Abstract
The regulation of IGF secretion in pregnancy and in the fetus is poorly understood. 10 triplet bearing ewes were fed maintainance plus control abomasal infusion (n=3), plus glucose infusion (n=3), plus casein (n=2), plus glucose and casein (n=2) through the last 42 days of gestation to provide a range of substrate availability. Birth weight (BW) was not affected. 18-27 days before birth, multiple maternal plasma samples were taken at fixed times relative to meals. Maternal PL levels were decreased by casein (p < 0.05) but not by glucose infusion. A negative correlation (p < 0.05) was seen between PL and IGF-1 (by RIA)(r=-0.72). There was a positive correlation between PL and IGF-2 (by rat placental RRA) (r=0.64). There was a strong inverse correlation between maternal IGF-1 and IGF-2 (r=-0.94). The correlation between nonesterified free fatty acids and the IGF-2/IGF-1 ratio was 0.81. A similar correlation to PL was 0.66. There was a correlation (p < 0.05) between cord IGF-1 levels and BW. Multiple linear regression showed an interaction between cord IGF-1, Ins and BW (p < 0.001) which explained 63% of the variation in BW. These findings suggest an interaction in the late gestation ewe between the relative secretion of IGF-1 and IGF-2, metabolic status and PL secretion. IGF-2 may be the mediator of the lipolytic action of PL. The neonatal observations support the concept that fetal IGF-1 and Ins are important detirminants of fetal growth.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Gluckman, P., Butler, J. & Barry, T. 99 INSULIN-LIKE GROWTH FACTORS (IGF), PLACENTAL LACTOGEN QQ (PL), INSULIN (Ins) AND SUBSTRATES IN THE PREGNANT EWE AND NEWBORN LAMB. Pediatr Res 19, 620 (1985). https://doi.org/10.1203/00006450-198506000-00119
Issue Date:
DOI: https://doi.org/10.1203/00006450-198506000-00119