Role of unsaturated fatty acids in the enhancement of muscarinic current by hyposmotic membrane stretch in guinea pig smooth muscle cells
- Author:
- No author available
- Journal Title:
- ACTA PHYSIOLOGICA SINICA
- Issue:
- 1
- DOI:
- 10.3321/j.issn:0371-0874.2003.01.020
- Key Word:
- 不饱和脂肪;毒蕈碱电流;低渗牵张;幽门窦;豚鼠;unsaturated fatty acids;muscarinic current;hyposmotic stretch;gastric antral myocytes;guinea pig
Abstract： To investigate the function of exogenous unsaturated fatty acids in hyposmotic membrane stretch enhancement of muscarinic current (ICCh) in antral circular smooth muscle cells of guinea pig, we recorded the membrane current with the conventional whole cell patch-clamp technique. ICCh elicited by 50 μmol/L carbachol (CCh) at the holding potential of -20 mV under isosmotic condition was taken as control. Hyposmotic membrane stretch increased ICCh to 226.0±21.0%. When the cells were pretreated with 5 μmol/L arachidonic acid (AA), linoleic acid (LA) or oleic acid (OA), ICCh was inhibited to 3.8±0.6%, 35.2±0.8% and 66.6±0.6% respectively. Hyposmotic membrane stretch increased ICCh to 106.0±2.5%, 173.2±6.8% and 222.1±11.0% of the control respectively. Five μmol/L AA inhibited hyposmotic membrane stretch-enhanced ICCh by 51.2±3.8%, while the control ICCh under isosmotic condition was inhibited by 96.2±1.6%. The results suggest that unsaturated fatty acids inhibited ICCh and the inhibitory effect is more significant when the unsaturation degree is increased. However, the unsaturated fatty acids are not involved in the increase of ICCh induced by hyposmotic membrane stretch.
- [1]许文燮,李英,吴龙仁,等.不同牵张刺激对豚鼠胃窦环行肌细胞电压依赖性钙电流的影响[J].2000,(1).
- [2]Kim, Donghee,Pleumsamran, Apisate.Cytoplasmic Unsaturated Free Fatty Acids Inhibit ATP-dependent Gating of the G Protein-gated K... Channel.[J].2000,115(3).
- [3]H, Tinel,F, Wehner,R K, Kinne.Arachidonic acid as a second messenger for hypotonicity-induced calcium transients in rat IMCD cells.[J].1997,433(3).
- [4]Rhee JC,So I,Kim SJ,etc.Effect of stretch on calcium channel currents recorded from the antral circular myocytes of guinea-pig stomach.[J].1996,432(2).
- [5]R W, Ordway,J J, Singer,J V, Walsh.Direct regulation of ion channels by fatty acids.[J].1991,14(3).
- [6]X.B. Wang,T. Osugi,S. Uchida.Muscarinic Receptors Stimulate Ca2+ Influx via Phospholipase A2 Pathway in Ileal Smooth Muscles[J].1993,193(2).
- [7]禹永春,郭慧淑,朴琳,等.胞内钙参与低渗性膜牵张引起豚鼠胃窦环行肌细胞毒蕈碱受体门控电流增加的过程[J].2002,(11).
- [8]Thoroed SM.,Hansen HS.,Hoffmann EK.,etc.Cell Swelling Activates Phospholipase a(2) in Ehrlich Ascites Tumor Cells[J].1997,160(1).
- [9]R E, Tefft,A, Carruthers,D L, Melchior.Reconstituted human erythrocyte sugar transporter activity is determined by bilayer lipid head groups.[J].1986,25.
- [10]Naoki Matsuda,Nobuhisa Hagiwara,Morio Shoda,etc.Enhancement of the L-Type Ca2plus Current by Mechanical Stimulation in Single Rabbit Cardiac Myocytes[J].1996,78(4).
- [11]Reuss L.,Subramaniam M.,Torres R.,etc.Cell-volume changes and ion conductances in amphibian gallbladder epithelium [Review][J].2000,10(5).
- [12]M M, Souza,R T, Boyle.A moderate decrease in temperature inhibits the calcium signaling mechanism(s) of the regulatory volume decrease in chick embryo cardiomyocytes.[J].2001,34(1).
- [13]E K, Hoffmann,P B, Dunham.Membrane mechanisms and intracellular signalling in cell volume regulation.[J].1995,161.
- [14]N, Nagano,Y, Imaizumi,M, Watanabe.Modulation of calcium channel currents by arachidonic acid in single smooth muscle cells from vas deferens of the guinea-pig.[J].1995,116(2).
- [15]Strbak V.,Greer MA..Regulation of hormone secretion by acute cell volume changes: Ca2+-independent hormone secretion [Review][J].2000,10(5).
- [16]Basavappa S,Pedersen SF,Hoffmann EK,etc.Swelling-induced arachidonic acid release via the 85-kDa cPLA2 in human neuroblastoma cells.[J].1998,79(3).
- [17]Ordway R W,Petrou S,Kirber M T,etc.Stretch activation of a toad smooth muscle K+ channel may be mediated by fatty acids.[J].1995,484(2).
- [18]Fay FS,Tuft RA,Singer JJ,etc.Multiple pathways responsible for the stretch-induced increase in Ca2+ concentration in toad stomach smooth muscle cells.[J].2000,524(Pt.1).
- [19]Xu WX,So I,Rhee JC,etc.Volume-sensitive chloride current activated by hyposmotic swelling in antral gastric myocytes of the guinea-pig.[J].1997,435(1).
- [20]G Z, Xu,B, Shi,E J, McGroarty,etc.Channel-closing activity of porins from Escherichia coli in bilayer lipid membranes.[J].1986,862.
- [21]L, Liu,A R, Rittenhouse.Effects of arachidonic acid on unitary calcium currents in rat sympathetic neurons.[J].2000,525 Pt 2.