The effect of L-arginine on slow motility of mammalian outer hair cell.
The effect of L-arginine on the slow motility of mammalian cochlear outer hair cells was studied in this experiment. L-Arginine (3 mM) but not D-arginine (3 mM) or other amino acids (L-aspartate or L-glutamate) induced length increases of guinea pig outer hair cell. Similarly, the membrane-permeant cGMP analogues, 8-(4-chlorophenylthio)guanosine 3':5'-cyclic monophosphate (1 mM) or 8-bromo-guanosine 3':5'-cyclic monophosphate (1 mM) induced length increases of guinea pig outer hair cells. These length increases induced by L-arginine can be attenuated by a 30 min preincubation of the cells with the nitric oxide synthase inhibitors N(G)-nitro-L-arginine methyl ester hydrochloride (3 mM) or 7-nitroindazole (1 mM). Comparing the effects of L-arginine and ionomycin on cell length and intracellular calcium change in outer hair cells, both L-arginine and ionomycin were able to induce the elongation of outer hair cells but L-arginine did not change the fluorescence intensity of Fluo-3. Preincubation of the cells with EGTA (3 mM) for 40 min to reduce the extracellular calcium concentration did not influence the effect of L-arginine. This experiment demonstrated that nitric oxide/cGMP pathway involvement in regulating the slow motility of mammalian outer hair cells cannot be ruled out. The effect of L-arginine is independent of extracellular calcium concentration.
Lin
Min-Jon
MJ
Department of Life Sciences, Chung Shan Medical University, Taichung City, Taiwan. mjl@csmu.edu.tw
Su
Mao-Chang
MC
Tan
Ching-Ting
CT
Su
Ching-Chyuan
CC
Li
Shuan-Yow
SY
Lin
Ruey-Hseng
RH
Lin-Shiau
Shoei-Yn
SY
Hung
Chui-Chen
CC
Lee
Shiann-Yann
SY
D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002463:Cell Membrane Permeability; D002465:Cell Movement / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D004791:Enzyme Inhibitors / Q000494:pharmacology; D045604:Extracellular Fluid / Q000378:metabolism; D006168:Guinea Pigs; D018072:Hair Cells, Auditory, Outer / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D007191:Indazoles / Q000494:pharmacology; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009994:Osmolar Concentration
D004791:Enzyme Inhibitors; D007191:Indazoles; D001120:Arginine; D019001:Nitric Oxide Synthase; D006152:Cyclic GMP; D002118:Calcium; C080122:7-nitroindazole; D019331:NG-Nitroarginine Methyl Ester