Abstract. Specific binding of the synthetic androgen, [17α-methyl-3H]methyltrienolone, to the cytosol fraction of the submandibular salivary gland (SMG) of male mice was studied in relation to the developmental profiles of testosterone and thyroid hormones in blood. The peak rise of serum triiodothyronine (T3) at prepubertal age was closely related to both the increase of maximal androgen-binding capacity in SMG and the conspicuous surge of proliferative activity as indicated by increased rate of glandular DNA content. Also, 2-month thyroidectomized mice had an age-related, strong reduction in the number of androgen-binding sites. On the other hand, the development of the secretory functions of the gland could be better related to the rise of circulating testosterone by days 25–30 of age. The results suggest that thyroid hormones play a very important role in the early induction and further maintenance of androgen receptors in the murine SMG.
Conceicão A. S. A. Minetti, Luiz B. S. Valle, Flávio Fava-De-Moraes, João H. Romaldini and Ricardo M. Oliveira-Filho
F P Paranhos-Neto, L Vieira Neto, M Madeira, A B Moraes, L M C Mendonça, I C B Lima, C L R Chagas, D A Lira, J F Spitz, J A M Guimarães, M E L Duarte and M L F Farias
The role of vitamin D on bone microarchitecture and fragility is not clear.
To investigate whether vitamin D deficiency (25(OH)D <20 ng/mL) increases cortical bone loss and the severity of fractures.
Cross-sectional study of 287 elderly women with at least one prevalent low-impact fracture.
Biochemistry, X-rays to identify vertebral fractures (VFs) and to confirm non-vertebral fractures (NonVFs), and high-resolution peripheral quantitative computed tomography (HR-pQCT) to evaluate bone microstructure.
Serum 25(OH)D levels were associated with body mass index (BMI: r = −0.161, P = 0.006), PTH (r = −0.165; P = 0.005), CTX (r = −0.119; P = 0.043) and vBMD at cortical bone (Dcomp: r = 0.132; P = 0.033) and entire bone (D100: r = 0.162 P = 0.009) at the distal radius, but not at the tibia. Age and PTH levels were potential confounding variables, but in the multiple linear regressions only BMI (95% CI: 0.11–4.16; P < 0.01), 25(OH)D (95% CI: −0.007 to 1.70; P = 0.05) and CTX (95% CI: −149.04 to 21.80; P < 0.01) predicted Dcomp, while BMI (95% CI: 1.13–4.18; P < 0.01) and 25(OH)D (95% CI: 0.24–1.52; P < 0.01) predicted D100. NonVFs predominated in patients with 25(OH)D <20 ng/mL (P = 0.013). Logistic regression analysis showed a decrease in the likelihood of presenting grade 2–3 VFs/NonVFs for every increase in 25(OH)D (OR = 0.962, 95% CI: 0.940–0.984; P = 0.001), BMI (OR = 0.932, 95% CI: 0.885–0.981; P = 0.007) and D100 at radius (OR = 0.994, 95% CI: 0.990–0.998; P = 0.005).
In elderly patients with prevalent fractures, vitamin D deficiency was associated with cortical bone loss and severity of fractures.