1. K. Grette, Acta physiol. scand.56, suppl. 195 (1962).
2. W. W. Douglas, Br. J. Physiol.34, 451 (1968).
3. S. Ebashi, in Proc. of the 4th Int. Congress on Pharmacology (Ed.E. Eigenmann; Schwabe, Basel 1970), vol. 1, p. 32.
4. R. P. Rubin, Pharmac. Rev.22, 389 (1970).
5. G. V. R. Born andM. J. Cross, J. Physiol., Lond.168, 178 (1963).