Cholinesterase activities in the autonomic nervous system of rabbits with experimental allergic neuritis: A biochemical study

Utilizing a colorimetric method with acetylthiocholine iodide (AThCh) as substrate and eserine and ethopropazine as inhibitors, the activities of AThCh-splitting enzymes, acetylcholinesterase (AChE) and non-specific esterase (ψChE) were determined in different structures of the autonomic nervous system (ANS) from the left and from the right sides of rabbits with experimental allergic neuritis (EAN) and controls. The total activity of AThCh-splitting enzymes showed a highly significant decrease in the ganglion nodosum and in the ganglia of the thoracal and abdominal paravertebral sympathetic chain in rabbits with clinical symptoms of ANS-involvement. Lesser but still significant changes were found in EAN-rabbits with motor symptoms but without ANS symptoms. No definite changes could be found in the superior cervical ganglia, the cervical sympathetic trunk or the interganglionic portions of the abdominal and thoracal paravertebral sympathetic chains. In samples with decreased total enzyme activities, both AChE and ψChE appeared to decrease to approximately the same extent. This study demonstrates that the activities of AThCh-splitting enzymes are decreased in EAN in parts of ANS innervating the heart, abdominal and pelvic organs, and suggests that enzyme activities not derived from the myelin sheath may be involved in the pathogenesis of this demyelinating disease.