THE INFLUENCE OF ESTRADIOL ON THE COMPOSITION AND RESPIRATION OF OVIDUCT TISSUE IN THE IMMATURE CHICK

Abstract

Estrogen administration to the immature fowl, to give oviduct growth rates comparable to those found in the pullet prior to the onset of egg-laying was studied. In a preliminary experiment the level of estradiol required to induce such a growth response in six-week-old chicks was found to be more than 2 mg. administered over a 10-day period. Maximal growth response was produced by 10 mg. estradiol. Two experiments are described in which two levels of estradiol giving growth responses dependent on dose level, i.e. 0.75 mg. and 1.5 mg., are compared with a level of 10 mg. giving maximal response. Oviduct tissues from these experiments were examined for their respiration rate, moisture, protein, fat, pentosenucleic acid and deoxypentosenucleic acid contents, and alkaline phosphatase activity. Moisture content of the tissue decreased with increasing hormone treatment. Fat content increased and on a fresh tissue basis so did protein content. Hypertrophy resulting from 10 mg. estradiol increased the ratio of pentosenucleic acid to deoxypentosenucleic acid, but decreased the respiration rate and alkaline phosphatase activity which were stimulated by 1.5 mg. estradiol.