Failure of Oxytocin to stimulate the Pigeon Crop Gland

Abstract

IT is well known that the crop gland of the pigeon proliferates and increases in weight in response to prolactin. This effect of prolactin on the crop gland has been used as a qualitative and quantitative assay for this hormone¹. Recently, Chaudhury and Chaudhury² threw doubt on the specificity of action of prolactin on the pigeon crop gland by claiming that intradermal injections over the crop sac or systemic administration of oxytocin produced increases in crop-weight. This contradicts the earlier work of Riddle and Bates¹, who reported that posterior pituitary hormones had no effect on the pigeon crop gland. Chaudhury and Chaudhury² also suggested that oxytocin may induce a release of prolactin in pigeons, which is similar to the hypothesis of Benson and Folley³ in rats. They did not indicate whether typical crop sac proliferation was seen in the pigeons.