PROGESTERONE-INDEPENDENT AVIDIN INDUCTION IN CHICK-TISSUES CAUSED BY TISSUE-INJURY AND INFLAMMATION

Progesterone was administered to oestrogen-treated and untreated chicks, or inflammation in the abdominal cavity was caused by intestine and liver injury or intraperitoneal actinomycin D administration. Local injury to the pectoral muscle was also carried out. Chicks were killed 24-26 h after the treatment and the biotin-binding egg white protein, avidin, was assayed in a number of tissues using a [14C]biotin-binding method and radioimmunoassay. Ovalbumin was also assayed with a radioimmunoassay. Avidin was not found in the tissues of control chicks. Progesterone induced avidin only in the oviducts of oestrogen-treated chicks. After intestine and liver injury avidin was found, however, in all the tissues of oestrogen-treated and untreated chicks studied except for the brain. The concentrations were highest in the oviduct, lung, intestine and bursa of Frabicius. Actinomycin D (200 μg/kg) caused ascites and subcutaneous oedema in 40-60% of the chicks, and avidin was found only in the tissues of these inflamed animals. Avidin production caused by the local muscular injury was restricted to the injured area. Tissue injury and inflammation did not induce ovalbumin in any tissue. The study shows that avidin can be induced besides the oviduct also in non-oviductal chick tissues, and it is proposed that there are both progesterone-dependent and -independent avidin induction mechanisms.