Human sciatic nerve phospholipids obtained from non-diabetes mellitus (NDM), non-insulin-dependent diabetes mellitus (NIDDM), and insulin-dependent diabetes mellitus (IDDM) patients, after lower extremity amputation, were studied by 31P NMR spectrometry. 2. Nine phospholipids resonances in NDM and NIDDM groups were identified as followed: Ethanolamine plasmalogen (Eplas, Chemical shift = 0.07 delta); phosphatidylethanolamine (PE, 0.03 delta); phosphatidylserine (PS, -0.05 delta); sphingomyelin (SM, -0.09 delta); lysophosphatidylcholine (LPC, -0.28 delta); phosphatidylinositol (PI, -0.30 delta); alkylacylphosphorylcholine (A1.PC, -0.78 delta); phosphatidylcholine (PC -0.84 delta), and an unknown resonance (U, 0.13 delta). 3. In the IDDM group a resonance of lysophosphatidylinositol (LPI, 0.01 delta) was detected in addition to the nine phospholipids listed above. 4. IDDM showed that PI and A1.PC were elevated and U was lower when compared with NDM; also, Eplas was lower when compared with NIDDM. PC was elevated and PS was lower when compared with both NDM and NIDDM. 5. Indices calculated from this data, showed that the choline ratio and choline/ethanolamine ratio were elevated; while ethanolamine ratio, and myelin ratio were lower in IDDM group, when compared with both NDM and NIDDM groups. 6. Inactivation of the cholineacethyltransferase enzyme (ChAT) and enhancement of the phospholipidmethyltransferase enzyme (PLMT), secondary to an insulin deficiency, are proposed as an interpretation of these findings.
