The effect of testosterone supplementation on capillar morphometry and vegf expression level of the heart in aged mice

Abstract

The aim of this study was to determine the effect of testosterone hormone supplementation on the capillary morphometry and VEGF expression level of the heart of old mice using histological and molecular techniques. A total of 30 old mice were enrolled in 3 groups: sham operation group (Control), gonadectomy group (G) and gonadectomy and testosterone supplementation group (GTS). The capillary number and the inner diameter of larger capillary vessels in the heart were measured by light microscope in terms of angiogenic processes. The levels of angiogenic factor, VEGF (vascular endothelial growth factor), mRNA in the heart tissue were determined by RT-PCR. The capillary densities decreased in female mice, in which G and GTS (P<0.05) groups compared to the control group, whereas there was no alteration in male mice. Gonadectomy led to a reduction in VEGF expression. Interestingly, testosterone replacement (in GTS group) caused even more reduction in VEGF expression in male and female (P<0.05) compared to the control group. The present results showed that there was a variation affected by gender in the regulation of angiogenesis by testosterone in the heart. However, testosterone replacement was not sufficient to restore the effects of gonadectomy on the heart in old mice.

Keywords

• angiogenesis
• testosterone
• aged mice
• heart