Bone Mineral Density Changes after Orchiectomy using a Scrotal Approach in Rats

Effects on Bone and Muscle upon Treadmill Interval Training in Hypogonadal Male Rats

Testosterone deficiency in males is linked to various pathological conditions, including muscle and bone loss. This study evaluated the potential of different training modalities to counteract these losses in hypogonadal male rats. A total of 54 male Wistar rats underwent either castration (ORX, n = 18) or sham castration (n = 18), with 18 castrated rats engaging in uphill, level, or downhill interval treadmill training. Analyses were conducted at 4, 8, and 12 weeks postsurgery. Muscle force of the soleus muscle, muscle tissue samples, and bone characteristics were analyzed. No significant differences were observed in cortical bone characteristics. Castrated rats experienced decreased trabecular bone mineral density compared to sham-operated rats. However, 12 weeks of training increased trabecular bone mineral density, with no significant differences among groups. Muscle force measurements revealed decreased tetanic force in castrated rats at week 12, while uphill and downhill interval training restored force to sham group levels and led to muscle hypertrophy compared to ORX animals. Linear regression analyses showed a positive correlation between bone biomechanical characteristics and muscle force. The findings suggest that running exercise can prevent bone loss in osteoporosis, with similar bone restoration effects observed across different training modalities.

Korean Medicine Treatment for Managing Complex Regional Pain Syndrome: Case Report

A 53-year-old male who had received surgery on his right ankle joint 10 years previously was diagnosed with Complex Regional Pain Syndrome the following year. Despite various treatments (sympathetic nerve-block medication, pain relievers, corticosteroids, nerve blocks, and transcutaneous electrical nerve stimulation) over the years there was no improvement in his symptoms. Recently the patient was admitted to a Korean medicine hospital where he received treatment (acupuncture, pharmacopuncture, and herbal treatment) and his symptoms gradually showed improvement. The patient was concurrently on psychiatric medicine, antihistamine medication, and opioids for pain (when necessary). A decrease in numeric rating scale, Oswestry disability index scores, and an increase in the Korean version of the 5-level EuroQol-5 dimension score showed symptom improvement within 36 days. This study suggests complex Korean medicine treatment for Complex Regional Pain Syndrome may result in a reduction in pain and improved quality of life.

Sex Hormone Suppression and Physical Activity: Possible Implications for Transgender Individuals

Purpose

Transgender individuals tend to be less physically active than cisgender individuals, and the primary focus of these physical activity barriers have been psychosocial in nature. Very little attention has been given to the role that changes in the sex hormone milieu (such as that occurring during gender-affirming hormone therapy) play on physical activity. The purpose of this study was to explore the effects of sex hormone suppression using a gonadotropin-releasing hormone agonist (GnRHa) on physical activity levels and patterns.

Methods

Female and male rats received 4 weeks of sex hormone suppression using the GnRHa goserelin acetate (GA) or received a placebo as a control (CON). Animals were then allowed free access to voluntary running wheels, and activity was recorded throughout the treatment period.

Results

Female rats receiving GA (F GA) had a significantly lower total wheel running distance than female CON (F CON, 53±11 km vs. 113±28 km, respectively, p=0.042), and male rats receiving GA (M GA) had a significantly lower total wheel running distance when compared with male CON (M CON, 31±7 km vs. 69±18 km, respectively, p=0.037). Differences in daily wheel running distances were first observed at day 18 between F GA and F CON (p=0.037) and at day 2 between M GA and M CON (p=0.021).

Conclusion

Reduced sex hormone availability reduced wheel running activity in female and male rats. Understanding the role that sex hormone manipulation has on physical activity may be an important consideration in promoting physical activity in transgender individuals receiving treatments that reduce sex hormone availability.

