Fetal and placental growth in the rat following differential reduction of litter size.
The effects on fetal and placental growth of differential litter size reduction on day 10 (LR10) and day 13 (LR13) were determined in the rat. LR10 resulted in significant increments in placental weight, fetal body and brain weight, and brain protein content in the survivors at day 21. A marginal effect on brain cellularity (DNA) was observed. Values for these parameters generally followed the extent of reduction. Placenta weight was also related to original litter size. In contrast, LR13 which was associated with survival of supernumerary placentae (those without a fetus) produced no growth enhancement. Prenatal development was discussed in terms of general systemic influences and hormonal regulatory mechanisms.
D000818:Animals; D001923:Brain Chemistry; D004247:DNA / Q000032:analysis; D005260:Female; D005333:Fetus / Q000502:physiology*; D008098:Litter Size; D009419:Nerve Tissue Proteins / Q000032:analysis; D009929:Organ Size; D010920:Placenta / Q000502:physiology*; D011247:Pregnancy; D051381:Rats
D009419:Nerve Tissue Proteins; D004247:DNA