Lipid alterations correlate with tissue magnesium decrease following impact trauma in rabbit spinal cord

Abstract

Secondary neurochemical events contribute to progressive tissue damage and subsequent neurological deficit after traumatic spinal-cord injury (SCI). Among proposed injury factors are alterations of phospholipids and certain cations. To clarify the relationship of membrane lipid changes (phospholipids, cholesterol, and arachidonic acid) to changes in tissue content of water and selected ions (sodium, potassium, and magnesium) after SCI, these variables were examined in spinal-cord segments from anesthetized ventilated rabbits subjected to laminectomy or to moderate (40 g-cm) or severe (150 g-cm) impact trauma at the lumbar (L2) segment. Trauma caused significant increases in tissue sodium, water, and arachidonic acid content, and significant decreases in phospholipids, cholesterol, potassium, and magnesium content. Alterations in magnesium were significantly related to injury severity. In contrast, changes in spinal-cord water content occurred to a similar degree in the two injury groups, as did tissue sodium and potassium content. Decreases in phospholipids were strongly correlated with decreases in tissue magnesium content, whereas changes in sodium and potassium were less well-correlated. Because magnesium ions play a critical role with regard to cellular bioenergetic state, calcium flux, amino acid receptor function, and eicosanoid production, reductions in tissue magnesium after injury may be important in the progression of secondary tissue damage.

A nutrient combination designed to enhance synapse formation and function improves outcome in experimental spinal cord injury

“…Phospholipid levels are significantly decreased after SCI (Lemke et al, 1990). Deficiency in vitamin C (Katoh et al, 1996), or vitamin E (Taoka et al, 1990), negatively impacts the outcome of SCI.…”

Dynorphin A-(1-17) induces alterations in free fatty acids, excitatory amino acids, and motor function through an opiate-receptor-mediated mechanism

“…Free fatty acids (FFAs). Changes in FFAs were measured, as previously described (Lemke et al, 1990). In brief, total lipids were extracted from brain tissues by homogenizing samples in 2 ml hexane:2-propanol (3:2, vol/vol; Hara and Radin, 1978;Saunders and Horrocks, 1984).…”

Does loss of gray- and white-matter contrast in injured spinal cord signify secondary injury? In vivo longitudinal MRI studies

“…A number of studies have also demonstrated a transient loss of cholesterol in injured spinal cord tissue (10)(11)(12)(13). Based on these two observations, we hypothesized that the observed transient loss in GM-WM contrast in injured cord may be due to the loss of myelin-bound cholesterol.…”