Effects of vasoactive intestinal polypeptide and substance P on human intramyometrial arteries and stem villous arteries in term pregnancy.
The effects of vasoactive intestinal polypeptide (VIP) and substance P on isolated human intramyometrial arteries and fetal stem villous arteries obtained from term pregnant women were compared. Ring preparations of small intramyometrial arteries and fetal stem villous arteries obtained at caesarean section were mounted in organ baths, and isometric tension was recorded. None of the peptides affected resting tension. In intramyometrial arteries precontracted by vasopressin (2.8 x 10(-9) M) both substance P (10(-12) to 10(-8) M) and VIP (10(-8) to 10(-6) M) caused relaxation. In fetal stem villous arteries precontracted by prostaglandin F2 alpha (10(-5) M) cumulative addition of substance P (10(-11) to 10(-6) M) did not produce significant changes in tension as compared with controls, while addition of single doses produced moderate relaxation. VIP (10(-8) to 10(-6) M) induced relaxation with similar effects for the addition of cumulative and single doses. The responses to VIP and substance P remained unaffected after pretreatment by atropine (10(-6) M), propranolol (10(-6) M), and indomethacin (10(-6) M). The results support a role for VIP and substance P in the regulation of uteroplacental blood flow in term pregnancy.
Hansen
V
V
Department of Obstetrics and Gynaecology, University of Aarhus, Denmark.
Maigaard
S
S
Allen
J
J
Forman
A
A
D001158:Arteries / Q000187:drug effects; D005260:Female; D006801:Humans; D009131:Muscle, Smooth, Vascular; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D013373:Substance P / Q000494:pharmacology*; D014469:Umbilical Arteries / Q000187:drug effects*; D014599:Uterus / Q000098:blood supply*; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
D013373:Substance P; D014660:Vasoactive Intestinal Peptide