PROLONGATION OF DIOESTRUS IN THE MOUSE AS A QUANTITATIVE ASSAY OF LUTEOTROPHIC ACTIVITY OF PROLACTIN

Abstract

SUMMARY: A method has been developed for the quantitative assay of luteotrophic activity of prolactin using the prolongation of dioestrus in mature virgin mice as the end-point of the effect. The assay is based on the principle of an 'all-or-none' response and criteria for a positive result have been specified. A modified parallel line assay has been used with three doses each of the standard and of the unknown. Four different preparations of prolactin have been tested using bovine prolactin, Armour Laboratories, Lot no. D14083–2B as the reference preparation. The assay is not specific, but it may be used for quantitative measurement of the luteotrophic activity of purified preparations of prolactin.