Estrogens, Nucleic Acids, and Protein Synthesis in Uterine Metabolism

The tissues of the uterus, like most tissues, are composed chiefly of water; only one-fifth of the total weight is contributed by other substances. Proteins form the bulk of the solid material, constituting approximately 80% of the formed matter. The next most prominent uterine constituent by weight is deoxyribonucleic acid (DNA), which accounts for about 8% of the dry weight. DNA is followed in order by phospholipid, ribonucleic acid (RNA), and neutral fat. The remaining uterine components total approximately 5% of the dry weight and less than 1% of the total weight. A general outline of the chemical composition of the rat uterus is given in Table 1. It may be noted that many compounds, including intermediates of the glycolytic and citric acid cycles, some electrolytes, free amino acids, some mucopolysaccharides, and many other trace organic compounds have not been included in Table 1. A summary of the chemical composition of the uterus, based on several species in different stages of estrus and the menstrual cycle, has been compiled by Kosterlitz (1961).