Regulation of lipoprotein lipase by dibutyryl cAMP, cholera toxin, Hepes and heparin in F1 heart-cell cultures.
Biochim Biophys Acta
; 1137(2): 237-41, 1992 Oct 27.
Article
em En
| MEDLINE
| ID: mdl-1384715
ABSTRACT
Regulation of lipoprotein lipase was studied in mesenchymal rat heart-cell cultures. Treatment of the cultures with dibutyryl cyclic AMP or with cholera toxin resulted in an increase in LPL activity and a comparable increase in LPL mRNA. When the cells were exposed to 100 mM Hepes for 24 h, total enzyme activity rose 2-fold and LPL mRNA increased 2.4-fold. After 72 h, there was a 3-fold increase in LPL mRNA and a 4-fold rise in cellular LPL activity, while medium activity increased 20-fold. Exposure of the cultures to heparin for 24 h resulted in a 3.2-fold increase in total activity and a 36-fold increase in medium activity. This increase was not accompanied by any rise in LPL mRNA. Addition of actinomycin D to control dishes for 24 h resulted in a 33% reduction in LPL mRNA and a 43% reduction in enzyme activity. These values were 71% and 56%, respectively, in Hepes-treated cells, indicating that no stabilization of LPL mRNA occurred under these conditions. It can be concluded that in mesenchymal rat heart-cells in culture cAMP and cholera toxin upregulate lipoprotein lipase at the level of transcription. The increase in LPL activity after 24 h exposure to Hepes could be compatible with transcriptional regulation, while exposure to heparin is not accompanied by a change in LPL mRNA.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Heparina
/
Toxina da Cólera
/
Bucladesina
/
HEPES
/
Lipase Lipoproteica
/
Miocárdio
Limite:
Animals
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
1992
Tipo de documento:
Article
País de afiliação:
Israel