抄録
A sensitive radioimmunoassay for bovine prolactin in plasma has been developed. The separation of free and antibody bound 131I labeled bovine prolactin was accomplished by the double antibody method. The method was so sensitive that unlabeled bovine prolactin as little as 0.063 mμg permitted detection of bovine prolactin in plasma as low as 2 mμg/m/ under conditions employed. Plasma from lactating cows and bovine pituitary extracts produce an identical dose response curve obtained by the purified bovine prolactin preparation. Caprine prolactin in plasma and pituitary extracts can be also measured using ovine prolactin as the standard hormone. Cross reactions of pituitary extracts from various non-ruminant species with bovine prolactin antiserum were not detectable. The binding of antibody to 131I labeled bovine prolactin was not inhibited by other pituitary hormones. Bovine prolactin added to plasma was recovered quantitatively. The half-life of injected bovine prolactin in the lactating cow was 29 min.
