Myogenic expression of an injectable protease-resistant growth hormone-releasing hormone augments long-term growth in pigs

Nat Biotechnol. 1999 Dec;17(12):1179-83. doi: 10.1038/70718.


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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Cells, Cultured
  • Endopeptidases / metabolism*
  • Gene Expression Regulation*
  • Gene Transfer Techniques
  • Growth Hormone / metabolism
  • Growth Hormone-Releasing Hormone / genetics
  • Growth Hormone-Releasing Hormone / pharmacology*
  • Injections, Intramuscular
  • Insulin-Like Growth Factor I / metabolism
  • Male
  • Muscle Development
  • Muscle, Skeletal / growth & development
  • Muscle, Skeletal / metabolism*
  • Plasmids
  • Swine / growth & development*
  • Weight Gain


  • Insulin-Like Growth Factor I
  • Growth Hormone
  • Growth Hormone-Releasing Hormone
  • Endopeptidases