[Effects of corticosteroid on porcine retinal pigment epithelial cells in culture--2. Effects on phagocytosis and lysosomal activity].
OBJECTIVE
The effects of a corticosteoid on the phagocytosis and lysosomal activity of cultured porcine retinal pigment epithelium (RPE) cells were investigated.


METHODS
After exposing cultured RPE cells to various concentrations (10, 50, 100, 500, 1,000 nM) of betamethasone sodium phosphate (betamethasone), the cells were incubated with latex microspheres for 6 hours.


RESULTS
The number of latex microspheres phagocytized by the cultured RPE cells was inhibited by 50 nM betamethasone within 24 hours. Ten-nM betamethasone did not inhibit the proliferation of cultured RPE cells, but ingestion of latex microspheres by the cells was inhibited after 3 days. Lysosomal activity (acid phosphatase, beta-glucuronidase) of RPE cells was inhibited by a high concentration (500 nM) of betametasone.


CONCLUSIONS
These results suggest that corticosteroid inhibits the phagocytosis and lysosomal activity of cultured RPE cells.
Kawahara
S
S
Department of Ophthalmology, Kansai Medical University, Moriguchi, Japan.
Kishimoto
N
N
Sugasawa
K
K
Uyama
M
M
D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D001623:Betamethasone / Q000494:pharmacology*; D002478:Cells, Cultured; D005966:Glucuronidase / Q000378:metabolism; D008247:Lysosomes / Q000187:drug effects* / Q000201:enzymology*; D010587:Phagocytosis / Q000187:drug effects*; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D013552:Swine
D001623:Betamethasone; D000135:Acid Phosphatase; D005966:Glucuronidase