84 PHYSIOLOGICAL TRIGGERS 



in an inactive state because of enzyme inhibition. The flash presumably occurs 

 when this inhibitory complex is split by pyrophosphate. It is possible that nerv- 

 ous stimulation to the cell could lead to the rapid liberation of inorganic pyro- 

 phosphate by means of the typical acetylcholine-coenzyme A-ATP cycle. It is 

 suggestive that the luminous organs contain a very high coenzyme A concentra- 

 tion. Unfortunately more direct evidence concerning this postulated mechanism 

 is not yet available. 



ADDENDUM 



Since this chapter was prepared there has ai)j)eared a paper by Hastings and Buck (Biol. 

 Bull. Ill: 101-113, 1956) on the eiTects of different oxygen tensions on the pseudotlash of fire- 

 fly photogenic tissue, which indirectly sup|)orts the theory here presented. 



REFERENCES 



1. Brown, D. E. S. and C. V. King. Physiol. Zool. 4: 2S7, 1931. 



2. Buck, J. Ann. New York Acad. Sci. 49: 297, 1948. 



3. Buck, John. In: The Luminescence of Biological Systems. Washington, D. C: .Xm. Assoc. 

 Advance. Sci., 1955, p. 323. 



4. Harvey, E. N. Bioluminescence. New York: Acad. Press, 1952. 



5. Hastings, J. W., \V. D. McElroy, and J. Coulombre. J . Cell & Com p. Physiol. 42: 137, 



1953- 



6. McElroy, VV. D. and J. \S . Hastings. In: The Luminescence of Biological Systems. Wash- 

 ington, D. C: .^m. Assoc. Advanc. Sci., 1955, p. 161. 



7. McElroy, W. D., J. W. Hastings, J. Coulombre and V. Sonnefeld. Arch. Biochem. 46: 

 399. 1953- 



