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The Parallel Accumulation and Distribution of Two Purine-Oxidizing Enzymes During Frog Development


Barrett, Dennis (1963) The Parallel Accumulation and Distribution of Two Purine-Oxidizing Enzymes During Frog Development. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/0TRM-B219.


The patterns of two specialized and functionally related enzymes were investigated in the developing frog (Rana temporaria and Rana catesbeiana). Xanthine dehydrogenase (E.C. 1.2.1.) and uricase (E. C. 1. 7 . 3 . 2.) were found to remain apparently constant during the first ten days of normal development, both rising rapidly thereafter, beginning at the same larval stage. Comparison with enzymes of similar developmental pattern suggests this phase-specific increase is in preparation for the onset of digestive activity.

The same parallelism between uricase and xanthine dehydrogenase was observed when determinations were extended to the organ level. Each enzyme was found in quantity in liver and kidney, and in trace amounts, all of about the same magnitude, in several other organs tested.

By detecting radioactive tracer amounts of product, very low levels of xanthine dehydrogenase were measured in embryonic stages, probably corresponding to the order of small numbers of molecules per cell.

Evidence was gathered to suggest that embryonic uricase accumulation is neither induced by its substrate nor involved with the subcellular particles in which the enzyme is found.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Biochemistry)
Degree Grantor:California Institute of Technology
Major Option:Biochemistry
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Mitchell, Herschel K.
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1963
Record Number:CaltechTHESIS:02272012-160448464
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:6836
Deposited On:28 Feb 2012 17:52
Last Modified:05 Jan 2024 00:37

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