Effects of Cholecystokinin Octapeptide on the Release of Growth Hormone from the Perifused Bovine Pituitary In Vitro

Abstract

The effect of cholecystokinin octapeptide (CCK-8) was studied on the release of growth hormone (GH) from perifused adenohypophyses of steers. Perifusion with media containing 10^-7, 10^-8 and 10^-9M CCK-8 for 90min significantly increased the mean GH concentrations during the treatments by Δ7.36 (P<0.01), 13.31 (P<0.01) and Δ5.64 (P<0.05) ng/ml respectively compared with the control group. There was no significant difference in the rates of increase in GH among the three molar perifusion groups. The present results indicate that CCK-8 acts directly on the adenohypophysis to stimulate release of GH in cattle.