Endocrinological Aspects of Avidin Formation in the Avian Oviduct

Abstract
Both DCA and testosterone propionate induced avidin formation in previously estrogenized chicks, DCA being as effective as progesterone. Testosterone was effective at a higher daily dose. The lack of specificity in response to steroids agrees with other such endocrine reactions. Progesterone plus stilbestrol were injected and the latent period for avidin appearance in the oviduct detd. Avidin appeared after 2 hrs., reaching a high titre in 4-8 hrs. It increased with progesterone whether stilbestrol was administered simultaneously or not. Increasing estrogen levels elevated the avidin titre if estrogen were given together with progesterone. There is no evidence of decisive antagonism between estrogen and progesterone.