[Release of neurophysins during suckling in the lactating woman].

Using radioimmunoassay for total immunoreactive blood neurophysins (I.R.Neur.) we demonstrate a significant increase 30' after the onset of suckling in 26 normal carefully studied lactating women. On the first day postpartum a constant increase is only observed in 12 patients whilst a significant increase is clearly shown for all patients from the 2nd to the 6th day. These variations are similar to those observed for prolactin blood levels; there is however no relation between basal, suckling stimulated, or ergocryptin inhibited prolactin blood level on the one hand and I.R.Neur. blood level on the other hand.