We have determined the endogenous phospholipids present in TM using triple quadrupole mass spectrometry in parent-ion and neutral loss scan modes with parameters that have been well established in the lipid field.
8 Such approaches recently have been made to characterize red blood cells from POAG patients,
29 and also for determining the composition of phospholipids of the optic nerve.
30,31 PC (22:6[4Z,7Z,10Z,13Z,16Z,19Z]/22:6[4Z,7Z,10Z,13Z,16Z,19Z]) was found uniquely in control TM tissues (
Table 3). The result is consistent with a previous study in which the level of PC (22:6[4Z,7Z,10Z,13Z,16Z,19Z]/22:6[4Z,7Z,10Z,13Z,16Z,19Z]) systemically decreases in the blood as the severity of glaucoma increases in POAG patients.
29,30 Phospholipid species PC (18:1[11Z]/22:6[4Z,7Z,10Z,13Z,16Z,19Z]) also have been identified uniquely (
Table 3) in control TM as well as red blood cells of control donors.
29,30 Taken together with recorded stiffness or rigidity of glaucomatous TM cells compared to controls,
32 a reduction of observed PCs in the glaucomatous TM cells is indicative of altered cell membrane fluidity in glaucoma.