Physiological testosterone replacement effects on male aged rats with orchiectomy-induced osteoporosis in advanced stage: a tomographic and biomechanical pilot study

Aim: This study aimed to evaluate the effect of physiological testosterone replacement on male aged rats with orchiectomy-induced osteoporosis in advanced stage.Methods: Thirty male rats (Rattus norvegicus albinus, Holtzman lineage) were randomly distributed into 3 groups (n = 10): 1-sham, 2-orchiectomy (OCX), 3-OCX + testosterone replacement (OCX + T). On day 0, a sham or orchiectomy surgery was performed according to the groups. Thirty and sixty days after surgeries, the animals from OCX + T group received testosterone intramuscularly, and the rats in all groups were euthanized on day 77. The femurs were removed for micro-CT scanning and biomechanical test.Results: Orchiectomy resulted in a marked trabecular bone damage (p < 0.05), which was not reversed with testosterone treatment (OCX + T group). The femoral strength was lower in orchiectomized animals (p < 0.05), while the bone strength in OCX + T group was similar to that observed in the sham animals (p > 0.05) and correlated to this parameter the deformation of rupture was smaller in OCX + T group.Conclusion: In conclusion, testosterone depletion induced by orchiectomy established an osteoporotic environment, mainly affecting the trabecular bone. Moreover, even though testosterone treatment did not enhance these variables, the hormonal replacement improved the femoral fracture strength and promoted beneficial effects on the biomechanical parameters compromised by castration in femoral bone.

Effect of Selective Androgen Receptor Modulator Enobosarm on Bone Healing in a Rat Model for Aged Male Osteoporosis

Enobosarm (ostarine, MK-2866, or GTx-024) is a non-steroidal selective androgen receptor modulator. This study evaluated the effect of various regimens of enobosarm (EN) on bone healing in an orchiectomized rat model for aged male osteoporosis and compared it to testosterone (T) treatment. Ninety eight-month-old male Sprague Dawley rats were either orchiectomized (Orx) or left intact (Non-Orx) and divided into groups (n = 15/group): (1) Non-Orx; (2) Orx; (3) Orx+T-th; (4) Orx+EN-th; (5) Orx+T-pr; and (6) Orx+EN-pr. Prophylaxis (Pr) treatments were applied immediately after Orx for up to 18 weeks. Therapy (Th) treatments were applied 12 weeks after Orx for up to 6 weeks. Bilateral tibia osteotomy with plate osteosynthesis was performed 12 weeks after Orx in all groups. EN and T were mixed with the diet; the daily dosage was 0.35 ± 0.06 and 41 ± 8 mg/kg BW, respectively. Both T treatments improved bone healing by increasing callus volume and area, bone volume and density, and cortical width; they had no effect on prostate or levator ani weight. EN-pr increased the callus area and callus density and decreased cortical density, but increased prostate weight. The effect of T-pr and T-th on bone was stronger than EN-pr. EN-th affected bone healing negatively by reducing callus density and area and delaying osteotomy bridging. Levator ani weight was increased in both EN groups. EN treatment after fracture is not advisable in aged males. EN-pr treatment as a therapy for bone healing in men could be further investigated; endocrinological side effects must be closely monitored.

Impact of Dehydroepiandrosterone (DHEA) on Bone Mineral Density and Bone Mineral Content in a Rat Model of Male Hypogonadism

Objectives: The present study examined the effect DHEA (dehydroepiandrosterone) on bone mineral content (BMC) and bone mineral density (BMD) and biomarkers of bone remodeling in orchidectomized male rats. Material and Methods: A total of 32 male rats were divided equally into four groups (n = 8): (i) control group (C), (ii) control treated with DHEA (Control + DHEA), (iii) orchidectomized (ORCH) group that underwent bilateral orchidectomy and (iv) orchidectomized (ORCH) rats treated with DHEA (ORCH+DHEA). DHEA treatment started 4 weeks after orchidectomy and continued for 12 weeks. After 12 weeks the bone mineral density (BMD) and bone mineral content (BMC) were assayed in the tibia and femur of the right hind limb of each rat. We also measured the serum levels of the bone turnover markers deoxypyridinoline (Dpd), N-telopeptide of type I collagen (NTx), alkaline phosphatase (ALP), tartrate-resistant acid phosphatase 5b (TRAP-5b) and osteocalcin (OC) as well as receptor activator of nuclear factor kappa B (RANK) and osteoprotegerin (OPG). Results: Orchidectomy in rats caused significant reduction in BMD, BMC, serum levels of testosterone, PTH (parathyroid hormone), OPG, OC and ALP with significant rise in serum levels of TRAP-5B, RANK, Dpd and NTx1 (p < 0.05). On the other hand, DHEA therapy for 12 weeks caused significant improvement in all studied parameters except NTx1 (p < 0.05). Conclusions: DHEA corrected hypogonadism-induced osteoporosis in male rats probably via inhibiting osteoclastogenesis, stimulating the activity of osteoblasts and stimulating the secretion of PTH and testosterone.

