The Effect of Testosterone Replacement on Intramedullary, Inguinal and Visceral Fat in Ovariectomized Rats

The present article aims to evaluate the impact of testosterone treatment on the expansion of visceral, subcutaneous and intramedullary adipose tissue of ovariectomized rats and the visceral and subcutaneous fat expression of peroxisome proliferator-activated receptors (PPARs) gamma. METHODS:  In total 48 female Wistar rats were castrated and randomly divided into 6 treatment groups: group E2 was submitted to estradiol 5 μg/day; group T, to testosterone 5 μg/day; group E2 + T, to estradiol 5 μg/day + testosterone 5 μg/day; group TT, to testosterone 30 μg/day; group E2 + TT, to estradiol 5 μg/day + testosterone 30 μg/day; and placebo was administered to group P. After 5 weeks, the rats were euthanized, the inguinal and visceral adipose tissues were harvested, weighted, and had their PPAR gamma expression evaluated by reverse transcription quantitative polymerase chain reaction (RT-qPCR). The right femurs were harvested and histologically prepared to perform the number count of the intramedullary adipocytes.

The expansion of visceral fat tissue was much higher in the TT group when compared with other treated groups (p < 0.001). The TT group also showed a higher expansion of inguinal fat (p < 0.01), and groups E2 + T and E2 + TT presented lower growth compared to the P group (p < 0.01). The number of femur intramedullary adipocytes only showed significant differences between groups TT and E2 + TT (p < 0.05). The expression of PPAR gamma showed no differences among the groups.

The use of testosterone in high doses leads to an important expansion in both visceral and inguinal adipose tissues. Association with estradiol exerts an expansion-repressive effect on the visceral and inguinal adipose tissues.