To assess whether TNF-α causes inflammatory demyelination or axonal degeneration, we injected into rat sciatic nerve saline, 100 U and 1000 U of rhTNF-α and studied the electrophysiological and pathological effects. At day 1 electrophysiology showed a slight reduction of proximal compound muscle action potential amplitude and pathology showed edema, inflammatory infiltration of vessel walls and endoneurium only in nerves injected with 1000 U of rhTNF-α. At day 5, there was no demyelination and a percentage of degenerated fibers similar in the three groups. To study the blood-nerve barrier, fluorescein isothiocyanate-labelled albumin was given intravenously after intraneural injection. The nerves injected with 1000 U rhTNF-α showed a leakage of the tracer in the endoneurium. TNF-α does not appear, at the doses used, to have myelinotoxic or axonopathic properties. The electrophysiological effect at day 1 may be due to mechanical compression of nerve fibers as a result of the blood-nerve barrier damage with consequent endoneurial edema.
Uncini A., Di Muzio A., Di Guglielmo G., De Angelis M.V., De Luca G., Lugaresi A., et al. (1999). Effect of rhTNF-α injection into rat sciatic nerve. JOURNAL OF NEUROIMMUNOLOGY, 94(1-2), 88-94 [10.1016/S0165-5728(98)00229-X].
Effect of rhTNF-α injection into rat sciatic nerve
Lugaresi A.Penultimo
Conceptualization
;
1999
Abstract
To assess whether TNF-α causes inflammatory demyelination or axonal degeneration, we injected into rat sciatic nerve saline, 100 U and 1000 U of rhTNF-α and studied the electrophysiological and pathological effects. At day 1 electrophysiology showed a slight reduction of proximal compound muscle action potential amplitude and pathology showed edema, inflammatory infiltration of vessel walls and endoneurium only in nerves injected with 1000 U of rhTNF-α. At day 5, there was no demyelination and a percentage of degenerated fibers similar in the three groups. To study the blood-nerve barrier, fluorescein isothiocyanate-labelled albumin was given intravenously after intraneural injection. The nerves injected with 1000 U rhTNF-α showed a leakage of the tracer in the endoneurium. TNF-α does not appear, at the doses used, to have myelinotoxic or axonopathic properties. The electrophysiological effect at day 1 may be due to mechanical compression of nerve fibers as a result of the blood-nerve barrier damage with consequent endoneurial edema.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
