Mitosis of Heart Muscle Cells in Normal Rats

Abstract

In order to demonstrate mitotic figures of the heart muscle cells and the interstitial cells during normal growth, colchicine was given to a total of 20 rats of various ages and mitosis in the myocardial cells was evaluated. The mitotic rate of heart muscle cells in 4 hours was 1.9-2.1% on the first day of life and it gradually decreased to 0.1% in 4 weeks and zero thereafter. The mitotic rate of interstitial cells was 2.0-2.2% on the first day of life and it similarly decreased to 0.1% in 6 months. These results seem to support our view that heart muscle cells and interstitial cells divide and increase in number with postnatal growth of the heart.