Journal of Andrology, Vol. 26, No. 6, November/December 2005
Copyright © American Society of Andrology
DOI: 10.2164/jandrol.05038
Trisialoganglioside GT1b Prevents Increase in Sperm Membrane Molecular Ordering Induced by In Vitro Lipid Peroxidation
MIRJANA GAVELLA*,
MARINA KVEDER
,
VASKRESENIJA LIPOVAC*,
ROMINA RAKOS* AND
GRETA PIFAT
From the * Vuk Vrhovac University Clinic for
Diabetes, Endocrinology and Metabolic Diseases, School of Medicine, University
of Zagreb, Zagreb, Croatia; and the
Ruder
Bo
kovi
Institute, Zagreb, Croatia.
|
Correspondence to: Dr Mirjana Gavella, Laboratory of Cell Biochemistry, Vuk
Vrhovac University Clinic for Diabetes, Endocrinology and Metabolic Diseases,
4a Dugi Dol, 10000 Zagreb, Croatia (e-mail:
mgavella{at}idb.hr). |
The effect of various types of gangliosides, the sialic acid-containing
glycosphingolipids, on human sperm membrane during lipid peroxidation induced
by Fe2+/ascorbate ions was investigated. The monosialoganglioside
(GM1), disialogangliosides (GD1a and GD1b), and trisialoganglioside (GT1b)
were examined at a concentration of 100 µM, which was above their
respective critical micellar concentrations. Lipid peroxidation was determined
by quantification of malondialdehyde (MDA) concentration. The molecular
orientational order in the membrane was assessed by fluorescence spectroscopy
and electron paramagnetic resonance spectroscopy. Both approaches revealed a
significant increase in membrane rigidity following oxidation, which
correlated with an increase in the MDA level. The preincubation of spermatozoa
with GM1 and GD1a did not have any effect on induced lipid peroxidation. In
the presence of GD1b and GT1b, a reduced formation of MDA and a decrease in
membrane rigidity was detected. The inhibitory effect of GT1b micelles toward
membrane oxidation damage was found to be greater than that of GD1b. In
conclusion, a direct relationship between the reduced content of the
accumulated MDA and the longer preservation of the native-like membrane
molecular ordering during sperm oxidation in the presence of GT1b suggests its
protective effect. This phenomenon could be due to the specific GT1b
conformation and its negative surface potential.
Key words: Membrane rigidity, gangliosides, spermatozoa
Copyright © 2005 by The American Society of Andrology.