2 MOLECULAR-FORMS OF PEPTIDE YY (PYY) ARE ABUNDANT IN HUMAN BLOOD - CHARACTERIZATION OF A RADIOIMMUNOASSAY RECOGNIZING PYY-1-36 AND PYY-3-36

Two endogenous forms of PW are abundant in man and dog, PW 1-36 (PYY-I) and PYY 3-36 (PYY-II). PW-II is a major molecular form of PW in human colon, but it is not known, whether PYY-II is also released into the circulating blood. Several radioimmunoassays for measuring PYY-I in plasma have been developed, but it has not been reported, whether they equally detect PYY-II, We characterize a radioimmunoassay for measuring PYY in human plasma which equally recognizes PW-I and PYY-II. Using this radioimmunoassay and reversed phase HPLC we demonstrate the existence of two forms of PYY in human blood, coeluting with synthetic PW-I and PW-II.