GHRP-6 is a growth hormone-releasing peptide that has been shown to release growth hormone (GH) in vivo in several different species. A study conducted by Rico et. Al, studied the effects of GHRP-6 in vitro in bovine somatotropes that were separated through elutriation. GHRP-6 was administered in doses from 10(-8) M to 10(-5)M as well as 10(-9)M in the pituitary cells of the cows. It was found that all doses stimulated the release of GH, however, maximal stimulation of GH was found at 10(-6)M. The effects of treatment with GHRP-6 were seen at hours 1, 2, 3, and 4 of incubation, with the exception of heifer pituitary cells which did not experience the effects at hour 1 of the incubation period (https://pubmed.ncbi.nlm.nih.gov/10494658/).
Several studies in mice conducted from 1997 to 1999 examined the role that growth hormone-releasing peptides played in preventing heart failure. These studies were limited due to technology and resources but came to the general conclusion that GHRPs were able to prevent cardiovascular failure.