The fluorescence anisotropy (r) of diphenylhexatriene (DPH) was measured in different preparations (bovine spinal cord phosphatidylserine liposomes, rat brain rnicrosomes, liposomes made with rat brain microsomal lipid having different phospholipid:cholesterol ratios) at temperatures ranging frorn lO· to 5SOC. Phosphatidylserine liposomes exhibited an exponential relationship of r versus temperature, whereas the relationship shown by microsomes and liposomes prepared with microsomal lipid extracts was a linear one. The removal of protein and high phospholipid:cholesterol ratios decreased the slope of the lines (f1uidity increased), although the intercept was unaffected. This means that differences were better appreciated at high temperatures and were well evident at 37·C. Acetyl-r.-camitine decreased r in rat brain microsomes and in liposomes made with microsomal lipids with different phospholipid:cholesterol ratios. The fluidifying effect of aceryl-r.-carnitine was mild but statistically significant and could explain, at least in part, the data reported in the literature of acetyl-L-camitine acting on some parameters affected by ageing. Besides, acetyl- L-camitine seemed to oppose the changes of viscosity due to lipid peroxidation, which has been reported to increase in ageing and dementia. L-camitine shares the properties of its acetyl ester, but only in part.
Acetyl-L-carnitine influences the fluidity of brain microsomes and of liposomes made of rat brain microsomal lipid extracts
CORAZZI, Lanfranco
1992
Abstract
The fluorescence anisotropy (r) of diphenylhexatriene (DPH) was measured in different preparations (bovine spinal cord phosphatidylserine liposomes, rat brain rnicrosomes, liposomes made with rat brain microsomal lipid having different phospholipid:cholesterol ratios) at temperatures ranging frorn lO· to 5SOC. Phosphatidylserine liposomes exhibited an exponential relationship of r versus temperature, whereas the relationship shown by microsomes and liposomes prepared with microsomal lipid extracts was a linear one. The removal of protein and high phospholipid:cholesterol ratios decreased the slope of the lines (f1uidity increased), although the intercept was unaffected. This means that differences were better appreciated at high temperatures and were well evident at 37·C. Acetyl-r.-camitine decreased r in rat brain microsomes and in liposomes made with microsomal lipids with different phospholipid:cholesterol ratios. The fluidifying effect of aceryl-r.-carnitine was mild but statistically significant and could explain, at least in part, the data reported in the literature of acetyl-L-camitine acting on some parameters affected by ageing. Besides, acetyl- L-camitine seemed to oppose the changes of viscosity due to lipid peroxidation, which has been reported to increase in ageing and dementia. L-camitine shares the properties of its acetyl ester, but only in part.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
