Placental barrier to atrial natriuretic peptide in rats.
Transplacental passage of 125I-labelled synthetic rat atrial natriuretic peptide (ANP) was investigated in 20-day pregnant rats under pentobarbitone anesthesia. Although significant quantities of radioactivity were detected in the fetal plasma after maternal injections and in the maternal plasma after fetal injections of 125I-labelled synthetic ANP, no fraction of the placentally transferred radioactivity was due to intact ANP. Despite a rapid maternal and fetal metabolism of ANP, both maternal and fetal plasma radioactivity remained relatively stable for at least 3 h and less than 10% of the injected radioactivity was excreted in the maternal urine during a 90-min period. It is concluded that ANP is not transported in either direction across the placenta in rats.
Mulay
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Endocrine Laboratory, Royal Victoria Hospital, Montréal, Qué., Canada.
Varma
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D000653:Amniotic Fluid / Q000032:analysis; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood / Q000378:metabolism*; D005260:Female; D005333:Fetus / Q000378:metabolism*; D008431:Maternal-Fetal Exchange; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D009320:Atrial Natriuretic Factor