5-methoxytryptophol preserves hepatic microsomal membrane fluidity during oxidative stress
✍ Scribed by J.J. García; R.J. Reiter; J.J. Cabrera; J. Pié; J.C. Mayo; R.M. Sáinz; D.-X. Tan; W. Qi; D. Acuña-Castroviejo
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 121 KB
- Volume
- 76
- Category
- Article
- ISSN
- 0730-2312
No coin nor oath required. For personal study only.
✦ Synopsis
Lipid peroxidation is a degenerative chain reaction in biological membranes that may be initiated by exposure to free radicals. This process is associated with changes in the membrane fluidity and loss of several cell membrane-dependent functions. 5-methoxytryptophol (ML) is an indole isolated from the mammalian pineal gland. The purpose of this study was to investigate the effects of ML (0.01mM-10mM) on membrane fluidity modulated by lipid peroxidation. Hepatic microsomes obtained from rats were incubated with or without ML (0.01-10 mM). Then lipid peroxidation was induced by FeCl 3 , ADP, and NADPH. Membrane fluidity was determined using fluorescence spectroscopy. Malonaldehyde (MDA) ϩ4-hydroxyalkenals (4-HDA) concentrations were estimated as an indicator of the degree of lipid peroxidation. With oxidative stress, membrane fluidity decreased and MDAϩ4-HDA levels increased. ML (0.01-3 mM) reduced membrane rigidity and the rise in MDAϩ4-HDA formation in a concentrationdependent manner. 10 mM ML protected against lipid peroxidation but failed to prevent the membrane rigidity. In the absence of oxidative reagents, ML (0.3-10 mM) decreased membrane fluidity whereas MDAϩ4-HDA levels remained unchanged. This indicates that ML may interact with membrane lipids. The results presented here suggest that ML may be another pineal indoleamine (in addition to melatonin) that resists membrane rigidity due to lipid peroxidation.