Gender-Specific effects of L-arginine supplementation on bone mineral density and trabecular bone volume in Sprague-Dawley rats; stereological study

Abstract

Background

L-arginine (Arg) is a semi-essential amino acid that can be used as a key mediator for the release of growth hormone (GH), insulin-like growth factor-1(IGF-1), and other growth factors. In this study, we comprehensively evaluated the effect of Arg intake on bone growth and associated markers.

Methods

The study involved 24 Sprague-Dawley rats (12 males, 12 females) divided into two groups (Age = 24 days). One group received a standard diet, while the other was injected with 10 mg/kg of Arg daily for 90 days. Serum bone markers like calcium (Ca), phosphorous(P), and alkaline phosphatase (ALP) were analyzed via colorimetric assays. stereological study and bone mineral density (BMD) were conducted via dissector method and Hologic Dual-energy x-ray absorptiometry (DXA) system; respectively.

Results

Biochemical assays showed no significant differences in Ca, P, and ALP levels between groups. Male rats in the case group exhibited lower testosterone levels (p.value = 0.009). Stereological and bone mineral density (BMD) analyses revealed contrasting gender-specific outcomes. Female rats in the case group had higher BMD (p.value = 0.001), while males had lower BMD compared to controls (p.value = 0.018). Arg consumption affects trabecula volume values differently in females compared to males (p.value = 0.022). Furthermore, the study observed decreased osteocytes and osteoblasts in male case rats. The gender-based differences in BMD were attributed to Arg’s paradoxical impact on testosterone levels in males.

Conclusion

Overall, Arg supplementation was found to influence BMD and trabecular bone volume, with outcomes varying depending on gender. The study highlights the intricate interplay between Arg, sex hormones, and bone health, offering insights into these complex relationships.