ELASTIN CONTENT OF THE AORTA AND THE PULMONARY ARTERY IN THE JAPANESE.

1. The authors made quantitative determinations of the elastin content of the aorta and the pulmonary artery in autopsy tissue specimens from Japanese varying in age from newborn infants to an 81-year old, in cases of accidental deaths (35 males and 22 females), using Scarselli's method. 2. Preliminary electron microscopic observations revealed that elastic fibers of rabbit aorta were fairly selectively diminished by the 4 per cent pancreatin solution, pH 9.5, which was used in Scarselli's method. 3. Elastin content of the aorta in each decade is as follows: 0 to 10 years, 32.9 per cent per nig of sample, dry weight; 11 to 20 years, 36.0 per cent; 21 to 30 years, 29.3 per cent; 31 to 40 years, 24.8 per cent; 41 to 50 years, 25,1 per cent; 51 to 60 years, 21.6 per cent; 61 to 70 years, 22.0 per cent; and 71 to 81 years, 21.1 per cent. 4. Elastin content of the pulmonary artery in each decade is as follows: 0 to 10 years, 27.7 per rent; 11 to 20 years, 31.2 per cent; 21 to 30 years, 26.8 per cent; 31 to 40 years, 27.4 per cent; 41 to 50 years, 27.6 per cent; 51 to 60 years, 25.4 per cent; 61 to 70 years, 23.6 per cent; and 71 to 80 years, 27.5 per cent. Elastin content of the pulmonary artery shows the maximal value in the 2nd decade, as does the aorta, but the decrease of the content is far less marked than that of the aorta. 5. The possible significance of these results was discussed. [ABSTRACT FROM AUTHOR]