Changes in the nucleic acids metabolism in uromastyx microlepis during the entry, deep and arousal phases of hibernation

الملخص EN

Studies were carried out to explore the nucleic acid profile in different tissues of the hibernating reptile spinytailed lizard, Uromastyx microlepis.

Also, the changes in alkaline phosphatase and 5’- nucleotidase enzymes activity in serum and different tissues during the different phases of the hibernating cycle in the Uromostyx were studied.

The data obtained are as follow :- the present results revealed the occurrence of initial elevations in DNA content of different tissues of animal in preparation for hibernation followed by a continuous decline during hibernation.

The decline recorded in the DNA content reflect the occurrence of decreased rate of biosynthesis of DNA of different tissues in Uromostyx during the hibernating season.

The analysis of RNA revealed that hibernation caused a significant decline in its content in liver and kidney of animal.

Conversely, brains did not follow that profile, whereas in hibernating U.

microlepis, brain RNA increased and was maintained at high level till arousal.

The alkaline phosphatase activity declined in hibernation in serum and different tissues of Uromastyx and restored its activity on arousal.

The data indicate a close correlation between the DNA profile and the changes recorded for alkaline phosphatase, which plays the important role of furnishing the required mononucleotide, in preparation for hibernation followed by a declining activity during deep hibernation. The 5´-nucleotidase activity of liver and kidney showed an initial decline in preparation for hibernation followed by an increase on hibernation and declined on arousal to the active level especially in liver.

In serum and brain, 5´-nucleotidase exhibited a continuous decline during the hibernating cycle, which restored its activity on arousal to reach the active level.

The data indicate that nucleic acids assume optimum concentrations allowing the animal to maintain a minimal control over protein metabolism.