Novel ultrastructural features as revealed by phthalocyanine reactions indicate cell priming for calcification in subdermally implanted aortic valves.
The roles played by various determinants in physiological, pathological or experimental calcification are still unclear. In this investigation, new insights were gained into structural changes occurring in porcine aortic valves undergoing mineralization in the rat subdermal model and then subjected to reactions with cationic phthalocyanines (PHTs), at salt-critical electrolyte concentrations (CEC). PHT reactions showed decalcifying effects, depending on both acidic pH in the media employed and mineral substitution by Cuprolinic Blue (CB) itself, as well as specific reactivity which enabled the ultrastructural detection of unusual, PHT-positive layers (PPLs) encircling cells and matrix vesicles, at 0.05 M CEC conditions. Other reactions at different CEC conditions, or subsequent to enzymatical or specific extractive treatments, suggest PPL appearance is due to PHT uptake by clustered anionic phospholipids, which seem to be involved in mineral precipitation. PPLs present as a novel, reliable ultrastructural parameter indicating cell propensity in priming experimental and, possibly, pathological calcification.
Department of Medical and Morphological Research, University of Udine, Piazzale Kolbe 3, I-33100, Udine, Italy. fulvia.ortolani@uniud.it
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Ortolani
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Petrelli
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Tubaro
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Spina
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Marchini
D000818:Animals; D001021:Aortic Valve / Q000473:pathology / Q000637:transplantation* / Q000648:ultrastructure*; D002114:Calcinosis / Q000503:physiopathology*; D002614:Chelating Agents; D020405:Dermis / Q000378:metabolism / Q000601:surgery / Q000648:ultrastructure; D004195:Disease Models, Animal; D005109:Extracellular Matrix / Q000378:metabolism / Q000648:ultrastructure; D006085:Graft Survival / Q000502:physiology*; D006350:Heart Valve Prosthesis / Q000592:standards*; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007211:Indoles; D054833:Isoindoles; D008297:Male; D008854:Microscopy, Electron; D009942:Organometallic Compounds; D051381:Rats; D017207:Rats, Sprague-Dawley; D013552:Swine
D002614:Chelating Agents; D007211:Indoles; D054833:Isoindoles; D009942:Organometallic Compounds; C015445:copper phthalocyanine; C013647:phthalocyanine