Levocarnitine acetyl prevents cell death following long-term section of the vagus nerve in rats

Levocarnitine acetyl has previously been found to significantly prevent axotomy-induced cell death in the spinal cord motor nucleus 9 and 12 months after section of the sciatic nerve in rats. In the present paper, the effects of levocarnitine acetyl on axotomy-induced cell death in the brain stem motor nuclei 90 days after section of the vagus nerve were studied. The right vagus nerve was cut at the neck. To prevent regeneration, a 5 mm-long segment of the vagus nerve was excised and the distal stump was displaced caudally. After surgery, a group of rats (n = 6) was treated with levocarnitine acetyl dissolved in the drinking water (75 mg/kg/day) (Group I). A second group of operated rats (n = 4) received drinking water alone. (Group II). Ninety days postoperatively, in the rats of both groups the proximal nerve stump of the vagus nerve was injected with horseradish peroxidase to label retrogradely the brain stem motoneurons of the dorsal motor vagal and the ambiguus nuclei. The brain stem nuclei were also labelled by horseradish peroxidase in three unoperated control rats (Group III). In the Group II rats, the number of horseradish peroxidase-labelled motoneurons of the dorsal motor vagal nucleus was found to be significantly smaller than in either the Group I (p < 0.01) or the Group III (p < 0.02) animals. In the Group I rats, the number of motoneurons of the dorsal motor vagal nucleus was not significantly smaller compared to the Group III rats.(ABSTRACT TRUNCATED AT 250 WORDS)