QUANTITATIVE STUDIES ON LIPOLYTIC ENZYME ACTIVITY IN DEGENERATING AND REGENERATING NERVE

¹ Histochemistry Laboratory, Department of Physiological Chemistry, University of Minnesota

1. In the phenomenon of Wallerian degeneration in a cut peripheral nerve the process of myelin degradation in the distal stump is, by the ordinary staining methods of histology, unusually retarded in comparison with the same process in necrosis of nervous tissue, e.g. in infarcts.

2. The Glick acidimetric method for lipase and esterase in tissue sections was used to determine lipolytic esterase activity quantitatively in rabbit sciatic nerves above and below the line of experimental transection at varying intervals of time after operation.

3. The enzyme activity per milligram of tissue (dry weight) fell steadily in the peripheral stump to 40 per cent of the normal average value; while in the proximal stump in the region of the regenerating neurites it rose steadily to 300-400 per cent of normal. As reunion of the stumps occurred, the zone of highest esterase activity passed into the upper extremity of the now reunited distal portion.

4. Reasons are given for attributing the increased ali-esterase activity to the regenerating neurites themselves.