Mechanism of inhibition of prostaglandin biosynthesis by hydrocortisone in rat leucocytes.

Hydrocortisone (10 microgram/ml) greatly inhibits the prostaglandin release by rat peritoneal leucocytes phagocytosing killed bacteria. The inhibition, which occurs after an initial latency of 30 min, is completely reversed by either actinomycin D (0.5 microgram/ml) or cycloheximide (1 microgram/ml). Since these antibiotics are known inhibitors of DNA-dependent RNA synthesis and protein synthesis respectively, it appears that the mechanism of inhibition of prostaglandin biosynthesis by hydrocortisone in rat leucocytes involves stimulation of transcription and induction of protein synthesis.