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001-es BibID:BIBFORM042088
Első szerző:Varga R.
Cím:Responses Of The Tibial Microcirculation To Local Iontophoretic Treatment For Osteopenia In Rats / Varga R., Szabó A., Gomez I., Jánvári K., Varga G., Pap L., Boros M.
Megjegyzések:Introduction: Accidental bone rupture is a frequentconsequence of bone demineralization in elderly patients. Inthe present study, bone repair was investigated inosteoporotic female Sprague-Dawley rats. Electrophoretictransfer of calcium and phosphate ions was applied in orderto rebuild calcium-hydroxi-fluoro-apatite content of the tibia.Periosteal microcirculatory reactions were compared in 3-month-old intact (n=6) and 14-month-old animals that wereovarectomized (n=10) or sham-operated (n=5) and treatedwith iontophoresis.Methods: Bilateral ovarectomy was performed in 3-montholdrats under ketamine/xylazine anesthesia and thedevelopment of bone loss was non-invasively monitored withultrasonic densitometry. At the age of 8 months,iontophoresis (anterior anode: calcium, posterior cathode:phosphate; at 1.5V; 0.8 mA) of the left hind limbs wasinitiated and repeated 5 times within 3 weeks; bone densitywas monitored in parallel. 6 months later, anterior tibialsurfaces of both legs were exposed for analysis of themicrocirculation. The OPS technique (Cytoscan A/R) wasused to assess the microvascular density of the periosteumand fluorescence intravital videomicroscopy for theevaluation of inflammatory reactions in response to 60 minischemia and 180 min reperfusion. Soft tissue biopsies (skin,muscle) and bone samples were taken for mass spectrometricanalysis (calcium content) and bone braking tests,respectively.Results: Osteopenia developed within 21 weeks afterovarectomy (ultrasonic AD-SOS values decreased from1850?101 to 1674?33). A single iontophoretic treatmentrestored normal bone density of the tibia for 4 days only, butwhen the treatment was repeated 5 times the effects persistedand the bone density was elevated for 6 months until thesacrifice of the animals. Iontophoresis also elicited anincrease in bone density of the sham-operated animals (to2019?35). The treatment did not affect the microvasculararchitecture of the periosteum or baseline microcirculatorycharacteristics of the tibia. Ischemia followed by reperfusionslightly increased rolling of neutrophil leukocytes, butsignificantly increased leukocyte sticking in postcapillaryvenules of ovarectomized animals at 120 min and 180 min ofreperfusion (from 302?4 1/mm? to 697?7 1/mm? and 709?101/mm?, respectively). Tibias subjected to iontophoresisshowed similar changes and these variables did not differedfrom those found in young adults or in sham-ovarectomizedlittermates. Mass spectrometric analysis revealed a significantcalcium deposition in the bone, but not in the soft tissues. Thebraking force of the osteoporotic tibias decreased by 46%, butincreased by approx. 30% over the baseline level afteriontophoresis.Conclusion: Calcium-phosphate iontophoresis causespersistent bone remineralization and restores local boneendurance without causing microcirculatory complications.The tibial microcirculation of young, old, ovarectomized oldfemale rats, and those which received iontophoretictreatments displays similar degree of inflammatory reactionsin response to ischemia/reperfusion. The results suggest thationtophoresis may represent a novel adjuvant treatmentmodality for local osteoporotic symptoms.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idézhető absztrakt
Megjelenés:European Surgical Research. - 38 : Suppl.1 (2006), p. 51-52. -
További szerzők:Szabó A. (Szeged) Gomez Izabella (1981-) (orvos) Jánvári Kristóf Varga G. Pap L. Boros Mihály (Szeged)
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