PROLACTIN ASSAY BY A COMPARISON OF THE TWO CROP-SACS OF THE SAME PIGEON AFTER LOCALINJECTION11,

Abstract

A 20% change in dosage was detected in the 8 crop-sacs of 4 birds in both 2 and 4 day tests. A 100% dosage change was not uniformly detected by level of response detns. in groups of birds. The following 2 factors in the adm. of prolactin solns. were found to affect the response significantly: location on the skin of the injection site with respect to the underlying crop-sac; and the volume of the soln. injected. Nearly equal responses were elicited following both subcut. and intradermal adms. The 2 following factors in the prep. of pituitary tissue affected the response significantly: the use of suspensions of either acetone dried or fresh tissues instead of extracts of the tissue, and acetone desiccation. The volume of extracting fluid was not a factor affecting the response. Two samples of acetone dried pituitary tissue, one of which was half as potent in prolactin as the other, were not distinguishable when administered as suspensions but gave the expected comparative responses when administered as extracts. Pituitary prolactin potencies for several spp. were 5-10 times that reported by the Missouri laboratory. The probable reasons for lack of better agreement are discussed.