“Lipid soluble antioxidants in the tissue of equine eyes

MARGARITA GUAJARDO; ANA TERRASA; GSTAVO ZAPATA; CARLOS ALBERTO MARRA

Buenos Aires

Congreso; VIII Jornadas Multidisciplinarias de la Sociedad Argentina de Biología.; 2006

Sociedad Argentina de Biología y UBA

LIPID SOLUBLE ANTIOXIDANTS IN THE TISSUES OF THE EQUINE EYES. Guajardo M., Terrasa A., Zapata G and Marra C.A. Cátedra de Bioquímica, INIBIOLP, Facultad de Ciencias Médicas de la UNLP. Cátedra de Patología Médica, Facultad de Ciencias Veterinarias. mguajardo@fcv.unlp.edu.ar The oxidative stress is a possible risk factor for eye diseases such as equine uveitis. The free radicals elicited during the inflammatory process often result in pathologic conditions. Polyunsaturated fatty acids (PUFAs) of membranes are the major targets for free radicals which produce lipid peroxidation. Because of the ability to scavenge free radicals of the lipid soluble antioxidants, the purpose of this study was: to quantify values of these kind of antioxidants in serum and different ocular tissues, and  to determine the fatty acid composition of ocular tissues with higher lipid content such as iris and retina. Equine serum and different tissues of health eyes were utilized. Lipid soluble antioxidants were quantified by HPLC and the fatty acids composition of lipids from retina and iris were analyzed by c-GLC. The level of lipid soluble antioxidants were expressed in nmol/mg lipids. Retina and iris show the higher concentrations of a-tocopherol (4.41 ± 0.83 and 5.80 ± 1.49, respectively). The retionoids were detected in appreciable concentration in the retina (0.37 ± 0.05) and the carotenoids content was similar in the retina and iris (0.64 ± 0.18 and 0.64 ± 0.13, respectively). The content of a-tocopherol and carotenoids were 135.86 ± 26.28 and 11.22 ± 2.50 in aqueous humour and 150.52 ± 8.62 and 32.43 ± 1.17 in serum. In the tissues poor in lipids (cornea and crystalline), minor levels of lipid soluble antioxidants were detected. The fatty acid compositions of retina and iris showed a high percentage of PUFAs mainly 22:6 n-3 and 20:4 n-6. The present experimental results show that equine eyes have an endogen pool of lipid soluble antioxidants, and their distribution in each tissue correlates with their susceptibility to oxidative damage.