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  • Author or Editor: Richard L. Engen x
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SUMMARY

High-performance liquid chromatography (hplc) was used to determine the phospholipid (pl) composition of ovine, equine, bovine, porcine, and canine RBC membranes. Procedural modifications of established techniques provided for separation of 7 pl within a 15- to 20-minute sample run. Significant (P < 0.05) differences were detected in rbc membrane pl composition among the various species. The concern for physiologic properties associated with hemolysis and/or sedimentation rate must include evaluation of differences in the pl bilayer structure.

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in American Journal of Veterinary Research

Summary

Corynebacterium pseudotuberculosis produces a sphingomyelin-specific phospholipase D exotoxin that is a major determinant in the pathogenesis of caseous lymphadenitis. The effect of this exotoxin on erythrocytes was assessed during experimentally induced infection of sheep. Blood was drawn at timed intervals, and the phospholipid composition of erythrocytes was determined by use of high-performance liquid chromatographic analysis of membrane extracts. Erythrocyte morphology was determined by use of transmission electron microscopy. Significant (P ≤ 0.05) decreases in erythrocyte membrane sphingomyelin content and significant (P ≤ 0.05) increases in phosphatidylglycerol content were observed 30 minutes after iv inoculation of C pseudotuberculosis. The concentration of other phospholipids remained unchanged. Initially, spherostomatocytes were formed that later became pitted at the cell surface. These pits or invaginations appeared as numerous vacuoles at the periphery of thin-sectioned cells. Pitting became progressively worse, leading to an extensive scalloped cell surface. Alterations in the phospholipid composition and morphology of ovine erythrocytes may contribute to pathophysiologic findings in sheep with acute infection induced by C pseudotuberculosis.

Free access
in American Journal of Veterinary Research