Dihydrotestosterone and 17-Estradiol Enhancement of in vitro Osteogenic Differentiation of Castrated Male Rat Bone Marrow Mesenchymal Stem Cells (rBMMSCs)

Background: In vitro impact of dihydrotestosterone (DHT) and 17-estradiol (E2) in osteogenic differentiation of castrated rat bone marrow mesenchymal stem cells (rBMMSC) still need to be clarified. Materials and Methods: The viability, proliferation and density of cultured rBMMSC isolated from sham operated (Sham) and castrated (Cast) male rats were evaluated. rBMMSC were cultured with osteogenic differentiating medium (ODM) in the presence of DHT (5,10 nM) and E2 (10,100 nM). Osteogenesis was evaluated by alizarin red staining and measurement of calcium deposition and bone alkaline phosphatase (B-ALP) activity. Results: Population doubling (PD) of rBMMSC isolated from Cast rats was significantly lower (P<0.05) compared to that isolated from Sham rats. rBMMSC from Cast rats showed low scattered calcified nodule after culturing in ODM and did not cause a significant increase in calcium deposition and B-ALP activity compared to rBMMSCs from Sham rats. Exposure of rBMMSC isolated from Cast rats to DHT (5 nM) or E2 (10 nM) in ODM showed medium scattered calcified nodules with significantly higher (P<0.05) calcium deposition and B-ALP activity. Moreover, exposure of rBMMSC to DHT (10 nM) or E2 (100 nM) showed high scattered calcified nodules with higher (P<0.01) calcium deposition and B-ALP activity Conclusion: These results indicated that the presence of testes might participate in controlling the in vitro proliferation and osteogenic differentiation capacity of rBMMSCs. DHT and E2 can enhance the osteogenic capacity of rBMMSCs in a dose-dependent manner. Based on these observations, optimum usage of DHT and E2 can overcome the limitations of MSCs and advance the therapeutic bone regeneration potential in the future.

Changes in Bone Metabolism in Young Castrated Male Rats

PURPOSE

To determine the window of time during which osteoporosis affects the management of spinal surgery and the mechanism of bone metabolism changes in males with osteoporosis by examining changes in bone metabolism in young castrated male rats.

MATERIALS AND METHODS

A total of 30 Sprague-Dawley rats were randomly allocated into two study groups. Group 1 (control) received a sham surgery and Group 2 received bilateral orchiectomy to change bone mineral density (BMD). Serum osteocalcin, alkaline phosphatase (ALP), and collagen type 1 cross-linked C-telopeptide (CTX) were analyzed at postoperative date (POD) 8, 10, and 12 weeks. BMDs were measured using micro computed tomography scans.

RESULTS

Femoral and lumbar BMDs were decreased in the orchiectomy groups. BMDs in the sham and orchiectomy groups showed statistically differences at POD 8, 10, and 12 weeks for the femur (p=0.032, 0.008, 0.008) and lumbar spine (p=0.151, 0.008, 0.008, respectively). Serum osteocalcin, ALP, and CTX decreased gradually; however, N-terminal type 1 procollagen (P1NP) showed a slight increase yet no significant change.

CONCLUSION

In young castrated male rats, a significant decrease in BMD was observed after orchiectomy due to the mixture of two detrimental factors. Young castrated male rats did not reach peak BMD. Increased bone turnover causes bone resorption to exceed bone formation. This study may contribute to the creation of a valuable model for studies of male osteoporosis and the spinal surgery field.