Statistical Analysis of Effects of Testosterone on Purine Metabolism in Rat Liver

Introduction

Previously, we have demonstrated that the liver is a target organ of testosterone, and that the gonads are not the only organ in which purine nucleotide metabolism is regulated by androgens [1]. Under normal conditions and after castration, testosterone presumably has several effects on the metabolism and functions of the liver; such effects must be studied in depth and still demand attention. For instance, liver of both sexes responds to sex steroid hormones, but the hepatic enzymes can be classified in different categories according to their response towards neonatal androgenic influence. After postpubertal castration, the enzyme activities can be differently restimulated by administration of testosterone propionate. No significant differences in physicochemical properties have been noted between hepatic steroid receptors and those from classical tissues, and after orchiectomy, any decrease in number of receptors per cell has been revealed [2] [3] [4] [5].

Due to the importance of these observations, we decided to check our results carefully. We carried out another set of experiments, which are in line with the precedent ones [1], analyzing the results with advanced statistical method SPSS [6], instead of the biomathematical model. We also extended the analysis of our results with the evaluation of the Adenine/Guanine (A/G) ratio in terms of specific activity and ¹⁴C-formate incorporation, in free adenine and guanine nucleotides, RNA-adenine, RNA-guanine, DNA-adenine, and DNA-guanine. The A/G ratio, a very important parameter, may represent impaired production of ATP [7] [8] [9].

The new procedures adopted have largely confirmed the results obtained by the biomathematical model. We have drawn many interesting conclusions from the statistical analysis, including that nucleotide metabolism is regulated by testosterone, not only in sex organs, but also in the liver. The interpretation of such behavior, before and after castration, is an open problem.

References

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