Enzyme immunoassay of somatostatin(SS)-like immunoreactive substance in bovine milk.

Abstract
A sensitive and specific enzyme immunoassay (EIA) for somatostatin (SS)-like immunoreactivity (SS-LI) was developed with the use of .beta.-D-galactosidase labeled antigen. The minimum amount of SS-like immunoreactive substance (SS-IS) detectable by this method was 1.0 fmol/well (25 pmol/l). The level of SS-IS in bovine foremilk was about 20 pmol/l, and the level was unchanged after delivery. On the other hand, the levels of gastrin releasing peptide (GRP)-IS and vasoactive intestinal polypeptide (VIP)-IS in bovine foremilk were very high, but fell during 1 week after delivery to about 10% of those in foremilk.