EFFECTS OF ACRYLAMIDE ON SUBCELLULAR-DISTRIBUTION OF ELEMENTS IN RAT SCIATIC-NERVE MYELINATED AXONS AND SCHWANN-CELLS

Electron probe X-ray microanalysis was used to determine whether exper imental acrylamide (ACR) neuropathy involves deregulation of subcellul ar elements (Na, P, S, Cl, K, Ca and Mg) and water in Schwann cells an d small, medium and large diameter myelinated axons of rat sciatic ner ve. Results show that in proximal but not distal sciatic nerve, ACR tr eatment (2.8 mM in drinking water) was associated with an early (15 da ys of exposure), moderate increase in mean axoplasmic K concentrations (mmol/kg) of medium and small diameter fibers. However, all axons in proximal and distal nerve regions displayed small increases in dry and wet weight contents of axoplasmic Na and P. As ACR treatment progress ed (up to 60 days of exposure), Na and P changes persisted whereas pro ximal axonal K levels returned to control values or below. Alterations in mitochondrial elemental content paralleled those occurring in axop lasm. Schwann cells in distal sciatic nerve exhibited a progressive lo ss of K, Mg and P and an increase in Na, Cl and Ca. Proximal glia disp layed less extensive elemental modifications. Elemental changes observ ed in axons are not typical of those associated with cell injury and m ight reflect compensatory or secondary responses. In contrast, distal Schwann cell alterations are consistent with injury, but whether these changes represent primary or secondary mechanisms remains to be deter mined.