Effects of glucocorticoids and disodium cromoglycate on avidin production in chick tissues.

The effects of anti-inflammatory glucocorticoids and a membrane stabilizer (disodium cromoglycate) on avidin induction were studied. Chicks were primed for 0, 3 or 7 days with diethylstilboestrol (DES; 0.5 mg/day per animal, s.c.). Actinomycin D (0.2 mg/kg, i.p.) stimulated avidin production in the oviduct, intestine, lung and wing muscle of both DES-primed and unprimed chicks. Prednisolone (5 mg/animal, i.m.) given 1 h before actinomycin D reduced the avidin amounts to control levels in the unprimed oviducts and in non-oviductal tissues. The signs of inflammation (ascites, oedema) in chicks receiving actinomycin D also disappeared with prednisolone premedication. Cortisol (50 mg/animal, i.m. or 1, 5 or 50 microgram/ml medium), prednisolone (5 mg/animal, i.m. or 0.5, 5, 10 or 50 microgram/ml medium) and dexamethasone (1 mg/animal, i.m. or 0.05 or 0.5 microgram/ml medium) stimulated avidin production in DES-primed oviducts in vivo and in vitro. Culture in vitro induced avidin production in lung and oviduct but not in wing muscle. This avidin production in culture was not inhibited by cortisol, prednisolone or disodium cromoglycate. It is concluded that actinomycin D induces avidin production through its inflammatory effect and that the induction can be prevented by anti-inflammatory glucocorticoids. It is proposed that the 'spontaneous' avidin production in culture is not the effect of trauma during tissue preparation but rather a new form of avidin induction.