RAMAN MICROSPECTROSCOPY OF INTRACELLULAR CHOLESTEROL CRYSTALS IN CULTURED BOVINE CORONARY-ARTERY ENDOTHELIAL-CELLS

Raman microspectroscopy is presented as a promising technique for the in situ characterization of intracellular cholesterol crystals. Crysta l characterization is the first step in investigating the effects of v arious stimuli on their formation and in determining their role in the development of atherosclerosis. Treatment of cultured bovine coronary artery endothelial cells with 22-hydroxycholesterol (220HC) stimulate d the production of intracellular crystals, a phenomenon that did not occur in the absence of viable cells. These crystals were identified a s a combination of the 220HC starting material and cholesterol. The be st fit to the average Raman spectrum of the microscopic crystals was a chieved with a combination of 70% Raman contribution from 220HC and 30 % from cholesterol. GC/MS analysis of the crystals confirmed the prese nce of both compounds. These results demonstrate the potential of Rama n microspectroscopy as a powerful tool in lipid research, particularly for the in situ characterization of intracellular crystals.