Effects of plasmid growth hormone-releasing hormone treatment during heat stress.
A gene therapy treatment with plasmid-based growth hormone-releasing hormone (GHRH) delivered by electroporation (EP) was investigated during heat stress; 32 primiparous cows received 2.5 mg of a GHRH-expressing myogenic plasmid (pSP-HV-GHRH), while 20 were designated as controls. Offspring of treated animals showed a reduction in mortality (47%; p < 0.02), and survival from birth to 260 days was dramatically improved (0% mortality vs. 21% in controls) along with an increase in weight gain (p < 0.05). Milk production was increased compared to controls with an average yield gain of 421 kg/cow (p = 0.028). Prolactin (PRL) levels were also significantly increased compared to controls (p < 0.05). The second pregnancy rate was improved by GHRH treatment (53.3% vs. 30.8%). This study shows that the use of plasmid-mediated therapy delivered by EP can maintain health status during periods of heat stress, important for both animals and potentially humans in hot, challenging climates.
Brown
Patricia A
PA
VGX Animal Health, The Woodlands, Texas 77381, USA.
Bodles-Brakhop
Angela M
AM
Draghia-Akli
Ruxandra
R
D000595:Amino Acid Sequence; D000818:Animals; D000831:Animals, Newborn; D002417:Cattle; D005260:Female; D013007:Growth Hormone-Releasing Hormone / Q000008:administration & dosage* / Q000737:chemistry / Q000235:genetics*; D006358:Hot Temperature; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics; D011247:Pregnancy; D013312:Stress, Physiological / Q000628:therapy*
D013007:Growth Hormone-Releasing Hormone