The Choline-esterase Activity of the Blood Serum in Disease.

The investigations of Dale and his coworkers (1, 2) on the chemical transmission of parasympathetic nerve stimulation and of Walker (3, 4) on the use of physostigmine and prostigmin in myasthenia gravis have stimulated interest in the choline-esterase activity of serum. Lucas, Hall, and Ettinger (5) studied the serum esterase activity of 200 subjects and obtained results that were in essential agreement with the earlier findings of Stedman, Stedman, and Easson (6) and the more recent ones of McGeorge (7) on 132 patients. Although wide variations occurred among the subjects, the esterase activity was found to be constant over periods of many weeks, and no correlation with any type of clinical syndrome could be found. However, in myasthenia gravis conflicting findings have been reported. Thus, Hicks (8) found in one patient an abnormally high esterase activity which increased even further during exacerbations of the muscular symptoms. Stedman and Russell (9), on the other hand, observed serum esterase values in myasthenia gravis that were lower than in the other clinical conditions they studied, and believed that the distribution of the enzyme between the corpuscles and the serum was different from that in other conditions. In the present investigations the choline-esterase of the sera of 109 subjects was determined. The clinical syndromes studied included a wide variety of conditions. Some of the subjects were without organic disease; many were only moderately ill, and others were in the advanced or even final stages of disease. In many instances the serum esterase activity was studied at frequent intervals over periods of several months. The effect of many factors was investigated. These included the age, sex, body weight, and total muscular mass of the subjects, changes in the clinical status, convulsions, fasting, and changes in the concentration of the constituents of the blood such as the protein, hemoglobin, and red blood cells. Six of the patients had myasthenia gravis. Of these, three were in a special research ward for periods of several months where esterase determinatiorib were made practically every day, and often several times on the same day.