Characterization of rat heart alkaline phosphatase isoenzymes and modulation of activity.
ABSTRACT Alkaline phosphatase (ALP) is important in calcification and its expression seems to be associated with the inflammatory process. We investigated the in vitro acute effects of compounds used for the prevention or treatment of cardiovascular diseases on total ALP activity from male Wistar rat heart homogenate. ALP activity was determined by quantifying, at 410 nm, the pnitrophenol released from p-nitrophenylphosphate (substrate in Tris buffer, pH 10.4). Using specific inhibitors of ALP activity and the reverse transcription-polymerase chain reaction, we showed that the rat heart had high ALP activity (31.73 ± 3.43 nmol nitrophenol·mg protein-1·min-1): mainly tissue-nonspecific ALP but also tissue-specific intestinal ALP type II. Both ALP isoenzymes presented myocardial localization (striated pattern) by immunofluorescence. ALP was inhibited a) strongly by 0.5 mM levamisole, 2 mM theophylline and 2 mM aspirin (91, 77 and 84%, respectively) and b) less strongly by 2 mM Lphenylalanine, 100 μL polyphenol-rich beverages and 0.5 mM progesterone (24, 21 to 29 and 11%, respectively). ß-estradiol and caffeine (0.5 and 2 mM) had no effect; 0.5 mM simvastatin and 2 mM atenolol activated ALP (32 and 36%, respectively). Propranolol (2 mM) tended to activate ALP activity and corticosterone activated (18%) and inhibited (13%) (0.5 and 2 mM, respectively). We report, for the first time, that the rat heart expresses intestinal ALP type II and has high total ALP activity. ALP activity was inhibited by compounds used in the prevention of cardiovascular pathology. ALP manipulation in vivo may constitute an additional target for intervention in cardiovascular diseases.
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ABSTRACT: The main objective of this study is to demonstrate the application of strategy of an experiment design to optimize the compressive strength and setting time of zinc phosphate cement used in the dental application. For this work, the extreme vertices design was chosen. Its factors are components of the mixture forming a ternary system: zinc oxide, aluminum phosphate and orthophosphoric acid (ZnO–AlPO4–H3PO4). The local region of dental cement – in simplex space- explored and limited by upper and lower limits of the three components of the mixture. The optimization of each response and then all together by graphical methods allowed us to obtain the adequate cement.Arabian Journal of Chemistry 07/2012; · 2.27 Impact Factor
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ABSTRACT: The aim of this study was to test the applicability of multipotent maxillary cells (MMC) for cell therapy concepts and to evaluate their in vitro behaviour on two different bone substitutes. Cells isolated from maxillary bone from 10 donors were expanded using media containing human platelet lysate (HPL) replacing foetal bovine serum and differentiated towards both the osteogenic and the adipogenic lineage. Surface markers were determined by fluorescence-activated cell sorting analysis. Calcium deposits, alkaline phosphatase (ALP) and osteocalcin (OC) were used as biomarkers of osteogenic differentiation. Oil Red O was used to verify adipogenic differentiation. The osteogenic lineage and undifferentiated controls were further cultured on natural bone mineral of bovine origin (BioOss) and beta-tricalcium phosphate (Vitoss) scaffolds. Scaffold efficacy and cell migration were evaluated with live cell imaging. Isolated cells presented characteristics of bone marrow (BM)-stromal cells and could easily be expanded to clinical scales. Cells expressed osteogenic and adipogenic markers when cultured with inductive media. There were no obvious differences in cell migration and growth behaviour between the two bone substitutes, but significantly higher OC expression was observed on BioOss scaffolds. Both osteogenically differentiated and undifferentiated cell lines expressed ALP activity on the scaffolds. Isolated maxillary cells demonstrate multipotent in vitro characteristics comparable with those of BM-stromal cells. HPL can predictably be used for clinical-scale expansion of MMCs. Both grafting materials provide potential carrier characteristics when loaded with MMCs.Clinical Oral Implants Research 07/2010; 21(7):699-708. · 3.43 Impact Factor
- Journal of Pharmaceutical Technology & Drug Research. 01/2013;