Abstract
As a preliminary to a study of the effect of digitalization on the progress of experimental cardiac hypertrophy, we administered digalen and digifoline subcutaneously 0.1 C.U. semi-weekly to one series of 10 rabbits for 4 weeks and to 6 other rabbits for 14 to 18 weeks. These animals were then sacrificed and the hearts divided. Muscle from each ventricle was analyzed for creatine by Myer's modification 1 of the method of Rose, Helmar and Chanutin. These values were reduced to terms of dried weight by drying one sample at 105°C. to constant weight, then determining the percentage of solids.
Large rabbits such as were used in these and subsequent studies on hypertrophy, weighed 2200 to 3200 gm. and showed normal creatine values averaging 180 mg. % with solids averaging 22.3%.
Of the 10 rabbits digitalized for 4 weeks, 3 showed essentially normal creatine and total solids content, while the other 7 showed increased levels, as indicated in Table I. In the series in which digitalis injections were continued for 14 to 18 weeks the creatine percentages were slightly higher while the solids had dropped slightly. Simultaneous studies of the vastus lateralis in all of these rabbits revealed values normal for this muscle creatine (400 mg. %) and solids (24%). Thus the digitalis effect in so far as evidenced by the creatine changes is specific for heart muscle. The digitalization evidently produced no change in the heart weight-body weight or left to right ventricular ratios. The normal ratios are recorded in a preceding report. 2
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