Abstract
Here we describe a pressure-clamp method for applying suction or pressure steps to membrane patches in order to study the activation, adaptation and relaxation characteristics of mechanosensitive (MS) channels. A description is given of the mechanical arrangement of the pressure clamp which involves a balance between negative (suction) and positive pressures. The electronic circuitry of the feedback control is described. We also describe the optimal time response (≈ 10 ms) of the pressure-clamp, the amplitude of pressure resolution (0.2–0.5 mmHg; 27–67 Pa) and the factors influencing these parameters. We illustrate the applications of the clamp on the Xenopus oocyte and cultured skeletal myotubes from dystrophic mouse (mdx) muscle, both of which express MS channels. Studies with pressure/suction pulses indicate that in both muscle and oocytes MS channel activity displays adaptation. The ability to study current relaxations following step changes in pressure/suction using the pressure-clamp in combination with patch-clamp techniques provides the opportunity for analysis of the time, voltage and pressure dependence of the opening and closing of MS channels.
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References
Christensen O (1987) Mediation of cell volume regulation by Ca2+ influx through stretch-activated channels. Nature 330:66–68
Corey DP, Hudspeth AJ (1980) Mechanical stimulation and micromanipulation with piezoelectric bimorph elements. J Neurosci Methods 3:183–202
Crawford AC, Evans MG, Fettiplace R (1991) The actions of calcium on the mechano-electrical transducer current of turtle hair cells. J Physiol (Lond) 434:369–398
Erxleben C (1989) Stretch-activated current through single ion channels in the abdominal stretch receptor organ of the crayfish. J Gen Physiol 94:1071–1083
Franco Jr A, Lansman JB (1990) Calcium entry through stretch inactivated ion channels in mdx mouse. Nature 344:670–673
French AS (1992) Mechanotransduction. Annu Rev Physiol 54:135–152
Gray JAB, Malcolm JL (1950) The initiation of nerve impulses by mesenteric Pacinian corpuscles. Proc R Soc Lond [B] 137:96–140
Guharay F, Sachs F (1984) Stretch-activated single ion channel currents in tissue cultured chick skeletal muscle. J Physiol (Lond) 352:685–701
Gustin MC, Zhou X-L, Martinac B, Kung C (1988) A mechanosensitive ion channel in the yeast plasma membrane. Science 242:762–765
Hamill OP (1983) Potassium and chloride channels in red blood cells. In: Sakmann B, Neher E (eds) Single channel recording. Plenum, New York, pp 451–471
Hamill OP, Marty A, Neher E, Sakmann B, Sigworth FJ (1981) Improved patch clamp techniques for recording from cells and cellfree membrane patches. Pflügers Arch 391:85–100
Hamill OP, McBride DW Jr (1992) Rapid adaptation of single mechanosensitive channels in Xenopus oocytes. Proc Natl Acad Sci USA 89(16):7462–7466
Hudspeth AJ (1989) How the ear's works work. Nature 341: 397–404
Lane JW, McBride DW Jr, Hamill OP (1991) Amiloride block of the mechanosensitive cation channel in Xenopus oocytes. J Physiol (Lond) 441:347–366
Loewenstein WR, Mendelson M (1965) Components of receptor adaptation in a pacinian corpuscle. J Physiol (Lond) 177:377–397
Martinac B (1992) Mechanosensitive ion channels: biophysics and physiology. In: Jackson MB (ed) Thermodynamics of cell surface receptors. CRC, Boca Raton (in press)
Martinac B, Buechner M, Delcour AH, Adler J, Kung C (1987) Pressure-sensitive ion channels in Escherichia coli. Proc Natl Acad Sci USA 84:2297–2301
Methfessel C, Witzemann V, Takahashi T, Mishina M, Numa S, Sakmann B (1986) Patch clamp measurements on Xenopus laevis oocytes: currents through endogenous channels and implanted acetylcholine receptor and sodium channels. Pflügers Arch 407:577–588
Moody WJ, Bosma MM (1989) A nonselective cation channel activated by membrane deformation in oocytes of the ascidian Boltenia villosa. J Membr Biol 107:179–188
Morris CE (1990) Mechanosensitive ion channels. J Membr Biol 113:93–107
Morris CE, Horn R (1991) Failure to elicit neuronal macroscopic mechanosensitive currents anticipated by single channel studies. Science 251:1246–1249
Ohmori H (1985) Mechano-electrical transduction currents in isolated vestibular hair cells of the chick. J Physiol (Lond) 359:189–217
Sachs F (1988) Mechanical transduction in biological systems. CRC Crit Rev Biomed Eng 16:141–169
Sackin H (1989) A stretch-activated K+ channel sensitive to cell volume. Proc Natl Acad Sci USA 86:1731–1735
Sokabe M, Sachs F (1990) The structure and dynamics of patch-clamped membranes: a study using differential interference contrast light microscopy. J Cell Biol 111:599–606
Taglietti V, Toselli M (1988) A study of stretch-activated channels in the membrane of frog oocytes: interactions with Ca++ ions. J Physiol (Lond) 407:311–328
Ubl J, Murer H, Kolb H-A (1988) Ion channels activated by osmotic and mechanical stress in membranes of opossum kidney cells. J Membr Biol 104:223–232
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McBride, D.W., Hamill, O.P. Pressure-clamp: a method for rapid step perturbation of mechanosensitive channels. Pflügers Arch. 421, 606–612 (1992). https://doi.org/10.1007/BF00375058
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DOI: https://doi.org/10.1007/BF00375058