Abstract
1. Intracellular pH (pHi) was recorded in single, isolated guinea-pig ventricular myocytes using the pH-sensitive fluorophore, carboxy-SNARF-1 (AM-loaded). 2. The dual acid extrusion system in this cell (Na(+)-H+ antiport and Na(+)-HCO3- symport) was activated by inducing an intracellular acid load, produced by addition and subsequent removal of extracellular 10 mM NH4Cl. Under these conditions, it is known that both acid-equivalent extruders are activated about equally. 3. Application of phenylephrine (100 microM; alpha-adrenergic agonist) resulted in an inhibition of pHi recovery from an acid load, recorded in HCO3-buffered medium containing 1.5 mM amiloride (amiloride inhibits Na(+)-H+ antiport; under these conditions pHi recovery is mediated through only the Na(+)-HCO3- symport carrier). This inhibitory effect of phenylephrine was prevented by the alpha 1-antagonist, prazosin (0.1 microM) and was unaffected by propranolol (1 microM). 4. Application of phenylephrine in Hepes-buffered medium (only Na(+)-H+ antiport is active under these conditions) elicited a stimulation of pHi recovery, again prevented by prazosin (0.1 microM). 5. These results point to an alpha 1 inhibition of Na(+)-HCO3- symport and an alpha 1 stimulation of Na+-H+ antiport. 6. Both adrenaline (1-5 microM) and noradrenaline (5 microM) slowed pHi recovery recorded in HCO3(-)-buffered solution containing amiloride (1.5 mM). The similarity of this result with that obtained previously using phenylephrine (paragraph 3) suggests that all three agonists inhibit the Na(+)-HCO3- symport through alpha 1 activation. 7. Isoprenaline (1 microM; beta-adrenergic agonist) slowed pHi recovery in Hepes-buffered solution but stimulated recovery in a HCO3(-)-buffered solution containing amiloride (1.5 mM). These results suggest that beta activation slows Na(+)-H+ antiport but stimulates Na(+)-HCO3- symport. 8. When both acid-equivalent extrusion carriers were inhibited in Na(+)-free, HCO3(-)-buffered medium, phenylephrine or isoprenaline had no effect on pHi, ruling out any effect of the adrenergic agonists on background acid-loading mechanisms. 9. Under physiological conditions (CO2/HCO3(-)-buffered solution, no amiloride), when both acid extruders would be activated by an intracellular acid load, application of phenylephrine, adrenaline or noradrenaline were found to slow pHi recovery. In contrast, isoprenaline stimulated pHi recovery under the same conditions.(ABSTRACT TRUNCATED AT 400 WORDS)
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Selected References
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- Benos D. J. Amiloride: a molecular probe of sodium transport in tissues and cells. Am J Physiol. 1982 Mar;242(3):C131–C145. doi: 10.1152/ajpcell.1982.242.3.C131. [DOI] [PubMed] [Google Scholar]
- Bountra C., Kaila K., Vaughan-Jones R. D. Mechanism of rate-dependent pH changes in the sheep cardiac Purkinje fibre. J Physiol. 1988 Dec;406:483–501. doi: 10.1113/jphysiol.1988.sp017392. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bountra C., Vaughan-Jones R. D. Effect of intracellular and extracellular pH on contraction in isolated, mammalian cardiac muscle. J Physiol. 1989 Nov;418:163–187. doi: 10.1113/jphysiol.1989.sp017833. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Boyarsky G., Ganz M. B., Cragoe E. J., Jr, Boron W. F. Intracellular-pH dependence of Na-H exchange and acid loading in quiescent and arginine vasopressin-activated mesangial cells. Proc Natl Acad Sci U S A. 1990 Aug;87(15):5921–5924. doi: 10.1073/pnas.87.15.5921. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brückner R., Mügge A., Scholz H. Existence and functional role of alpha 1-adrenoceptors in the mammalian heart. J Mol Cell Cardiol. 1985 Jul;17(7):639–645. doi: 10.1016/s0022-2828(85)80063-8. [DOI] [PubMed] [Google Scholar]
- Buckler K. J., Vaughan-Jones R. D. Application of a new pH-sensitive fluoroprobe (carboxy-SNARF-1) for intracellular pH measurement in small, isolated cells. Pflugers Arch. 1990 Oct;417(2):234–239. doi: 10.1007/BF00370705. [DOI] [PubMed] [Google Scholar]
