Abstract
The hypothesis was tested that wall tension can influence the membrane potential response to noradrenaline (NA) using isometric and isobaric vessel preparations of rat mesenteric small arteries. The resting membrane potential was significantly less negative in the isobaric (−49.7±0.5 mV, S.E.M., n=12 vessels) compared to the isometric preparation (−56.1±0.7 mV, n=10), although there was no difference in wall tension. The depolarization induced by 10−5 M NA was 2.6-fold smaller in the isobaric preparation, where wall tension decreased, compared to the isometric preparation, where wall tension increased. Since wall tension decreases under isobaric conditions, but increases under isometric conditions, the latter finding can be explained by assuming that part of the NA-induced membrane potential change is wall tension dependent.
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References
BUUS NH, VANBAVEL E, MULVANY MJ (1994) Differences in sensitivity of rat mesenteric small arteries to agonists when studied as ring preparations or as cannulated preparations.Br. J Pharmacol. 112: 579–587
DAVIS MJ, DONOVITZ JA, HOOD JD (1992) Stretch-activated single-channel and whole-cell currents in vascular smooth muscle cells.Am. J. Physiol. 262: C1083–C1088
DUNN WR, WELLMAN GC, BEVAN JA (1994) Enhanced resistance artery sensitivity to agonists under isobaric compared with isometric conditions.Am. J. Physiol. 266: H147–H155
HARDER DR (1984) Pressure-dependent membrane depolarization in cat middle cerebral artery.Circ. Res. 55: 197–202
HARDER DR, NARAYANAN J, GEBREMEDHIN D, ROMAN RJ (1995) Transduction of physical force by the vascular wall: Role of phospholipase C and cytochrome P450 metabolites of arachidonic acid.Trend. Cardiovasc. Med. 5: 7–14
LOMBARD JH, ESKINDER H, KAUSER K, OSBORN JL, HARDER DR (1990) Enhanced norepinephrine sensitivity in renal arteries at elevated transmural pressure.Am. J Physiol. 259: H29–H33
MULVANY MJ, NILSSON H, FLATMAN JA (1982) Role of membrane potential in the response of rat small mesenteric arteries to exogenous noradrenaline stimulation.J. Physiol. 332: 363–373
VANBAVEL E, MULVANY MJ (1994) Role of wall tension in the vasoconstrictor response of cannulated rat mesenteric small arteries.J. Physiol. 477: 103–115
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Schubert, R., Wesselman, J.P.M., Nilsson, H. et al. Noradrenaline-induced depolarization is smaller in isobaric compared to isometric preparations of rat mesenteric small arteries. Pflugers Arch. 431, 794–796 (1996). https://doi.org/10.1007/BF02253846
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DOI: https://doi.org/10.1007/BF02253846