The effects of orchidectomy and supraphysiological testosterone administration on trabecular bone structure and gene expression in rats

Figures & data

Table 1. Genes of interest in the current study.

Gene	NCBI number	Name
Osteogenic
ALPL	NM_013059	Alkaline phosphatase
BGLAP	NM_013414	Osteocalcin or bone gamma-carboxyglutamate (gla) protein
COL1A1	NM_053304	Collagen, type I, alpha 1
Osteoclastic
ACP5	NM_019144	Acid phosphatase 5, tartrate resistant
CTSK	NM_031560	Cathepsin K
ITGB3	NM_153720	Integrin, beta 3
OPG & RANKL
OPG/TNFRSF11b	NM_012870	Osteoprotegerin/tumor necrosis factor receptor superfamily, member 11b
RANKL/TNFSF11	NM_057149	Receptor activator of nuclear factor kappa-b/tumor necrosis factor (ligand) superfamily, member 11

Figure 1. Serum testosterone level of the study groups. Orchidectomy was performed at week 0 and all rats were sacrificed at week 8. Testosterone enanthate at 7 mg/kg body weight was administered to the TE group for 8 weeks. Testosterone level decreased with orchidectomy and increased with testosterone enanthate treatment. #Indicates significant difference (p < 0.05) versus week 0 within the treatment group. *Indicates significant difference (p < 0.05) versus the SH group at week 8.

Figure 2. The trabecular structure at the proximal tibia of the rats in each study group. The image was obtained after 8 weeks of treatment and reconstructed using a μCT device. The trabecular structure of the ORX group was more porous compared to the SH and TE group.

Table 2. Trabecular structural indices of the study group.

	Bone volume (%)		Connectivity density		Structural model index		Trabecular number (mm^−1)		Trabecular thickness (mm)		Trabecular separation (mm)
	Mean	SEM	Mean	SEM	Mean	SEM	Mean	SEM	Mean	SEM	Mean	SEM
SH	16.500	1.827	91.905	10.769	2.018	0.149	3.208	0.270	0.068	0.001	0.308	0.024
ORX	9.810^a	1.099	35.341^a	2.711	2.219	0.100	1.805^a	0.094	0.070	0.003	0.567^a	0.036
TE	15.898^b	0.937	76.096^b	2.630	1.984	0.064	2.833^b	0.311	0.071	0.002	0.368^b	0.042

Letter “a” indicates p < 0.05 compared to SH group; “b” indicates p < 0.05 compared to ORX group.

Figure 3. The gene expression of the study groups. Gene expression was measured from sample extracted from the metaphysial region of distal tibia using multiplex quantigene technique. The mRNA expression of the target gene was normalized with the mRNA expression of beta-glucuronidase. Orchidectomy decreased the expression of osteogenic genes significantly (p < 0.05). Testosterone treatment significantly decreased the gene expressions of OPG and RANKL (p < 0.05). Letter ‘a’ indicates significant difference (p < 0.05) versus the SH group; ‘b’ indicates significant difference (p < 0.05) versus the ORX group.