Characterization of rat heart alkaline phosphatase isoenzymes and modulation of activity

• Type: Article in International Scientific Journal
• Date: 2008

Authors

Mota, A (Author) Other; Silva, P (Author) Other; Neves, D (Author) Other; Lemos, C (Author) Other; Calhau, C (Author) FMUP; Torres, D (Author) FCNAUP; Martel, F (Author) FMUP; Fraga, H (Author) Other; Ribeiro, L (Author) FMUP; Alcada, MNMP (Author) FMUP; Pinho, MJ (Author) FMUP; Negrao, MR (Author) FMUP; Pedrosa, R (Author) Other; Guerreiro, S (Author) Other; Guimaraes, JT (Author) FMUP; Azevedo, I (Author) Other; Martins, MJ (Author) FMUP

Journal

Title: Brazilian Journal of Medical and Biological Research

Vol. 41 No. 7

Pages: 600-609

ISSN: 0100-879X

Publisher: Associacao Brasileira de Divulgacao Cientifica

Indexing

ISI Web of Knowledge - 15 Citations

ISI Web of Science

Scopus - 19 Citations

Pubmed / Medline

Scientific classification

FOS: Medical and Health sciences > Other medical sciences

CORDIS: Health sciences

Other information

Authenticus ID: P-003-XX7

DOI: 10.1590/s0100-879x2008000700009

Abstract (EN): 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 p-nitrophenol 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 p-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 L-phenylalanine, 100 mu L polyphenol-rich beverages and 0.5 mM progesterone (24, 21 to 29 and 11%, respectively). beta-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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10