- Burnstock G., Kennedy C. A dual function for adenosine 5'-triphosphate in the regulation of vascular tone. Excitatory cotransmitter with noradrenaline from perivascular nerves and locally released inhibitory intravascular agent. Circ Res. 1986 Mar;58(3):319–330. doi: 10.1161/01.res.58.3.319. [DOI] [PubMed] [Google Scholar]
- Burnstock G. Review lecture. Neurotransmitters and trophic factors in the autonomic nervous system. J Physiol. 1981;313:1–35. doi: 10.1113/jphysiol.1981.sp013648. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cohen I. S., Datyner N. B., Gintant G. A., Mulrine N. K., Pennefather P. Properties of an electrogenic sodium-potassium pump in isolated canine Purkinje myocytes. J Physiol. 1987 Feb;383:251–267. doi: 10.1113/jphysiol.1987.sp016407. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dart C., Vaughan-Jones R. D. Na(+)-HCO3- symport in the sheep cardiac Purkinje fibre. J Physiol. 1992;451:365–385. doi: 10.1113/jphysiol.1992.sp019169. [DOI] [PMC free article] [PubMed] [Google Scholar]
- De Young M. B., Scarpa A. Extracellular ATP induces Ca2+ transients in cardiac myocytes which are potentiated by norepinephrine. FEBS Lett. 1987 Oct 19;223(1):53–58. doi: 10.1016/0014-5793(87)80508-2. [DOI] [PubMed] [Google Scholar]
- Eisner D. A., Lederer W. J., Vaughan-Jones R. D. The dependence of sodium pumping and tension on intracellular sodium activity in voltage-clamped sheep Purkinje fibres. J Physiol. 1981 Aug;317:163–187. doi: 10.1113/jphysiol.1981.sp013819. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fabiato A., Fabiato F. Effects of pH on the myofilaments and the sarcoplasmic reticulum of skinned cells from cardiace and skeletal muscles. J Physiol. 1978 Mar;276:233–255. doi: 10.1113/jphysiol.1978.sp012231. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fliegel L., Walsh M. P., Singh D., Wong C., Barr A. Phosphorylation of the C-terminal domain of the Na+/H+ exchanger by Ca2+/calmodulin-dependent protein kinase II. Biochem J. 1992 Feb 15;282(Pt 1):139–145. doi: 10.1042/bj2820139. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gordon J. L. Extracellular ATP: effects, sources and fate. Biochem J. 1986 Jan 15;233(2):309–319. doi: 10.1042/bj2330309. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hescheler J., Nawrath H., Tang M., Trautwein W. Adrenoceptor-mediated changes of excitation and contraction in ventricular heart muscle from guinea-pigs and rabbits. J Physiol. 1988 Mar;397:657–670. doi: 10.1113/jphysiol.1988.sp017024. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Iwakura K., Hori M., Watanabe Y., Kitabatake A., Cragoe E. J., Jr, Yoshida H., Kamada T. Alpha 1-adrenoceptor stimulation increases intracellular pH and Ca2+ in cardiomyocytes through Na+/H+ and Na+/Ca2+ exchange. Eur J Pharmacol. 1990 Sep 4;186(1):29–40. doi: 10.1016/0014-2999(90)94057-5. [DOI] [PubMed] [Google Scholar]
- Kaila K., Vaughan-Jones R. D. Influence of sodium-hydrogen exchange on intracellular pH, sodium and tension in sheep cardiac Purkinje fibres. J Physiol. 1987 Sep;390:93–118. doi: 10.1113/jphysiol.1987.sp016688. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Karliner J. S., Barnes P., Hamilton C. A., Dollery C. T. alpha 1-Adrenergic receptors in guinea pig myocardium: identification by binding of a new radioligand, (3H)-prazosin. Biochem Biophys Res Commun. 1979 Sep 12;90(1):142–149. doi: 10.1016/0006-291x(79)91601-2. [DOI] [PubMed] [Google Scholar]
- Kim D., Cragoe E. J., Jr, Smith T. W. Relations among sodium pump inhibition, Na-Ca and Na-H exchange activities, and Ca-H interaction in cultured chick heart cells. Circ Res. 1987 Feb;60(2):185–193. doi: 10.1161/01.res.60.2.185. [DOI] [PubMed] [Google Scholar]
- Kim D., Smith T. W. Cellular mechanisms underlying calcium-proton interactions in cultured chick ventricular cells. J Physiol. 1988 Apr;398:391–410. doi: 10.1113/jphysiol.1988.sp017049. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kleyman T. R., Cragoe E. J., Jr Amiloride and its analogs as tools in the study of ion transport. J Membr Biol. 1988 Oct;105(1):1–21. doi: 10.1007/BF01871102. [DOI] [PubMed] [Google Scholar]
