Abstract: Swine pituitary cells were isolated from three-day new born piglet and incubated with DMEM medium in the plating culture method. These cells were treated with GHRP-2 with different concentrations, 0, 10-5, 10-6, 10-7, 10-8 and 10-9 mol/L, for 2 hours.respectively. The results showed that GHRP-2 of 10-5, 10-6, 10-7, 10-8 and 10-9 mol/L all could stimulate the pituitary cells incubated in vitro to excrete GH (P儸 0.05), and the difference among the groups was not significant (P>0.05). Furthermore the swine pituitary cells were treated with GHRP-2 of 10-6 mol/L for 5 to 180 minutes, which showed that GH value were up to peak within 10 to 20 minute. On the other hand, the swine pituitary cells were treated with GHRP-2 of 10-6 mol/L for six times in succession, each time for one hour. The results demonstrated that GHRP-2 could accelerate the release of GH in the first three times, however, the secretion was restrained after the fourth time and the negative influence increased by more treat time. But the identity of the configuration and density of swine pituitary cells observed in microscopes indicated that the succession treated with GHRP-2 could desensitize the swine pituitary cells.

Key words: growth hormone-releasing peptide-2, swine pituitary, growth hormone