Effects of maternal plasmid GHRH treatment on offspring growth.
To differentiate prenatal effects of plasmid growth hormone-releasing hormone (GHRH) treatment from maternal effects mediated by lactation on long-term growth of offspring, a cross-fostering study was designed. Pregnant sows (n=12) were untreated (n=6) or received either a Wt-GHRH (n=2) or HV-GHRH (n=4) plasmid. At birth, half of each litter was cross-fostered (treated to controls and controls to treated only). Piglets from plasmid-injected sows were heavier at birth (HV-GHRH, 1.65+/-0.07kg; Wt-GHRH, 1.46+/-0.05kg vs. Controls, 1.27+/-0.03kg; P>or=0.001) and at weaning (Wt-GHRH, 6.01+/-0.21kg and HV-GHRH, 6.34+/-0.15kg vs. Controls, 5.37+/-0.14kg; P>or=0.02, respectively). Control piglets cross-fostered to plasmid-injected sows grew faster to weaning (Wt-GHRH, 5.61+/-0.15kg and HV-GHRH, 5.70+/-0.29kg vs. Controls, 5.08+/-0.22kg; P>0.05, respectively). Piglets from plasmid-injected sows that suckled on control sows were larger than control piglets on control sows (Wt-GHRH, 5.93+/-0.20kg and HV-GHRH, 6.2+/-0.19kg vs. Controls, 5.08+/-0.22kg; P>0.05, respectively), but smaller than their littermates left on their treated mothers. The observed improvements were maintained until the end of the study when the offspring were 170-day-old. The results suggest that the improved growth of offspring of GHRH plasmid-treated sows pre-weaning is attributable to improved maternal performance, while after weaning the effects on the pituitary component are relevant.
Khan
Amir S
AS
VGX Pharmaceuticals, Inc., 2700 Research Forest Drive, The Woodlands, TX 77381, USA. akhan@inovio.com
Bodles-Brakhop
Angela M
AM
Fiorotto
Marta L
ML
Draghia-Akli
Ruxandra
R
D000818:Animals; D000833:Animals, Suckling / Q000254:growth & development*; D001823:Body Composition; D005260:Female; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D013007:Growth Hormone-Releasing Hormone / Q000235:genetics / Q000494:pharmacology*; D007774:Lactation / Q000235:genetics; D010865:Pilot Projects; D010902:Pituitary Gland / Q000502:physiology; D010957:Plasmids; D011247:Pregnancy; D013552:Swine
D013007:Growth Hormone-Releasing Hormone