- Lagadic-Gossmann D., Buckler K. J., Vaughan-Jones R. D. Role of bicarbonate in pH recovery from intracellular acidosis in the guinea-pig ventricular myocyte. J Physiol. 1992 Dec;458:361–384. doi: 10.1113/jphysiol.1992.sp019422. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lagadic-Gossmann D., Vaughan-Jones R. D., Buckler K. J. Adrenaline and extracellular ATP switch between two modes of acid extrusion in the guinea-pig ventricular myocyte. J Physiol. 1992 Dec;458:385–407. doi: 10.1113/jphysiol.1992.sp019423. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Liu S., Piwnica-Worms D., Lieberman M. Intracellular pH regulation in cultured embryonic chick heart cells. Na(+)-dependent Cl-/HCO3- exchange. J Gen Physiol. 1990 Dec;96(6):1247–1269. doi: 10.1085/jgp.96.6.1247. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MacLeod K. T., Harding S. E. Effects of phorbol ester on contraction, intracellular pH and intracellular Ca2+ in isolated mammalian ventricular myocytes. J Physiol. 1991 Dec;444:481–498. doi: 10.1113/jphysiol.1991.sp018889. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Morimoto A., Sakata Y., Watanabe T., Murakami N. Leucocytosis induced in rabbits by intravenous or central injection of granulocyte colony stimulating factor. J Physiol. 1990 Jul;426:117–126. doi: 10.1113/jphysiol.1990.sp018129. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Otani H., Otani H., Uriu T., Hara M., Inoue M., Omori K., Cragoe E. J., Jr, Inagaki C. Effects of inhibitors of protein kinase C and Na+/H+ exchange on alpha 1-adrenoceptor-mediated inotropic responses in the rat left ventricular papillary muscle. Br J Pharmacol. 1990 Jun;100(2):207–210. doi: 10.1111/j.1476-5381.1990.tb15783.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Powell T., Terrar D. A., Twist V. W. Electrical properties of individual cells isolated from adult rat ventricular myocardium. J Physiol. 1980 May;302:131–153. doi: 10.1113/jphysiol.1980.sp013234. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Roos A., Boron W. F. Intracellular pH. Physiol Rev. 1981 Apr;61(2):296–434. doi: 10.1152/physrev.1981.61.2.296. [DOI] [PubMed] [Google Scholar]
- Stimers J. R., Shigeto N., Lieberman M. Na/K pump current in aggregates of cultured chick cardiac myocytes. J Gen Physiol. 1990 Jan;95(1):61–76. doi: 10.1085/jgp.95.1.61. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Terzic A., Pucéat M., Clément O., Scamps F., Vassort G. Alpha 1-adrenergic effects on intracellular pH and calcium and on myofilaments in single rat cardiac cells. J Physiol. 1992 Feb;447:275–292. doi: 10.1113/jphysiol.1992.sp019002. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Thomas J. A., Buchsbaum R. N., Zimniak A., Racker E. Intracellular pH measurements in Ehrlich ascites tumor cells utilizing spectroscopic probes generated in situ. Biochemistry. 1979 May 29;18(11):2210–2218. doi: 10.1021/bi00578a012. [DOI] [PubMed] [Google Scholar]
- Vaughan-Jones R. D., Eisner D. A., Lederer W. J. Effects of changes of intracellular pH on contraction in sheep cardiac Purkinje fibers. J Gen Physiol. 1987 Jun;89(6):1015–1032. doi: 10.1085/jgp.89.6.1015. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vaughan-Jones R. D. Regulation of intracellular pH in cardiac muscle. Ciba Found Symp. 1988;139:23–46. doi: 10.1002/9780470513699.ch3. [DOI] [PubMed] [Google Scholar]
- Weissberg P. L., Little P. J., Cragoe E. J., Jr, Bobik A. The pH of spontaneously beating cultured rat heart cells is regulated by an ATP-calmodulin-dependent Na+/H+ antiport. Circ Res. 1989 Apr;64(4):676–685. doi: 10.1161/01.res.64.4.676. [DOI] [PubMed] [Google Scholar]
- Zheng J. S., Christie A., De Young M. B., Levy M. N., Scarpa A. Synergism between cAMP and ATP in signal transduction in cardiac myocytes. Am J Physiol. 1992 Jan;262(1 Pt 1):C128–C135. doi: 10.1152/ajpcell.1992.262.1.C128. [DOI] [PubMed] [Google Scholar]
- von Kügelgen I., Starke K. Noradrenaline-ATP co-transmission in the sympathetic nervous system. Trends Pharmacol Sci. 1991 Sep;12(9):319–324. doi: 10.1016/0165-6147(91)90587-i. [DOI] [PubMed] [Google Scholar]
