1. For autobiographical notes see Current Contents (1984), number 45, p. 23, and Schatzmann (1995).
2. Both mineralocorticoids and cardiotonic steroids contain a “cyclopentanoperhydrophenanthrene” nucleus, but they differ significantly in the folding of their rings.
3. Schatzmann (1953). Of the large family of cardiotonic steroids, two glycosides are important here: digoxin, which is widely used clinically, and ouabain, which is favored in laboratory studies because of its solubility in water (it can also be purified by recrystalization, an important advantage during this period). Ouabain minus its sugar, the aglycone, is strophanthidin; this highly lipid-soluble compound readily diffuses across cell membranes, unlike ouabain.
4. Ibid., p. 354.
5. Joyce and Weatherall (1954); Matchett and Johnson (1954); Koefoed-Johnsen (1957); Caldwell and Keynes (1959).