Uteroplacental insufficiency alters the mammary gland response to lactogenic hormones in vitro.
Adequate mammary development and coordinated actions of lactogenic hormones are essential for the initiation of lactation. Pregnancies compromised by uteroplacental insufficiency impair mammary development and lactation, further slowing postnatal growth. It is not known whether the initiation of lactation or galactopoesis is compromised. Uteroplacental insufficiency induced in rats by bilateral uterine vessel ligation (Restricted) or sham surgery (Control) on Day 18 of gestation preceded collection of mammary tissue on Day 20 of pregnancy. Mammary explants were cultured with combinations of insulin, cortisol and prolactin and analysed for alpha-lactalbumin and beta-casein gene expression. Mammary tissue from late pregnant Restricted rats had elevated alpha-lactalbumin, but not beta-casein, mRNA, which is consistent with premature lactogenesis resulting from an early decline in peripheral maternal progesterone. Explants from Restricted rats were more responsive to hormone stimulation after 3 days in culture, indicating that compromised galactopoesis, not lactogenesis, most likely leads to the reduced growth of suckled pups.
O'Dowd
Rachael
R
Department of Physiology, The University of Melbourne, Victoria 3010, Australia.
Wlodek
Mary E
ME
Nicholas
Kevin R
KR
D000818:Animals; D000833:Animals, Suckling; D002364:Caseins / Q000235:genetics; D002478:Cells, Cultured; D005260:Female; D005317:Fetal Growth Retardation / Q000235:genetics / Q000473:pathology / Q000503:physiopathology*; D020567:Fetal Weight; D005786:Gene Expression Regulation / Q000187:drug effects*; D007768:Lactalbumin / Q000235:genetics; D008297:Male; D008321:Mammary Glands, Animal / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D009929:Organ Size; D021041:Placental Circulation / Q000502:physiology*; D011247:Pregnancy; D011388:Prolactin / Q000494:pharmacology*; D051381:Rats; D011921:Rats, Inbred WKY
D002364:Caseins; D011388:Prolactin; D007768:Lactalbumin