Myogenic expression of an injectable protease-resistant growth hormone-releasing hormone augments long-term growth in pigs.
Ectopic expression of a new serum protease-resistant porcine growth hormone-releasing hormone, directed by an injectable muscle-specific synthetic promoter plasmid vector (pSP-HV-GHRH), elicits growth in pigs. A single 10 mg intramuscular injection of pSP-HV-GHRH DNA followed by electroporation in three-week-old piglets elevated serum GHRH levels by twofold to fourfold, enhanced growth hormone secretion, and increased serum insulin-like growth factor-I by threefold to sixfold over control pigs. After 65 days the average body weight of the pigs injected with pSP-HV-GHRH was approximately 37% greater than the placebo-injected controls and resulted in a significant reduction in serum urea concentration, indicating a decrease in amino acid catabolism. Evaluation of body composition indicated a uniform increase in mass, with no organomegaly or associated pathology.
Draghia-Akli
R
R
Department of Cell Biology, Baylor College of Medicine, Houston, TX 77030, USA. ada@bcm.tmc.edu
Fiorotto
M L
ML
Hill
L A
LA
Malone
P B
PB
Deaver
D R
DR
Schwartz
R J
RJ
D000818:Animals; D002478:Cells, Cultured; D010450:Endopeptidases / Q000378:metabolism*; D005786:Gene Expression Regulation; D018014:Gene Transfer Techniques; D013006:Growth Hormone / Q000378:metabolism; D013007:Growth Hormone-Releasing Hormone / Q000235:genetics / Q000494:pharmacology*; D007273:Injections, Intramuscular; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D024510:Muscle Development; D018482:Muscle, Skeletal / Q000254:growth & development / Q000378:metabolism*; D010957:Plasmids; D013552:Swine / Q000254:growth & development*; D015430:Weight Gain
D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; D010450:Endopeptidases