Maternal vasoactive intestinal peptide and the regulation of embryonic growth in the rodent.
Vasoactive intestinal peptide (VIP) has been shown to regulate early postimplantation growth in rodents through central nervous system receptors. However, the source of VIP mediating these effects is unknown. Although VIP binding sites are present prenatally, VIP mRNA was not detected in the rat central nervous system before birth and was detected in the periphery only during the last third of pregnancy. In the present study, the embryonic day (E11) rat embryo/trophoblast was shown to have four times the VIP concentration of the E17 fetus and to have VIP receptors in the central nervous system. However, no VIP mRNA was detected in the E11 rat embryo or embryonic membranes by in situ hybridization or reverse transcriptase-PCR. RIA of rat maternal serum revealed a peak in VIP concentration at days E10-E12 of pregnancy, with VIP rising to levels 6-10-fold higher than during the final third of pregnancy. After intravenous administration of radiolabeled VIP to pregnant female mice, undegraded VIP was found in the E10 embryo. These results suggest that maternal tissues may provide neuroendocrine support for embryonic growth through a surge of VIP during early postimplantation development in the rodent.
Section on Developmental and Molecular Pharmacology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
J M
JM
Hill
S K
SK
McCune
R J
RJ
Alvero
G W
GW
Glazner
K A
KA
Henins
S F
SF
Stanziale
J R
JR
Keimowitz
D E
DE
Brenneman
D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000196:embryology; D001923:Brain Chemistry; D004622:Embryo, Mammalian / Q000737:chemistry*; D005314:Embryonic and Fetal Development / Q000502:physiology*; D005260:Female; D017403:In Situ Hybridization; D008431:Maternal-Fetal Exchange; D051379:Mice; D008969:Molecular Sequence Data; D010920:Placenta / Q000737:chemistry; D016133:Polymerase Chain Reaction / Q000379:methods; D011247:Pregnancy; D012333:RNA, Messenger / Q000032:analysis / Q000097:blood; D051381:Rats; D013004:Somatostatin / Q000097:blood; D013116:Spinal Cord / Q000737:chemistry / Q000196:embryology; D014327:Trophoblasts / Q000737:chemistry; D014660:Vasoactive Intestinal Peptide / Q000032:analysis* / Q000097:blood / Q000378:metabolism; D000521:alpha-MSH / Q000097:blood
D012333:RNA, Messenger; D014660:Vasoactive Intestinal Peptide; D013004:Somatostatin; D000521:alpha-MSH