Letter to the Editor

LETTER TO THE EDITOR Dear Sir: Raacke [1] is incorrect in thinking that "no serious attempts to produce a unified theory of hormone action have been made in recent times," since Sir Julian Huxley tried it back in 1935 [2], which is relatively recent as studies of hormone action go. Huxley suggested that hormones should be regarded as information-transferring molecules, regardless of how they were transported, and I believe this is stiU more useful than either Starling's original definition or the modified version proposed by Raacke. We discussed this general problem, albeit in a pretty unsophisticated manner, in our 1971 monograph on cyclic AMP [3]. We concluded then that there were at least two different types of hormones, which could be thought ofin the present context as those that act the way Raacke thinks all hormones act, on the one hand, and diose that don't, on the other. We suggested that it might be helpful to retain the word "hormone" for one type and think ofa different word for the other, but eventually concluded that it would be best to simply remember that there are two different types of hormones. I think this is still the most reasonable attitude to take toward the problem. As for Raacke's suggestion that cyclic AMP may at times interact with nuclear proteins to affect the genome, the evidence for this was reviewed recently in considerable detail byJohnson [4], and readers interested in bringing themselves up to date in this area are advised to consult this article. An important point to keep in mind is that many ofthe physiologically important effects ofcyclic AMP have nothing to do with the genome, as discussed, for example, by Nimmo and Cohen [5]. REFERENCES 1.I. D. Raacke. Perspect. Biol. Med., 21:139, 1977. 2.J. S. Huxley. Biol. Rev., 10:427, 1935. 3.G. A. Robinson, R. W. Butcher, and E. W. Sutherland. Cyclic AMP. New York: Academic Press, 1971. 4.E. M.Johnson. Adv. Cyclic Nucleotide Res., 8:267, 1977. 5.H. G. Nimmo and P. Cohen. Adv. Cyclic Nucleotide Res., 8:144. 1977. G. Alan Robison Department ofPharmacology University of Texas Houston, Texas 77025 Permission to reprint this letter may be obtained only from the author. 638 I Letter to the Editor ...