BACKGROUND:The OPG-RANKL-RANK transport system plays a crucial role in bone resorption mechanism of osteoclasts. OBJECTIVE:To observe the expression of OPG-RANKL-RANK signaling system in osteoclasts, osteoporosis, and the targeted therapy of OPG-RANKL-RANK signaling system. METHODS:We retrieved related literatures in the periodicals database with the key words of“osteoprotegerin, RANKL, RANK, osteoclasts, osteoporosis”in English and Chinese. According to the inclusion criteria, the literatures were included in this study after the evaluation of quality. RESULTS AND CONCLUSION:The mature of osteoclasts is mediated via OPG-RANKL-RANK signaling system and its associated signaling pathways. This signal pathway leads to the mechanism of osteoporosis. At the genetic and molecular levels, the targeted therapy of osteoporosis has become the focus. OPG-RANKL-RANK signaling system can provide a research platform for targeted treatment of osteoporosis, and OPG-RANKL-RANK signaling system is an important way to the regulation of osteoclasts and osteoporosis.

BACKGROUND:The V-ATPase a3 transport system plays a crucial role on bone resorption mechanism of the osteoclasts.
OBJECTIVE:To observe the expression of V-ATPase a3 transport system in fracture repair and the effect of V-ATPase a3 transport system inhibitor on fracture healing.
METHODS:We retrieved related literatures in the periodicals database with the key words, and screen them according to the inclusion criteria. The literatures were included in this study after the evaluation of quality.
RESULTS AND CONCLUSION:V-ATPase a3 transport system widely exists in the cytoplasm membrane and organel e membrane of eukaryotic cells. V-ATPase a3 has two structural domains:V0 and V1. V0 structural domain is the proton transport channel, V1 structural domain is mainly the hydrolysis of ATP. V-ATPase a3 transport system focuses on the fril ed edge of osteoclasts, H+is transported to form a high concentration, dissolves inorganic minerals and provides the acidic environment for hydrolytic enzymes, thus being involved in bone resorption. So V-ATPase a3 transport system is selected as the research target in the fracture repair and reshape.

The aim of the study was to prepare enrofloxacin nanosuspension injection and evaluate its pharmacokinetics after giving a single intramuscular injection.The high pressure homogeneous technique was used to prepare enrofloxacin nanosuspension injection and preliminary evaluation of the quality was done.The high performance liquid chromatography (HPLC) method was used to determinate content of enrofloxacin in pig plasma.And the pharmacokinetic characteristics of enrofloxacin nanosuspension injection were compared with Baytril injection.The content of enrofloxacin in this preparation is 97.9％.The average particle size of enrofloxacin nanosuspension injection was (613.21±5.78) nm,PDI was (0.22±0.02) and the potential was-2.02 mV.Maximal plasma concentrations were (0.32±0.12) and (0.67 ± 0.09) mg/L after i.m administration with enrofloxacin nanosuspension injection and Baytril injection.The peak times were (2.88 ±0.96) and (0.79±0.26) hours,respectively.Mean elimination half-lifes were (5.99± 1.37) and (4.49 ± 1.25) hours,respectively.Areas under concentration-time curve were (4.63±1.30) and (4.40±0.45) mg/L · h,respectively.Mean residence times were (9.59±2.34) and (5.41±1.10) hours,respectively.The relative bioavailability of enrofloxacin nanosuspension injection was 105.2％.The preparation method of high pressure homogeneous was simple and good reproducibility.Enrofloxacin nanosuspension injection was characterized by non-sedimentation,easy-redispersion,relatively stable.Comparing with Baytril injection,enrofloxacin nanosuspension injection had a certain slowrelease effect,showing slower elimination than enrofloxacin injeetion.