Cell cycle-specific effects of glucocorticoids on phytohaemagglutinin-stimulated lymphocytes.

摘要: Effects of steroid hormones and colchicine on the response pig lymphocytes to phytohaemagglutinin (PHA) were assessed by measurement [6-3H]thymidine incorporation. At concentrations 1 microM below, only glucocorticoids progesterone inhibited PHA-stimulated incorporation but at 100 inhibition was also produced oestrogens, androgens physiologically inactive steroids. Measurement 18-24 hr, 6-12 hr or 0-6 after delayed addition synthetic glucocorticoid, dexamethasone, revealed a succession alternating phases sensitivity insensitivity effects which suggested that it acting, perhaps indirectly, in cell cycle stage-specific manner arrest progression activated from G1 S. Similar observed with colchicine, 11-epicortisol non-cycle-specific manner. Glucocorticoid receptor levels increased 2-5-fold within 24 PHA stimulation.