[Anti-inflammatory effect of ACTH in the rat]

In rats, ACTH reduced the oedemas induced by zymosan and lambda carrageenan. ACTH reduced the volume of the exudate induced by sponge implantation and its content in proteins, beta-galactosidase, beta-glucuronidase and PGE2. The inhibitory effect of ACTH was suppressed by adrenalectomy which increased the carrageenan-oedema. The inhibitory effect of ACTH was also suppressed by 17 alpha-methyltestosterone. Corticosterone reduced carrageenan-oedema. The inhibitory effect of corticosterone was suppressed by cycloheximide and actinomycin D. These results suggest that rat adrenal steroids, among which corticosterone, can modulate the reactivity of the animal towards irritating processes. The anti-inflammatory effect of rat adrenal steroids would depend on the formation of lipocortin-like peptides.