| Autor: |
Schaefer HI; Department of Cardiology, University Hospital, Leiden, The Netherlands., Höld KM, Egas-Kenniphaas JM, van der Laarse A |
| Jazyk: |
angličtina |
| Zdroj: |
Cell calcium [Cell Calcium] 1993 Jun; Vol. 14 (6), pp. 507-16. |
| DOI: |
10.1016/0143-4160(93)90009-u |
| Abstrakt: |
The effect of lipoproteins on cellular calcium ion concentration ([Ca2+]i) in EA.hy 926 endothelial cells was investigated, particularly with respect to the difference in response on [Ca2+]i between native low-density lipoprotein (LDL) which binds to the apo B/E receptor, and acetylated LDL (AcLDL) which binds to the scavenger receptor. The scavenger receptor recognizes chemically or cell-induced modified LDL. LDL as well as AcLDL caused a transient increase of [Ca2+]i lasting 1-2 min. On a protein basis, LDL was more effective that AcLDL in raising [Ca2+]i. Preincubation of confluent cultures in growth medium with a reduced fetal bovine serum content (2% FBS instead of 10%) increased the potency of LDL to increase [Ca2+]i. The LDL-induced peak [Ca2+]i was dependent on cell density. The effect of AcLDL on [Ca2+]i did not differ between confluent and nonconfluent cultures. Also, preincubation with 2% FBS did not modify the AcLDL-induced calcium response. We conclude that binding of lipoproteins to membrane lipoprotein receptors is responsible for the transient rise of [Ca2+]i although the characteristics of the calcium response are dependent on the receptor involved, i.e. the apo B/E (LDL) receptor or the scavenger receptor. We suggest that Ca2+ acts as a second messenger, and that the LDL-induced calcium response is controlled by the proliferative state of the cells. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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