Degradation of atrial natriuretic factor in mouse blood in vitro and in vivo: role of enkephalinase (EC 3.4.24.11).

ABSTRACT

The half-life of 125I-ANF (99-126) in mouse blood in vivo, evaluated after HPLC analysis, was approximately 0.5 min. This value was nearly doubled in mice pretreated with sinorphan, an enkephalinase inhibitor. 125I-ANF is also hydrolyzed by mouse blood in vitro but its half-life is much longer and only marginally modified by an enkephalinase inhibitor. Hence, although the peptidase is present in blood plasma and cells, its rate-limiting participation in the clearance of the hormone in vivo does not occur at the blood level.