breemen C, Farinas FR, Gerba P, McNaughton ED (1972) Excitation-contraction coupling in rabbit aorta studied by the lanthanum method for measuring cellular Ca influx. Circ Res 30:44–54
van Breemen C, Hwang O, Siegel B (1977) The lanthanum method. In: Casteels R, Godfraind T, Ruegg J (eds) Excitation-contraction coupling in smooth muscle. Elsevier/North Holland, Amsterdam, p 242
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Aaronson, P.I. Estimation of high K- and noradrenaline-induced45Ca uptakes in isolated rat aorta: effects of washing in icecold solutions. Pflugers Arch. 414, 579–583 (1989). https://doi.org/10.1007/BF00580994
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DOI: https://doi.org/10.1007/BF00580994