Studies on Chemical Inhibition 

 of Regeneration in Hydra 



Robert E. Eakin 



Clayton Foundation Biochemical Institute and the Department of Chemistry, 

 The University of Texas, Austin, Texas. 



First, I would like to express my disappointment that Dr. Ham 

 and Dr. Spangenberg, former students of mine, were unable to get 

 to the meeting to present their own contributions. They were re- 

 sponsible for developing the research program I shall discuss. 



I would like to summarize the results of three phases of our 

 investigations: first, factors influencing the regenerative response of 

 hydra under normal conditions; second, the effects of chemical 

 agents upon regenerative processes; and third, some biochemical 

 observations on the effect of an agent which uniquely arrests regen- 

 eration — lipoic acid. (A fourth phase, histological studies on both 

 normal and treated organisms, is included on pp. 4L3-423 of this 

 volume. ) 



FACTORS INFLUENCING REGENERATION OF 

 UNTREATED HYDRA 



Seven years ago I would not have anticipated I would be at this 

 late date reporting on the control of factors influencing normal 

 regeneration. But we've had our troubles. 



When Dr. Ham originally initiated the use of hydra in our 

 laboratory, he did a thorough and comprehensive study on the 

 environmental factors which influence the regeneration rate of 

 H. littoralis (4). But over a period of several years' time, we en- 

 countered a considerable degree of inconsistency in the behavior of 



3.9.9 



