Fig. 2From: Prolactin blocks the expression of receptor activator of nuclear factor κB ligand and reduces osteoclastogenesis and bone loss in murine inflammatory arthritisProlactin (PRL) reduces loss of trabecular bone area and osteoclastogenesis in polyarticular adjuvant-induced arthritis (AIA). Osmotic minipumps delivering PRL were positioned (or were not positioned) 3 days before the intradermal injection of complete Freund’s adjuvant (CFA) to induce AIA in rats. The experiments ended on day 21 after injection of CFA, when all evaluations were performed. a Representative images of hematoxylin-eosin-stained tibiotarsal joint sections. Scale bar 500 μm. Ep epiphyseal plate, Bm bone marrow, Ct cortical bone, Tb trabecular bone, c cartilage, sm synovial membrane. Graph indicates the values of trabecular bone area (trabecular surface area divided by the total bone area). b Representative images of tartrate-resistant alkaline phosphatase (TRAP)-stained tibiotarsal joint sections where TRAP-positive purple spots (multinucleated cells (osteoclasts)) below the growth plate are indicated (arrows). Scale bar 200 μm. Graph shows the number of osteoclasts per bone surface (N.Oc/BS). c Quantification by quantitative real-time PCR (qRT-PCR) of the mRNA levels of the osteoclast gene markers: Trap, Mmp9, Ctsk, and Tnfrsf11a in the ankle joints. d qRT-PCR quantification of the mRNA levels of Tnfrsf11 and Tnfrsf11b and of the Tnfrsf11/Tnfrsf11b mRNA ratio in the ankle joints. Values are means ± SEM (n = 5–8). *P < 0.05, **P < 0.01, ***P < 0.001, n.s. non-significantBack to article page