Korean J Physiol Pharmacol.
1997 Feb;1(1):91-96.
Lipocortin 1 mediates the suppressive effects of dexamethasone on
CoNinduced proliferative response and nitric oxide production in rat
splenic leukocytes
- Affiliations
-
- 1Departments of Physiology, University of Ulsan College of Medicine
, Ulsan South Korea.
Abstract
-
Lipocortin 1 has been proposed as a putative mediator of
anti-inflammatory actions of glucocorticoids. We investigated the role
of lipocortin 1 in the effect of dexamethasone using rat splenic
leukocytes. Concanavalin A(ConA; 1-microgram/ml) increased the leukocyte
proliferation and nitric oxide(NO) generation, which were measured as
(3H)-thymidine uptake by the cells and nitrite accumulation in the
culture media, respectively. Dexamethasone suppressed CoNinduced cell
proliferation, in a concentration-dependent manner with EC-50 around
50nM. The addition of anti-lipocortin 1 (Anti-LC1) reversed
dexamethasone effects: 0.24, 1.2, 6 microgram/ml of Anti-LC1 reversed
dexamethasone(50nM)-induced suppression of thymidine uptake by 9+/-3%,
16+/-3%, 36+/-5%, respectively; 0.24, 1.2, and 6-microgram/ml of Anti-LC1
reversed dexamethasone-induced decrease of nitrite concentration by 49
+/- 16%, 61 +/- 20%, 77 +/- 19 %, respectively. The present data indicate
that lipocortin 1 mediates, at least in part, glucocorticoids-induced
suppression of leukocyte proliferation and blockade of NO generation.