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DOI: 10.1055/s-2007-1010761
© Georg Thieme Verlag, Stuttgart · New York
Physiological Changes in Androgen Plasma Levels with Elapsing of Time from Castration in Adult Male Rats
Publication History
1986
1987
Publication Date:
14 March 2008 (online)
Summary
In the present study we investigated in adult male rats the effects of castration on Dehydroepiandrosterone (DHEA), Androstenedione (Δ4), Testosterone (T) and Dihydrotestosterone (DHT) plasma levels: five days (group II), seven weeks (group III) and eleven weeks (group IV) after orchiectomy.
The same hormone assays were performed in rats approximately 60 days of age which underwent a sham-operation for orchiectomy (group I).
Our data show that five days following orchiectomy (group II) Δ4, T and DHT were decreased with respect to sham-operated rats. (Group I: Δ4: 83.3±14.9 (SEM) ng/dl (n=12); T: 435.32±51.45 (n=12); DHT: 51.47±6.54 (n=12); Group II: Δ4: 44.81±6.09 (n=12) P = 0.05; T: 25.54±2.88 (n=12) P < 0.01; DHT: 12.9±2.51 (n=12) P < 0.01). Seven weeks afterwards T and DHT remained significantly lower (group III: T: 54.37±12.21, n=16) (P < 0.01; DHT: 33.22±4.49 (n=16) P < 0.01) while eleven weeks after all steroids were significantly decreased with respect to the values observed in sham-operated rats. (Group IV) Δ4: 32.01±5.7 (n=10) P < 0.01; T: 27.29±7.05 (n=10) P < 0.01; DHT: 29.03±5.34 (n=10) P < 0.01).
In all three groups of castrated animals the Δ4/T ratio appeared significantly augmented (group I: 0.24±0.007 (n=12); group II: 2.27±1.7 (n=12) P < 0.01; group III: 2.07±0.7 (n=11) P < 0.001; group IV: 1.47±0.85 (n=10) P < 0.01) while the T/DHT ratio was significantly lower with respect to the sham-operated rats (group I: 9.36±0.93 (n=12); group II: 2.57±0.32 (n=12) P < 0.01; group III: 2.12±0.48 (n=16) P < 0.01; group IV: 1.02±0.15 (n=10). This suggests that DHT in orchiectomized rats could be derived from other precursors than T.
Five days after castration (group II) DHEA was positively related to Δ4 (r=0.74 (n=12) 0.02 > P > 0.01) and both steroids were negatively related to T (DHEA: r=-0.79 (n=12) P<0.01; Δ4: r=-0.80 (n=12) P < 0.01) while in group IV an inverse correlation appeared between the DHEA/Δ4 ratio and T circulating levels (r=-0.648 (n=10) P=0.05).
This emphasizes the role of DHEA and Δ4 in maintaining testosterone circulating levels. Finally in the same two groups the negative correlation observed between the Δ4/T and T/DHT ratios (group III: r=-0.68 (n=11) P < 0.05; group IV: r=-0.63 (n=10) P = 0.05) indicates an important contributory role of Δ4 in affecting circulating levels of DHT in adult orchiectomized rats with the elapsing of time after castration.
Key-Words
Androgen - Orchiectomy